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When processing unallocated space entries we didn't properly release the
inode bh. Fix it.
Signed-off-by: Jan Kara <jack@suse.cz>
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udf_read_inode() copies the on-disk lengthAllocDescs field of a USE
(unallocSpaceEntry) inode into iinfo->i_lenAlloc without checking that
it fits in the i_data buffer that is subsequently allocated for the
inode. udf_count_free_table(), called from udf_statfs(), then walks the
allocation descriptor array up to i_lenAlloc bytes, so a crafted UDF
image with lengthAllocDescs larger than (blocksize - sizeof(struct
unallocSpaceEntry)) causes udf_get_fileshortad() to read past the end
of the kmalloc'd i_data buffer.
KASAN report from mounting a crafted UDF image and calling statfs()
from an unprivileged process:
BUG: KASAN: slab-out-of-bounds in udf_get_fileshortad+0x126/0x130
Read of size 4 at addr ffff8880042137d8 by task poc/65
Call Trace:
dump_stack_lvl+0x53/0x70
print_report+0xce/0x610
kasan_report+0xce/0x100
udf_get_fileshortad+0x126/0x130
udf_current_aext+0x3c4/0xa10
udf_next_aext+0x241/0x440
udf_statfs+0xb7d/0x11c0
statfs_by_dentry+0x117/0x1e0
user_statfs+0xac/0x130
__do_sys_statfs+0x80/0xe0
do_syscall_64+0x102/0x5a0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Reject USE inodes whose lengthAllocDescs would place descriptors past
the end of the i_data buffer, mirroring the checks the rest of the UDF
code performs on descriptor lengths.
This bug was discovered by Artiphishell's vTriage pipeline, which
generated a userspace reproducer that reliably triggers the KASAN
report on an unpatched kernel. The fix below was drafted with the
Claude coding assistant; a userspace reproducer (and the crafted UDF
image) is available on request.
Assisted-by: LLM
Signed-off-by: Jay Vadayath <jay@artiphishell.com>
Link: https://patch.msgid.link/20260717184021.13476-1-jay@artiphishell.com
Signed-off-by: Jan Kara <jack@suse.cz>
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New HW no longer implements a separate class for latency-sensitive QPs
and advertises this by a new cap bit.
Signed-off-by: Leon Romanovsky <leon@kernel.org>
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resctrl fs commands are becoming more powerful with, for example, a user able
to use syntax like '*' to make broad configuration changes. Such commands that
span multiple domains may result in more than one message printed to the
last_cmd_status buffer with more planned.
Issue "[truncated]" when displaying the last_cmd_status buffer to communicate
if it overflowed. Upon encountering this, user space is expected to combine
details about the failure found in info/last_cmd_status with related resctrl
files to learn the accurate system state after the command failure.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ben Horgan <ben.horgan@arm.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://patch.msgid.link/eb3d1aaa41d1f2bf6b1bb26ceafd52f04912121d.1782857711.git.reinette.chatre@intel.com
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fs/erofs/decompressor_lzma.c sizes the module-global MicroLZMA stream
pool from num_possible_cpus() when the lzma_streams module parameter is
unset, then z_erofs_load_lzma_config() preallocates one image-supplied
dictionary per stream, accepting dictionaries up to 8 MiB. On high-CPU
systems, a small EROFS image can pin hundreds of MiB of vmalloc-backed
decoder state until the erofs module is unloaded.
Impact: An EROFS image mounted by the system can pin up to 8 MiB of
vmalloc memory per LZMA stream, either as intended or unexpectedly.
Bound the default stream count by a new
CONFIG_EROFS_FS_ZIP_LZMA_DEFAULT_MAX_STREAMS option, default 16, so the
worst-case default preallocation is 128 MiB if the number of CPUs is no
less than 16 while preserving the existing per-image dictionary limit.
An explicit lzma_streams module parameter is still honoured as-is, so
administrators who deliberately size the pool are not affected.
Fixes: 622ceaddb764 ("erofs: lzma compression support")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
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Previously, backing files for page cache sharing were set up with
f_path left as NULL (only f_inode was valid). It worked, but a recent
mincore fix relies on f_path.mnt and crashes (found by "erofs/028" on
7.2-rc4):
BUG: kernel NULL pointer dereference, address: 0000000000000018
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP PTI
CPU: 3 UID: 0 PID: 675528 Comm: fincore Not tainted 7.2.0-rc4-00002-g[]-dirty #1 PREEMPT(lazy)
Hardware name: Red Hat KVM, BIOS 1.16.0-4.al8 04/01/2014
RIP: 0010:__do_sys_mincore+0xc0/0x2c0
...
Specify valid paths using valid disconnected dentries together with
erofs_ishare_mnt instead of leaving f_path empty, so they are more
like real backing files in a pseudo filesystem and standard
backing_file_open() can be used directly.
Fixes: e187bc02f8fa ("mm: do file ownership checks with the proper mount idmap")
Acked-by: Hongbo Li <hongbohbli@tencent.com>
Signed-off-by: Gao Xiang <xiang@kernel.org>
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User space expects last_cmd_status to contain additional information if any
resctrl command fails.
A resctrl command may be blocked on the rdtgroup_mutex waiting for another
command to finish and find that once the mutex is available that the resource
group has since been deleted.
In this scenario the command will fail while last_cmd_status contains either
"ok" if the last_cmd_status buffer is empty or an outdated error from
a previous command failure if last_cmd_status buffer has content.
Include clearing of last_cmd_status buffer as part of rdtgroup_kn_lock_live()
that is used to obtain access and needed locking to a resource group before
attempting a command on the group.
With the last_cmd_status buffer ready, provide an appropriate message to user
space if the resource group has been deleted.
No last_cmd_status treatment is needed for the remaining failure of
rdtgroup_kn_lock_live() encountering a non-existent resource group since that
could only occur during an attempt to obtain a resource group lock on a file
in info/ which is an invalid usage.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://patch.msgid.link/9982141ec6f3ec18e0c53d7feabb19651583cf0e.1782857711.git.reinette.chatre@intel.com
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info/last_cmd_status is intended to contain more information if a write to
any resctrl file fails. Writes to max_threshold_occupancy did not receive
last_cmd_status support during initial last_cmd_status enabling. Add it now.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://patch.msgid.link/dfc60cf5324e15612db075b0987bd89c490fbad5.1782857711.git.reinette.chatre@intel.com
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The cifs.idmap key type stores its payload length in key->datalen, which
is limited to U16_MAX. Accepting a larger key payload truncates the
recorded length and can make later users interpret the payload using
inconsistent bounds.
Reject oversized preparsed payloads before allocating or copying them.
This keeps key->datalen consistent with the stored data for both inline
and separately allocated idmap payloads.
Signed-off-by: Li Qiang <liqiang01@kylinos.cn>
Signed-off-by: Steve French <stfrench@microsoft.com>
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Both branches of the check return the same value, so the check has
no effect. Remove it and return the value directly.
This is the result of running the Coccinelle script from
scripts/coccinelle/misc/cond_return_no_effect.cocci.
Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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CIFSSMBRead(), CIFSSMBWrite() and CIFSSMBWrite2() allocate a request
buffer before checking whether tcon->ses->server is NULL. If that
defensive check ever fails, the helper returns -ECONNABORTED without
releasing the request buffer.
Fix these leaks by releasing the allocated request buffer before
returning from these error paths. Use cifs_small_buf_release() for the
buffers allocated by small_smb_init() and cifs_buf_release() for the
buffer allocated by smb_init().
The bug was first flagged by an experimental analysis tool we are
developing for kernel memory-management bugs while analyzing
v6.13-rc1. The tool is still under development and is not yet publicly
available. Manual inspection confirms that the bug is still
present in v7.1.1.
An x86_64 allyesconfig build showed no new warnings.
Runtime validation used a temporary fault-injection hook to force
tcon->ses->server to NULL after request-buffer initialization. On the
unfixed kernel, the harness observed two leaked small request buffers and
one leaked large request buffer, with directed kmemleak dumps confirming
the CIFS buffer allocation stacks. After the fix, no CIFS request-buffer
deltas remained.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Dawei Feng <dawei.feng@seu.edu.cn>
Signed-off-by: Steve French <stfrench@microsoft.com>
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Currently, cifs_get_swn_reg() allocates new registry entries using
GFP_ATOMIC. Since we lock a mutex here, this is clearly not an atomic
context. Use GFP_KERNEL instead.
Also, fix a minor grammatical error in the comment above the function.
Signed-off-by: Fredric Cover <fredric.cover.lkernel@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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A pattern of usage of last_cmd_status was introduced during its enabling in
commit
c377dcfbee80 ("x86/intel_rdt: Add diagnostics when writing the schemata file")
and since copied throughout resctrl to result in the following custom:
..._write()
{
/* Early parsing of input, exit on failure. */
/* Obtain rdtgroup_mutex */
rdt_last_cmd_clear(); /* Clear last_cmd_status buffer */
/*
* Act on user command, failures result in detail
* error message in last_cmd_status buffer via
* rdt_last_cmd_puts()/rdt_last_cmd_printf().
*/
/* Release rdtgroup_mutex */
}
If resctrl exits with failure during early parsing of input there are two
possible scenarios:
- The last_cmd_status buffer is empty and a user's read of
info/last_cmd_status returns "ok".
- The last_cmd_status buffer contains details from an earlier ...write()
failure and a user's read of info/last_cmd_status returns this outdated
error description.
Writing to a resctrl file is considered a "resctrl command" and the resctrl
documentation states the following about the last_cmd_status file:
"If the command failed, it will provide more information that can be
conveyed in the error returns from file operations."
Neither of the current scenarios is correct behavior.
Move early input parsing to be done with rdtgroup_mutex held after the
last_cmd_status buffer is cleared. Let info/last_cmd_status be accurate
when an error is encountered during parsing of user command.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ben Horgan <ben.horgan@arm.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://patch.msgid.link/c9eba0ef3b9a72b845b4ae02ecd7c098ed8bf06f.1782857711.git.reinette.chatre@intel.com
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs fixes from Christian Brauner:
- vfs: Preserve the ACL_DONT_CACHE state in forget_cached_acl().
ACL_DONT_CACHE is meant to be a permanent opt-out from ACL caching
which FUSE relies on for servers that don't negotiate FUSE_POSIX_ACL.
The helper replaced it with ACL_NOT_CACHED, silently re-enabling the
cache, and as fuse doesn't invalidate the cache for such servers a
properly timed get_acl() returned stale ACLs. Comes with a fuse
selftest reproducing this.
- pidfs:
- Preserve PIDFD_THREAD when a thread pidfd is reopened via
open_by_handle_at(). PIDFD_THREAD shares the O_EXCL bit which
do_dentry_open() strips after the flags have been validated, so
the reopened pidfd silently became a process pidfd. Comes with a
selftest.
- Add a pidfs_dentry_open() helper so the regular pidfd allocation
path and the file handle path share the code that forces O_RDWR
and reapplies the pidfd flags that do_dentry_open() strips.
- Handle FS_IOC32_GETVERSION in the compat ioctl path.
- Make pidfs_ino_lock static.
- iomap:
- Fix the block range calculation in ifs_clear_range_dirty() so a
partial clear doesn't drop the dirty state of blocks the range
only partially covers.
- Support invalidating partial folios so a partial truncate or hole
punch with blocksize < foliosize doesn't leave stale dirty bits
behind.
- Only set did_zero when iomap_zero_iter() actually zeroed
something.
- Guard ifs_set_range_dirty() and ifs_set_range_uptodate() against
zero-length ranges where the unsigned last-block calculation
underflows and bitmap_set() writes far beyond the ifs->state
allocation.
- Don't merge ioends with different io_private values as the merge
could leak or corrupt the private data of the individual ioends.
- exec:
- Raise bprm->have_execfd only once the binfmt_misc interpreter has
actually been opened. The flag was set as soon as a matching 'O'
or 'C' entry was found. If the interpreter open failed with
ENOEXEC the exec fell through to the next binary format with
have_execfd raised but no executable staged and begin_new_exec()
NULL derefed past the point of no return.
- Fix an unsigned loop counter wrap in transfer_args_to_stack() on
nommu. An overlong argument or environment string pushes bprm->p
below PAGE_SIZE, the stop index becomes zero, and the loop never
terminates, wrapping its counter and copying garbage from in
front of the page array into the new process stack.
- Make binfmt_elf_fdpic only honour the first PT_INTERP like
binfmt_elf does. Each additional PT_INTERP overwrote the previous
interpreter, leaking the name allocation and the interpreter file
reference together with the write denial open_exec() took,
leaving the file unwritable for as long as the system runs.
- overlayfs:
- Compare the full escaped xattr prefix including the trailing dot.
An xattr like "trusted.overlay.overlayfoo" was misclassified as
an escaped overlay xattr.
- Check read access to the copy_file_range() source with the
source's mounter credentials.
- super: Thawing a filesystem whose block device was frozen with
bdev_freeze() deadlocked. Dropping the last block layer freeze
reference from under s_umount ends up in fs_bdev_thaw() which
reacquires s_umount on the same task. Pin the superblock with an
active reference instead and call bdev_thaw() without holding
s_umount.
- procfs: Return EACCES instead of success when the ptrace access check
for namespace links fails.
- afs: Use afs_dir_get_block() rather than afs_dir_find_block() for
block 0 in afs_edit_dir_remove(), matching afs_edit_dir_add().
- Push the memcg gating of ->nr_cached_objects() down into the btrfs
and shmem callbacks instead of skipping every callback during
non-root memcg reclaim. The blanket check short-circuited XFS whose
inode reclaim hook is intentionally driven from per-memcg contexts to
free memcg-charged slab.
- eventpoll: Pin files while checking reverse paths.
Since struct file became SLAB_TYPESAFE_BY_RCU a concurrent close
could free and recycle the file under the check which then took and
dropped the f_lock of whatever live file now occupies that slot.
* tag 'vfs-7.2-rc5.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (24 commits)
super: fix emergency thaw deadlock on frozen block devices
pidfs: make pidfs_ino_lock static
eventpoll: pin files while checking reverse paths
fs: push nr_cached_objects memcg gating into individual filesystems
afs: Fix afs_edit_dir_remove() to get, not find, block 0
iomap: prevent ioend merge when io_private differs
iomap: add comments for ifs_clear/set_range_dirty()
iomap: fix out-of-bounds bitmap_set() with zero-length range
iomap: fix incorrect did_zero setting in iomap_zero_iter()
iomap: support invalidating partial folios
iomap: correct the range of a partial dirty clear
fs/super: fix emergency thaw double-unlock of s_umount
pidfs: handle FS_IOC32_GETVERSION in compat ioctl
ovl: check access to copy_file_range source with src mounter creds
proc: Fix broken error paths for namespace links
pidfs: add pidfs_dentry_open() helper
selftests/pidfd: check PIDFD_THREAD survives open_by_handle_at()
pidfs: preserve thread pidfds reopened by file handle
ovl: fix trusted xattr escape prefix matching
selftests/fuse: add ACL_DONT_CACHE regression test
...
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do_thaw_all_callback() calls bdev_thaw() while holding sb->s_umount
exclusively. If the block device was frozen via bdev_freeze() dropping
the last block layer freeze reference calls fs_bdev_thaw() which
reacquires s_umount:
do_thaw_all_callback(sb)
super_lock_excl(sb) # holds sb->s_umount
bdev_thaw(sb->s_bdev)
mutex_lock(&bdev->bd_fsfreeze_mutex)
# bd_fsfreeze_count drops 1 -> 0
bd_holder_ops->thaw == fs_bdev_thaw
get_bdev_super(bdev)
bdev_super_lock(bdev, true)
super_lock(sb, true)
down_write(&sb->s_umount) # same task: deadlock
The emergency thaw worker deadlocks against itself holding both
s_umount and bd_fsfreeze_mutex. That fscks any subsequent unmount,
freeze, or thaw of that filesystem and block device.
[ 81.878470] sysrq: Show Blocked State
[ 81.880140] task:kworker/0:1 state:D stack:0 pid:11 tgid:11 ppid:2 task_flags:0x4208060 flags:0x00080000
[ 81.884876] Workqueue: events do_thaw_all
[ 81.886656] Call Trace:
[ 81.887759] <TASK>
[ 81.888763] __schedule+0x579/0x1420
[ 81.890372] schedule+0x3a/0x100
[ 81.891794] schedule_preempt_disabled+0x15/0x30
[ 81.893848] rwsem_down_write_slowpath+0x1ea/0x900
[ 81.895191] ? __pfx_do_thaw_all_callback+0x10/0x10
[ 81.896528] down_write+0xbd/0xc0
[ 81.897505] super_lock+0x91/0x180
[ 81.898457] ? __mutex_lock+0xa99/0x1140
[ 81.900748] ? __mutex_unlock_slowpath+0x1f/0x400
[ 81.902069] bdev_super_lock+0x5b/0x150
[ 81.903132] get_bdev_super+0x10/0x60
[ 81.904042] fs_bdev_thaw+0x23/0xf0
[ 81.904755] bdev_thaw+0x82/0x100
[ 81.905484] do_thaw_all_callback+0x2c/0x50
[ 81.906298] __iterate_supers+0x5d/0x130
[ 81.907067] do_thaw_all+0x20/0x40
[ 81.907739] process_one_work+0x206/0x5e0
[ 81.908545] worker_thread+0x1e2/0x3c0
[ 81.909339] ? __pfx_worker_thread+0x10/0x10
[ 81.910171] kthread+0xf4/0x130
[ 81.910799] ? __pfx_kthread+0x10/0x10
[ 81.911528] ret_from_fork+0x2e2/0x3b0
[ 81.912259] ? __pfx_kthread+0x10/0x10
[ 81.913010] ret_from_fork_asm+0x1a/0x30
[ 81.913806] </TASK>
bdev_super_lock() even documents the violated requirement with
lockdep_assert_not_held(&sb->s_umount).
Acquiring bd_fsfreeze_mutex under s_umount also inverts the
bd_fsfreeze_mutex vs. s_umount ordering established by
bdev_{freeze,thaw}() and can thus ABBA against a concurrent block-layer
freeze even when the recursive path isn't hit.
Fix this by not holding s_umount around the bdev_thaw() loop at all. Pin
the superblock with an active reference instead as
filesystems_freeze_callback() does. The active reference keeps the
superblock from being shut down and so ->s_bdev stays valid without
holding s_umount. The block-layer-held freeze is dropped by
fs_bdev_thaw() with FREEZE_MAY_NEST | FREEZE_HOLDER_USERSPACE exactly as
a regular unfreeze would and thaw_super_locked() handles
filesystem-level freezes as before.
The emergency thaw path has deadlocked like this in one form or
another for a long long time but the current exclusively-held
shape dates back to commit [1] where thaw_bdev() already ended in
thaw_super() with s_umount held by do_thaw_all_callback().
Fixes: 08fdc8a0138a ("buffer.c: call thaw_super during emergency thaw") [1]
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260723-work-super-emergency_thaw-v1-1-7c315c600245@kernel.org
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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During schemata file write handling there is one error exit path labeled
"out" that handles all cleanup and unlocking needed on exit. The staged
configs cleared during an error exit may not have been used at the time
of exit making the clearing of the staged configs unnecessary.
Access the exit code using two labels and only clear the staged
configuration if it was in use at the time of exit. Doing so makes the
code flow obvious and simplifies upcoming changes that improve the
handling of failures during early input parsing.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://patch.msgid.link/4cdd79d612dc6d62ccd490e1c31298025d66d385.1782857711.git.reinette.chatre@intel.com
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Pull smb server fixes from Steve French:
"This contains eight ksmbd fixes covering POSIX ACL handling, SMB
signing enforcement, DACL parsing and construction hardening, session
lifetime handling, and validation of malformed transform and
compressed SMB2 requests:
- preserve inherited POSIX ACL mask when creating objects.
- enforce the session signing requirement for plaintext SMB requests.
- harden DACL/ACE processing against size overflows, incomplete ACE
copies, and undersized SIDs.
- defer teardown of a previous session until NTLM authentication
succeeds.
- reject undersized encryption-transform and decompressed SMB2
requests before they can reach normal SMB2 request processing"
* tag 'v7.2-rc4-smb3-server-fixes' of git://git.samba.org/ksmbd:
ksmbd: reject undersized decompressed SMB2 requests
ksmbd: validate minimum PDU size for transform requests
ksmbd: defer destroy_previous_session() until after NTLM authentication
ksmbd: validate ACE size against SID sub-authorities
ksmbd: restore DACL size on check_add_overflow() to avoid malformed ACL
ksmbd: bound DACL dedup walk to copied ACEs
ksmbd: enforce signing required by the session
ksmbd: preserve VFS inherited POSIX ACL mask
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Pull ceph fixes from Ilya Dryomov:
"A bunch of assorted fixes with the majority being hardening against
malformed input and invalid data scenarios that don't happen in real
deployments but can be utilized to trigger use-after-free and similar
issues, some error path leak fixups and two patches from Max to avoid
a potential hang in __ceph_get_caps() and unintended nesting of
current->journal_info while handling replies from the MDS.
All marked for stable"
* tag 'ceph-for-7.2-rc5' of https://github.com/ceph/ceph-client:
ceph: avoid fs reclaim while using current->journal_info
ceph: add owner/capability checks for CEPH_IOC_SET_LAYOUT*
ceph: fix hanging __ceph_get_caps() with stale mds_wanted
rbd: Reset positive result codes to zero in object map update path
libceph: bound pg_{temp,upmap,upmap_items} length to CEPH_PG_MAX_SIZE
libceph: refresh auth->authorizer_buf{,_len} after authorizer update
ceph: fix refcount leak in ceph_readdir()
libceph: guard missing CRUSH type name lookup
libceph: remove debugfs files before client teardown
libceph: bound get_version reply decode to front len
ceph: fix writeback_count leak in write_folio_nounlock()
libceph: fix two unsafe bare decodes in decode_lockers()
ceph: fix pre-auth out-of-bounds read on snaptrace in ceph_handle_caps()
libceph: Reject monmaps advertising zero monitors
libceph: reject zero bucket types in crush_decode
libceph: Fix multiplication overflow in decode_new_up_state_weight()
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Pull fscrypt fixes from Eric Biggers:
"A couple fixes for AI-detected bugs"
* tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/linux:
fscrypt: Avoid dynamic allocation in fscrypt_get_devices()
fscrypt: Add missing superblock check in find_or_insert_direct_key()
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When a shared writable mapping has its valid_size extended by a buffered
write or a page fault, exfat zeroes the page-cache gap below the new
valid_size. A store through the mapping can race with this zeroing and be
overwritten.
Fix this by zeroing the gap lazily. Drop ->map_pages so that every first
write fault goes through exfat_page_mkwrite(), which advances valid_size to
cover the faulting page. With fault-around enabled, a store could install a
writable PTE, skip ->page_mkwrite(), and land past valid_size without
advancing it. Extending valid_size one faulting page at a time also leaves
never-written pages in a large mapping alone.
The gap is filled with block granularity, zeroing only the not-uptodate
blocks and preserving blocks that may hold data stored through the mapping.
On the buffered-write path the invalidate lock is held and the gap is
unmapped before zeroing, so a racing store re-faults and, under the inode
lock, completes only after the gap has been zeroed and valid_size covers
it.
Fixes: 82a81a7352bc ("exfat: add iomap buffered I/O support")
Co-developed-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
|
|
ntfs_utf16_to_nls() appends a trailing NUL to the converted output,
but it passes the caller-supplied size directly to the conversion loop.
For the UTF-8 path, utf16s_to_utf8s() can legitimately fill all
buf_len bytes and return buf_len, after which ntfs_utf16_to_nls()
writes the terminator one byte past the end of the destination buffer.
The same contract problem exists for the NLS path when a converted
character consumes the last available byte.
Reserve one byte for the terminator before doing either conversion.
The function continues to return the number of converted bytes,
excluding the NUL terminator.
Assisted-by: Codex:gpt-5.5
Signed-off-by: Kyle Zeng <kylebot@openai.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
|
|
attr_wof_frame_info() may reuse a cached offsets folio. In that case the
loop can fill the output offsets without calling attr_load_runs_range()
or ntfs_read_run(), leaving err uninitialized before the common return
path. Initialize err to 0 for the successful cached path.
Signed-off-by: Ruoyu Wang <ruoyuw560@gmail.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
|
|
When CONFIG_NTFS3_64BIT_CLUSTER is enabled, sbi->maxbytes_sparse is set
to -1. As a signed loff_t this is -1LL, the most negative value. Any
lseek on a sparse or compressed file passes this as maxsize to
vfs_setpos(), which returns -EINVAL whenever offset > maxsize, and
since -1LL is less than any non-negative offset, every seek fails,
including lseek(fd, 0, SEEK_SET).
The intent of -1 here appears to be "no limit" (matching the spirit of
MAX_LFS_FILESIZE assigned to sbi->maxbytes and sb->s_maxbytes in the
same block), but the signed type makes it the minimum instead of the
maximum.
Fix by assigning MAX_LFS_FILESIZE to sbi->maxbytes_sparse in the
64-bit cluster path, consistent with the other two limits set there.
Observed on a 16 TB NTFS volume with 0xFFFFFEFF total clusters compiled
with CONFIG_NTFS3_64BIT_CLUSTER=y. Sequential reads via dd/cp worked
correctly; any lseek call on sparse files returned EINVAL, preventing
archive managers and other tools from random-accessing files on the
volume. The non-64-bit-cluster path correctly sets maxbytes_sparse to
(1ull << (cluster_bits + 32)) - 1, a large positive value.
Signed-off-by: Senjin <senjin@hatchling.org>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
|
|
When $MFT's ATTR_BITMAP attribute is heavily fragmented, its run list
can span multiple MFT extension records (attribute list entries with
vcn > 0). The non-primary segment handler in ntfs_read_mft() only
processed ATTR_DATA extension segments for MFT_REC_MFT, silently
skipping any ATTR_BITMAP segments. This left sbi->mft.bitmap.run
incomplete, causing wnd_init() to fail with -ENOENT when wnd_rescan()
tried to look up a VCN not covered by the truncated run list.
Observed on a 16 TB NTFS volume (0xFFFFFEFF total clusters) whose MFT
bitmap run list was split across 97 extents in extension records.
wnd_rescan() successfully looked up VCNs 0-122 from the runs loaded
from the base record, then failed at VCN 123 (the last cluster of the
bitmap) whose run was only present in an extension record.
Fix by extending the MFT_REC_MFT special case to also handle
ATTR_BITMAP extension segments, storing their runs into
sbi->mft.bitmap.run the same way the primary segment does.
Signed-off-by: Senjin <senjin@hatchling.org>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
|
|
Hard to say about copy_to_user_iter(), but at least the first splat
looks correct. At the end of fill_name_de(), data layout is:
struct NTFS_DE *e = buf;
...
|<- data_size + sizeof(struct NTFS_DE) ->|<- XXX ->|
buf |-----------------------------------------------------------
|<- ALIGN(data_size, 8) + sizeof(struct NTFS_DE) ->| ;; e->size
If 'buf' was allocated with kmalloc(), XXX remains uninitialized and
passed as such to memcpy() called from hdr_insert_de().
So using kzalloc() for all buffers passed to fill_name_de() looks
the simplest and most safe solution. OTOH if someone would have
said that an overhead of PAGE_SIZE'd memset() is too large, more
fine-granted solution is to memset() XXX only.
Reported-by: syzbot+905d785c4923bea2c1db@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=905d785c4923bea2c1db
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
|
|
ntfs_dir_emit() skips index entries whose fname does not fit in e->size,
but ntfs_dir_count() still accepted them via de_get_fname() alone.
dir_is_empty() can then disagree with readdir: a malformed directory
appears empty in ls while rmdir fails with ENOTEMPTY.
Factor the fname/key bounds check into de_fname_fits() and use it from
ntfs_dir_emit() and de_countable_fname() so count/readdir share the same
entry acceptance rules.
Signed-off-by: Xixin Liu <liuxixin@kylinos.cn>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
|
|
ntfs_reparse_init() and ntfs_objid_init() parse the index root of the
$Extend/$Reparse and $Extend/$ObjId metafiles (the INDEX_ROOT attributes
named $R and $O). They read its type and rule fields through
resident_data(), which does not check that the resident attribute is
large enough to hold them.
mi_enum_attr() accepts a resident attribute with data_off == asize and
data_size == 0. For such an attribute placed last in its MFT record,
resident_data() returns a pointer to the end of the record_size buffer,
so reading root->type / root->rule reads past the allocation.
Use resident_data_ex(attr, sizeof(struct INDEX_ROOT)) and bail out when
it returns NULL, as ntfs_security_init() already does for $SDH / $SII.
The attribute is only parsed while mounting a crafted image, so this
needs CAP_SYS_ADMIN.
BUG: KASAN: slab-out-of-bounds in ntfs_reparse_init (fs/ntfs3/fsntfs.c:2306)
Read of size 4 at addr ffff88801219dc00 by task mount
ntfs_reparse_init (fs/ntfs3/fsntfs.c:2306)
ntfs_fill_super (fs/ntfs3/super.c:1604)
get_tree_bdev_flags (fs/super.c:1703)
vfs_get_tree (fs/super.c:1758)
path_mount (fs/namespace.c:4131)
__x64_sys_mount (fs/namespace.c:4360)
Fixes: 82cae269cfa9 ("fs/ntfs3: Add initialization of super block")
Reported-by: Xiang Mei <xmei5@asu.edu>
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Weiming Wu <weiming3@asu.edu>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
|
|
Fixes: 87caaeef7995 ("pidfs: implement ino allocation without the pidmap lock")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202607231547.ehCQxi0L-lkp@intel.com/
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://patch.msgid.link/20260723160114.291515-1-mjguzik@gmail.com
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
|
|
Pull smb client fixes from Steve French:
- Fix leak in cifs_close_deferred_file()
- Fix resolving MacOS symlinks
- Fix stale file size in readdir
- Update git branches in MAINTAINERS file
- Fix bounds check in cifs_filldir
- Fix checks in parse_dfs_referrals()
- Fix DFS referral checks for malformed packet
* tag 'v7.2-rc4-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
cifs: fix cifsFileInfo leak on kmalloc failure in deferred close drain paths
cifs: prevent readdir from changing file size due to stale directory metadata
smb: client: handle STATUS_STOPPED_ON_SYMLINK responses without a symlink target
Add missing git branch info for cifs and ksmbd to MAINTAINERS file
smb: client: bound dirent name against end of SMB response in cifs_filldir
smb: client: validate DFS referral PathConsumed
|
|
Reading of event data is managed through populating a struct rmid_read with
properties of event needing to be read. This data is dispatched to an
appropriate CPU and upon completion any error can be found in rmid_read::err,
or on success the event data will be in rmid_read::val.
rmid_read::err is not updated in the unlikely scenario that the reading of the
event was dispatched to a wrong CPU. If this ever occurs due to a bug in
resctrl the user space read will return "success" but the data reported will
be invalid.
Ensure accurate error reporting so that if there may be an issue with how
resctrl picks a CPU it could be learned with an error to user space instead of
silent failure.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ben Horgan <ben.horgan@arm.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://patch.msgid.link/6b3c66a49788828bd8c04a6911bd74c91ccd56f3.1782857711.git.reinette.chatre@intel.com
|
|
handle_reply() stores a `ceph_mds_request` pointer in
`current->journal_info` while filling the inode and dentry cache from
an MDS reply.
An allocation in this section can enter direct reclaim and prune
dentries from another filesystem. If this dirties an ext4 inode, ext4
starts a JBD2 transaction. JBD2 interprets the Ceph request in
`current->journal_info` as a journal handle and dereferences the
request's `r_tid` as `h_transaction`, causing a kernel crash, e.g.:
Unable to handle kernel paging request at virtual address 00000000077b4818
[...]
Internal error: Oops: 0000000096000004 [#1] SMP
Modules linked in:
CPU: 6 UID: 0 PID: 2699135 Comm: kworker/6:3 Tainted: G W 6.18.38-i3 #1113 NONE
[...]
Workqueue: ceph-msgr ceph_con_workfn
pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : jbd2__journal_start+0x2c/0x208
lr : __ext4_journal_start_sb+0x100/0x178
[...]
Call trace:
jbd2__journal_start+0x2c/0x208 (P)
__ext4_journal_start_sb+0x100/0x178
ext4_dirty_inode+0x3c/0x90
__mark_inode_dirty+0x58/0x400
iput.part.0+0x2b0/0x370
iput+0x18/0x30
dentry_unlink_inode+0xc0/0x158
__dentry_kill+0x80/0x250
shrink_dentry_list+0x90/0x130
prune_dcache_sb+0x60/0x98
super_cache_scan+0xe8/0x190
do_shrink_slab+0x174/0x388
shrink_slab+0xd8/0x4c0
shrink_node+0x31c/0x908
do_try_to_free_pages+0xd0/0x508
try_to_free_pages+0x11c/0x238
__alloc_frozen_pages_noprof+0x4d0/0xdd0
__folio_alloc_noprof+0x18/0x70
__filemap_get_folio+0x248/0x440
ceph_readdir_prepopulate+0x570/0x9e8
mds_dispatch+0x1424/0x1ba0
ceph_con_process_message+0x74/0xa0
ceph_con_v1_try_read+0x3a0/0x1510
ceph_con_workfn+0x260/0x460
Enter a scoped NOFS allocation context and leave it after clearing
`journal_info`. This prevents filesystem reclaim from recursing into
another filesystem while the field contains Ceph-private data.
Cc: stable@vger.kernel.org
Fixes: 315f24088048 ("ceph: fix security xattr deadlock")
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Reviewed-by: Viacheslav Dubeyko <slava@dubeyko.com>
Reviewed-by: Xiubo Li <xiubo.li@clyso.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
|
|
These permission checks were already missing in the initial
impementation of these ioctls. This Ceph allows any user who owns a
file descriptor to manipulate the layout of any file, even if they
don't have write permissions.
It might be a good idea to guard other ioctls with permission checks
as well or even disallow regular users (even if they own the file) to
manipulate layout settings completely, as this may be abused to DoS
the Ceph servers, but right now, I find it most urgent to have setter
checks at all.
Cc: stable@vger.kernel.org
Fixes: 8f4e91dee2a2 ("ceph: ioctls")
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Reviewed-by: Xiubo Li <xiubo.li@clyso.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
|
|
A reader can hang forever in __ceph_get_caps() when the client no
longer holds `FILE_RD`, but local cap state still says that the
capability is already wanted (via `mds_wanted`).
One way to trigger this is through MDS cap revocation. If another
client performs a conflicting operation, the MDS can revoke `FILE_RD`
from the reader; the next read then has to reacquire `FILE_RD`. If
the cap update that should request `FILE_RD` never reaches the MDS
after `cap->mds_wanted` was raised, the reader is left holding only
non-file caps while local `mds_wanted` still includes the file read
caps.
In that state, try_get_cap_refs() sees `need <= mds_wanted` and
returns 0, so __ceph_get_caps() just waits on `i_cap_wq`. If the cap
update that was supposed to request `FILE_RD never reaches the MDS
after `cap->mds_wanted was` raised, no further request is sent and the
waiter can sleep indefinitely until unrelated cap traffic happens to
wake it up.
The ordering issue is that `cap->mds_wanted` is updated in
__prep_cap() before the `CEPH_MSG_CLIENT_CAPS message` is actually
queued for send. That makes one field serve two different meanings at
once: what this client wants, and what the client believes the MDS
already knows it wants.
A proper fix would be to split those states and track whether a cap
update is actually in flight or has been observed by the MDS.
However, simply moving the `cap->mds_wanted assignment` later would
not be sufficient: queueing the message in the messenger does not
guarantee that the MDS processed that specific wanted set, and
reconnect or message loss can still invalidate that assumption.
Fixing that properly would require a larger rework of the cap state
machine.
To allow simpler backports to stable kernels, this patch implements a
simpler workaround:
- stop waiting forever in __ceph_get_caps(); after a bounded wait,
fall back to the renew path
- make ceph_renew_caps() issue a synchronous `OPEN` request whenever
the inode still does not actually hold the wanted caps, instead of
only calling ceph_check_caps()
The extra issued-vs-wanted check in ceph_renew_caps() is necessary
because the previous test only checked whether the inode still had any
real caps at all. That is not enough after revocation: the client can
still hold something like `pLs` and yet be missing `FILE_RD`
completely. In that case, falling back to ceph_check_caps() is not
sufficient, because it still trusts `cap->mds_wanted` and may resend
nothing. By requiring `(issued & wanted) == wanted` before taking the
asynchronous path, the code only uses ceph_check_caps() when the
`wanted caps` are already actually issued. Otherwise, it sends the
synchronous `OPEN` renew.
This preserves the existing asynchronous fast path when the wanted
caps are already issued, avoids changing cap-state semantics, and
fixes the hang by guaranteeing that a stalled waiter eventually
retries through a path that does not rely on the stale `mds_wanted`
state.
[ idryomov: move CEPH_GET_CAPS_WAIT_TIMEOUT from libceph.h to
mds_client.h, formatting ]
Cc: stable@vger.kernel.org
Fixes: 0a454bdd501a ("ceph: reorganize __send_cap for less spinlock abuse")
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Reviewed-by: Alex Markuze <amarkuze@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
|
|
The ceph_readdir() function allocates a ceph_mds_request via
ceph_mdsc_create_request() and stores it in dfi->last_readdir. In
the directory entry processing loop, if the entry's offset is less
than ctx->pos or if the inode pointer is unexpectedly NULL, the
function returns -EIO without releasing the reference held by
dfi->last_readdir, causing a refcount leak.
Fix this by adding ceph_mdsc_put_request(dfi->last_readdir) before
returning on these error paths. Also set dfi->last_readdir to NULL
for safety, matching the cleanup done at the normal exit.
Cc: stable@vger.kernel.org
Fixes: af9ffa6df7e3 ("ceph: add support to readdir for encrypted names")
Signed-off-by: WenTao Liang <vulab@iscas.ac.cn>
Reviewed-by: Viacheslav Dubeyko <slava@dubeyko.com>
Reviewed-by: Alex Markuze <amarkuze@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
|
|
write_folio_nounlock() increments fsc->writeback_count to track
in-flight writeback operations. On several error paths where the
function returns early (folio lookup failure, snapshot context
allocation failure, and writepages submission failure), the function
returns without calling atomic_long_dec_return() to decrement the
counter.
Each leaked increment keeps the counter above zero, which can prevent
the filesystem from cleanly unmounting or suspending writes.
Add atomic_long_dec_return() calls on all error paths that currently
return without decrementing the counter.
Cc: stable@vger.kernel.org
Fixes: d55207717ded ("ceph: add encryption support to writepage and writepages")
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
|
|
ceph_handle_caps() reads snap_trace_len from the wire-format
ceph_mds_caps header and uses it unconditionally to build a fake
end pointer (snaptrace + snaptrace_len) that is later handed to
ceph_update_snap_trace() in the CEPH_CAP_OP_IMPORT case:
snaptrace = h + 1;
snaptrace_len = le32_to_cpu(h->snap_trace_len);
p = snaptrace + snaptrace_len;
...
case CEPH_CAP_OP_IMPORT:
if (snaptrace_len) {
...
if (ceph_update_snap_trace(mdsc, snaptrace,
snaptrace + snaptrace_len,
false, &realm)) { ... }
ceph_update_snap_trace() then decodes a struct ceph_mds_snap_realm
from snaptrace using ceph_decode_need(&p, e, sizeof(*ri), bad)
with the attacker-supplied fake end e == snaptrace + snaptrace_len.
With snaptrace_len == 0xFFFFFFFF the bound check is trivially
satisfied, ri = p reads sizeof(struct ceph_mds_snap_realm) past
the legitimate msg->front buffer, and ri->num_snaps /
ri->num_prior_parent_snaps then drive further out-of-bounds
reads of the encoded snap arrays.
The eleven msg_version >= 2 .. msg_version >= 12 decoder blocks
above the op switch each catch this OOB through their
ceph_decode_*_safe() / ceph_decode_need() helpers, but they sit
behind a hdr.version-gated if, so a malicious or compromised
MDS that sets msg->hdr.version = 1 reaches the IMPORT path with
no version-gated decoder having validated snap_trace_len. The
shape has been present since ceph_handle_caps() was introduced.
Validate snap_trace_len against the message front buffer before
consuming it, using the canonical ceph_decode_need() / ceph_has_room()
helper. The helper bounds the length with subtraction (n <= end - p,
guarded by end >= p) rather than pointer addition, so it is wrap-safe
for the attacker-controlled u32 length on 32-bit builds where
p + snap_trace_len could overflow the address space. This matches the
rest of the ceph decode path (e.g. the pool_ns_len check a few lines
below), and the existing goto bad cleanup already covers this exit
path.
Cc: stable@vger.kernel.org
Fixes: a8599bd821d0 ("ceph: capability management")
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
|
|
vfs_lookup_open() is a limited version of lookup_open() which is
exported for nfsd to use - to replace dentry_create().
It is limited in that no filename is given (thus no auditing) and no
LOOKUP_ flags are passed. A few "intent" LOOKUP flags are deduced from
the open flags.
If a non-regular file is found and appropriate error is returned and no
file is opened.
Signed-off-by: NeilBrown <neil@brown.name>
Link: https://patch.msgid.link/20260714230534.776886-4-neilb@ownmail.net
Reviewed-by: Jori Koolstra <jkoolstra@xs4all.nl>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
|
|
By moving this retry into lookup_open() we no longer need to pass around
the delegated_inode pointer.
Various variable assignments need to be moved out of the declaration
block so that they can be repeated after the "goto retry".
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jori Koolstra <jkoolstra@xs4all.nl>
Signed-off-by: NeilBrown <neil@brown.name>
Link: https://patch.msgid.link/20260714230534.776886-3-neilb@ownmail.net
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
|
|
The mnt_want_write() call and the parent inode locking in
open_last_lookups() are only needed for lookup_open(). So we can move
them and all the got_write handling into lookup_open().
Note that we need to also check create_error when determining whether to
unlock shared or not, as O_CREAT can be cleared, but create_error is
only set of O_CREAT was set.
The fsnotify calls come too as they must be in the locked region.
Also use the existing dir_inode uniformly for dir->d_inode.
This is a step towards exporting an better "open/create" interface to nfsd.
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jori Koolstra <jkoolstra@xs4all.nl>
Signed-off-by: NeilBrown <neil@brown.name>
Link: https://patch.msgid.link/20260714230534.776886-2-neilb@ownmail.net
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
|
|
Commit 319c15174757 ("epoll: take epitem list out of struct file")
intentionally removed temporary file references from the reverse path
check list. At the time, both epitems and their files were freed after
an RCU grace period, so unlist_file() could obtain file->f_lock through
an epitem while clear_tfile_check_list() held rcu_read_lock().
Commit 0ede61d8589c ("file: convert to SLAB_TYPESAFE_BY_RCU") made
struct file SLAB_TYPESAFE_BY_RCU and removed its RCU-delayed freeing.
RCU still protects the epitem, but no longer keeps the referenced file
from being freed and reused. A concurrent close can therefore make
unlist_file() lock or unlock f_lock in a recycled file object.
This violates the documented SLAB_TYPESAFE_BY_RCU rule requiring a
reference before acquiring an object's lock. The race was reproduced,
causing a wild unlock of f_lock in a recycled file and breaking its
mutual exclusion.
Add ->file to epitems_head to remember the pinned file independently of
->epitems. A concurrent EPOLL_CTL_DEL can empty ->epitems before the head
is unlisted, leaving no epi->ffd.file from which to drop the reference.
In list_file(), acquire the reference before adding the head to the
check list. The caller either owns a reference or holds the ep->mtx for
the epitem leading to the file. In the latter case, file_ref_get() can
fail after the last reference is dropped, but eventpoll_release_file()
must acquire the same mutex before the file can be freed. The dying leaf
can be skipped because removing links cannot increase the reverse path
count.
In unlist_file(), epnested_mutex excludes another list_file() or
unlist_file(), while head->next prevents a concurrent EPOLL_CTL_DEL from
freeing the head. Save head->file locally, clear it with head->next
under f_lock, and drop the reference after the RCU-protected operation.
Christian Brauner <brauner@kernel.org> quotes:
> SLAB_TYPESAFE_BY_RCU allows a slab slot to be reused while an RCU reader
> still holds its old address. Once that address contains a new live
> struct file, KASAN sees valid, unpoisoned memory and cannot distinguish
> the stale object identity. CONFIG_DEBUG_SPINLOCK exposes the failure
> instead.
>
> The failing interleaving is:
>
> CPU0: nested EPOLL_CTL_ADD CPU1: close/open churn
> ------------------------------------ ---------------------------------
> p = hlist_first_rcu(&head->epitems)
> epi = container_of(p, ...)
> close(victim)
> __fput()
> eventpoll_release_file()
> file_free(victim)
> // the slot is free; f_lock remains
> spin_lock(&epi->ffd.file->f_lock)
> open() reuses the slot as new_file
> spin_lock_init(&new_file->f_lock)
> spin_unlock(&epi->ffd.file->f_lock) // wild unlock of new_file's lock
>
> CONFIG_DEBUG_SPINLOCK reports:
>
> BUG: spinlock already unlocked on CPU#0, poc_unlist/150
> lock: 0xffff8880067fb200, .magic: dead4ead, .owner: <none>/-1, .owner_cpu: -1
> CPU: 0 UID: 1000 PID: 150 Comm: poc_unlist Not tainted 7.2.0-rc3-dirty #22 PREEMPTLAZY
> Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
> Call Trace:
> <TASK>
> dump_stack_lvl+0x64/0x80
> do_raw_spin_unlock+0x75/0xb0
> _raw_spin_unlock+0xe/0x30
> clear_tfile_check_list+0x88/0xe0
> do_epoll_ctl_file+0x519/0xcf0
> ? __pfx_ep_ptable_queue_proc+0x10/0x10
> do_epoll_ctl+0x8f/0x100
> __x64_sys_epoll_ctl+0x6f/0xa0
> do_syscall_64+0xdc/0x520
> ? srso_alias_return_thunk+0x5/0xfbef5
> entry_SYSCALL_64_after_hwframe+0x76/0x7e
> RIP: 0033:0x42034e
> Code: 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 e9 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007a657ff3c198 EFLAGS: 00000202 ORIG_RAX: 00000000000000e9
> RAX: ffffffffffffffda RBX: 00007a657ff3ccdc RCX: 000000000042034e
> RDX: 0000000000000003 RSI: 0000000000000001 RDI: 0000000000000004
> RBP: 00007a657ff3c2f0 R08: 0000000000000000 R09: 00007a657ff3c6c0
> R10: 00007a657ff3c1a4 R11: 0000000000000202 R12: 00007a657ff3c6c0
> R13: ffffffffffffffb8 R14: 000000000000000d R15: 00007fffb7de0210
> </TASK>
> ------------[ cut here ]------------
>
> unlist_file() does not appear as a separate frame because it was inlined
> into clear_tfile_check_list(). This report was obtained with mdelay()
> instrumentation immediately before spin_lock() and spin_unlock() in
> unlist_file() to widen the two race windows.
>
> More importantly, this is a wild unlock. The stale unlock can target
> f_lock of a different live file and invalidate mutual exclusion for
> state protected by that lock. Turning this into a reliable exploit
> would require precise scheduling and same-slot reuse and is likely
> difficult, but the primitive is potentially exploitable.
Reported-by: Qi Tang <tpluszz77@gmail.com>
Reported-by: Junxi Qian <qjx1298677004@gmail.com>
Fixes: 0ede61d8589c ("file: convert to SLAB_TYPESAFE_BY_RCU")
Cc: stable@vger.kernel.org
Signed-off-by: Guidong Han <2045gemini@gmail.com>
Link: https://patch.msgid.link/20260718104406.27897-1-2045gemini@gmail.com
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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Commit 0baad6f9b997 ("fs/super: skip non-memcg-aware nr_cached_objects
in memcg slab shrink") added a check in fs/super.c that skipped every
->nr_cached_objects() hook whenever the shrinker was invoked for a
non-root memcg, on the assumption that none of them honour sc->memcg.
That assumption is wrong for XFS, whose inode-reclaim hook is
intentionally driven from per-memcg contexts to free memcg-charged
slab. Encoding a blanket "never memcg-aware" policy in fs/super.c
short-circuits that path.
Push the check down into the callbacks whose counters really are
irrelevant to per-memcg reclaim - btrfs_nr_cached_objects() and
shmem_unused_huge_count() - and drop the fs/super.c gate. Each
filesystem can now lift the restriction independently if its counter
later grows memcg awareness, without touching fs/super.c.
Introduce mem_cgroup_shrink_is_root() in <linux/memcontrol.h> so the
callbacks don't open-code "sc->memcg is NULL or root".
Fixes: 0baad6f9b997 ("fs/super: skip non-memcg-aware nr_cached_objects in memcg slab shrink")
Acked-by: Qi Zheng <qi.zheng@linux.dev>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Link: https://patch.msgid.link/20260715103516.2410175-1-usama.arif@linux.dev
Acked-by: David Sterba <dsterba@suse.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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Fix afs_edit_dir_remove() to use afs_dir_get_block() to get block 0 rather
than afs_dir_find_block() as the latter caches the found block in the
afs_dir_iter and may[*] switch out the page it's on if another
afs_dir_find_block() is done. This parallels what afs_edit_dir_add() does.
[*] There's more than one block per page.
Fixes: a5b5beebcf96 ("afs: Use the contained hashtable to search a directory")
Closes: https://sashiko.dev/#/patchset/20260706153408.1231650-1-dhowells%40redhat.com
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://patch.msgid.link/2380759.1783956175@warthog.procyon.org.uk
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-fsdevel@vger.kernel.org
cc: stable@vger.kernel.org
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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Different io_private values indicate distinct completion contexts that
must not be merged together, as this could leak or corrupt the private
data associated with each ioend.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20260713074206.1768006-1-yi.zhang@huaweicloud.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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Zhang Yi <yi.zhang@huaweicloud.com> says:
This patch series contains a few trivial iomap-related fixes in
preparation for converting ext4 buffered I/O to use iomap.
The first three patches are taken from my ext4 conversion series [1], as
suggested by Christoph. The fourth patch fixes a bug originally reported
by Sashiko during review of my series; although unrelated to the ext4
conversion, it is worth fixing on its own. Please see the following
patches for detail. The fifth patch add comments for
ifs_clear/set_range_dirty(), and the last patch avoids merging ioends
that have different private data.
[1] https://lore.kernel.org/linux-ext4/20260511072344.191271-1-yi.zhang@huaweicloud.com/
* patches from https://patch.msgid.link/20260714082325.325163-1-yi.zhang@huaweicloud.com:
iomap: add comments for ifs_clear/set_range_dirty()
iomap: fix out-of-bounds bitmap_set() with zero-length range
iomap: fix incorrect did_zero setting in iomap_zero_iter()
iomap: support invalidating partial folios
iomap: correct the range of a partial dirty clear
Link: https://patch.msgid.link/20260714082325.325163-1-yi.zhang@huaweicloud.com
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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The range alignment strategy differs between ifs_clear_range_dirty() and
ifs_set_range_dirty(). The former rounds inwards to clear only
fully-covered blocks, while the latter rounds outwards to mark any
partially-touched block as dirty. Add comments to document this
asymmetry in block range calculation.
Suggested-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20260714082325.325163-6-yi.zhang@huaweicloud.com
Reviewed-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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ifs_set_range_dirty() and ifs_set_range_uptodate() compute last_blk
as (off + len - 1) >> i_blkbits. When off is 0 and len is 0, the
unsigned subtraction underflows to SIZE_MAX, producing a huge
last_blk and nr_blks value that causes bitmap_set() to write far
beyond the ifs->state allocation.
Regarding ifs_set_range_uptodate(), it is temporarily safe because len
cannot be passed in as 0. However, for ifs_set_range_dirty() this is
reachable from __iomap_write_end(): when copy_folio_from_iter_atomic()
returns 0 (e.g. user buffer fault) and the folio is already uptodate,
the guard at the top of __iomap_write_end() does not trigger because
!folio_test_uptodate() is false, and iomap_set_range_dirty() is called
with copied == 0.
Add a !len guard to both functions before the computation, so that a
zero-length range is a no-op.
Fixes: 4ce02c679722 ("iomap: Add per-block dirty state tracking to improve performance")
Cc: stable@vger.kernel.org # v6.6
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20260714082325.325163-5-yi.zhang@huaweicloud.com
Reviewed-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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The did_zero output parameter was unconditionally set after the loop,
which is incorrect. It should only be set when the zeroing operation
actually completes, not when IOMAP_F_STALE is set or when
IOMAP_F_FOLIO_BATCH is set but !folio causes the loop to break early,
or when iomap_iter_advance() returns an error.
This causes did_zero to be incorrectly set when zeroing a clean
unwritten extent because the loop exits early without actually zeroing
any data.
Fix it by using a local variable to track whether any folio was actually
zeroed, and only set did_zero after the loop if zeroing happened.
Fixes: 98eb8d95025b ("iomap: set did_zero to true when zeroing successfully")
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20260714082325.325163-4-yi.zhang@huaweicloud.com
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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Current iomap_invalidate_folio() can only invalidate an entire folio. If
we truncate a partial folio on a filesystem where the block size is
smaller than the folio size, it will leave behind dirty bits for the
truncated or punched blocks. During the write-back process, it will
attempt to map the invalid hole range. Fortunately, this has not caused
any real problems so far because the ->writeback_range() function
corrects the length.
However, the implementation of FALLOC_FL_ZERO_RANGE in ext4 depends on
the support for invalidating partial folios. When ext4 partially zeroes
out a dirty and unwritten folio, it does not perform a flush first like
XFS. Therefore, if the dirty bits of the corresponding area cannot be
cleared, the zeroed area after writeback remains in the written state
rather than reverting to the unwritten state. Fix this by supporting
invalidation of partial folios.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20260714082325.325163-3-yi.zhang@huaweicloud.com
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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The block range calculation in ifs_clear_range_dirty() is incorrect when
partially clearing a range in a folio. We cannot clear the dirty bit of
the first block or the last block if the start or end offset is not
blocksize-aligned. This has not yet caused any issues since we always
clear a whole folio in iomap_writeback_folio().
Fix this by rounding up the first block to blocksize alignment, and
calculate the last block by rounding down (using truncation). Correct
the nr_blks calculation accordingly.
Fixes: 4ce02c679722 ("iomap: Add per-block dirty state tracking to improve performance")
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20260714082325.325163-2-yi.zhang@huaweicloud.com
Reviewed-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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do_thaw_all() iterates over all superblocks via __iterate_supers()
with SUPER_ITER_EXCL, which acquires s_umount exclusively before
calling the callback and releases it afterwards. However, the
callback do_thaw_all_callback() calls thaw_super_locked() which
unconditionally releases s_umount on every code path. This results
in a second unlock attempt in __iterate_supers() that corrupts the
rwsem state, triggering a DEBUG_RWSEMS warning:
[ 182.601148] sysrq: Emergency Thaw of all frozen filesystems
[ 182.601865] ------------[ cut here ]------------
[ 182.602375] DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff99b1011e5870, owner = 0x0, curr 0xffff99b101b06c80, list not empty
[ 182.603817] WARNING: kernel/locking/rwsem.c:1412 at up_write+0xa3/0x170, CPU#2: kworker/2:1/53
[ 182.604578] Modules linked in:
[ 182.604864] CPU: 2 UID: 0 PID: 53 Comm: kworker/2:1 Not tainted 7.2.0-rc4-00001-gbd3bd93ea98a-dirty #4 PREEMPT(lazy)
[ 182.605711] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1kylin1 04/01/2014
[ 182.606417] Workqueue: events do_thaw_all
[ 182.606750] RIP: 0010:up_write+0xaf/0x170
[ 182.607076] Code: 19 3a 92 48 0f 44 c2 48 8b 55 08 48 8b 55 00 4c 8b 45 08 48 8b 55 00 48 8d 3d ad 91 e0 01 48 8b 4d 20 50 48 c7 c6 f0 8c 26 92 <67> 48 0f b9 3a e8 d7 93 4e 00 58 eb 81 48 83 7f 18 00 48 c7 c2 8d
[ 182.608563] RSP: 0018:ffffb670001d7e08 EFLAGS: 00010246
[ 182.609007] RAX: ffffffff92349e8d RBX: 0000000000000000 RCX: ffff99b1011e5870
[ 182.609595] RDX: 0000000000000000 RSI: ffffffff92268cf0 RDI: ffffffff92914d10
[ 182.610283] RBP: ffff99b1011e5870 R08: 0000000000000000 R09: ffff99b101b06c80
[ 182.610847] R10: ffff99b10139a808 R11: fefefefefefefeff R12: 0000000000000000
[ 182.611414] R13: ffffffff90cf74d0 R14: 0000000000000000 R15: ffff99b1011e5800
[ 182.612009] FS: 0000000000000000(0000) GS:ffff99b1eaaee000(0000) knlGS:0000000000000000
[ 182.612670] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 182.613146] CR2: 00000000005c631c CR3: 00000000013ee000 CR4: 00000000000006f0
[ 182.613722] Call Trace:
[ 182.613946] <TASK>
[ 182.614130] __iterate_supers+0x128/0x150
[ 182.614463] do_thaw_all+0x1b/0x30
[ 182.614759] process_scheduled_works+0xbb/0x3f0
[ 182.615150] ? __pfx_worker_thread+0x10/0x10
[ 182.615499] worker_thread+0x129/0x270
[ 182.615816] ? __pfx_worker_thread+0x10/0x10
[ 182.616201] kthread+0xe2/0x120
[ 182.616469] ? __pfx_kthread+0x10/0x10
[ 182.616792] ret_from_fork+0x15b/0x240
[ 182.617115] ? __pfx_kthread+0x10/0x10
[ 182.617426] ret_from_fork_asm+0x1a/0x30
[ 182.617761] </TASK>
[ 182.617968] ---[ end trace 0000000000000000 ]---
[ 182.618412] Emergency Thaw complete
Fix this by switching to SUPER_ITER_UNLOCKED and acquiring s_umount
in the callback via super_lock_excl() before calling
thaw_super_locked(). This matches the locking pattern expected by
thaw_super_locked() and eliminates the double unlock.
While at it, remove the dead 'return;' at the end of
do_thaw_all_callback().
Fixes: 2992476528ae ("super: use a common iterator (Part 1)")
Cc: stable@vger.kernel.org
Signed-off-by: Chen Changcheng <chenchangcheng@kylinos.cn>
Link: https://patch.msgid.link/20260721064140.152305-1-chenchangcheng@kylinos.cn
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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