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2026-07-20fscrypt: Always use blk-crypto for contents on block-based filesystemsEric Biggers
For encrypting and decrypting file contents on block-based filesystems (i.e., ext4 and f2fs, but not ceph and ubifs), always use blk-crypto instead of fs-layer crypto (direct use of crypto_skcipher). Since the blk-crypto API provides a fallback to CPU-based encryption, it's all that's needed on block-based filesystems. The support for two alternative block-based file contents encryption implementations, fs-layer and blk-crypto, existed mainly for historical reasons, as the fs-layer path came first. Some of it is also still needed for the non-block-based filesystems, but a lot of it isn't. Removing the duplicate fs-layer code paths greatly simplifies the code, most of which is done in later commits. Specific implementation details: - SB_INLINECRYPT now controls whether blk_crypto_config::allow_hw is set to true, instead of whether blk-crypto is used at all. The effect is that the semantics are preserved: the inlinecrypt mount option selects the use of inline encryption hardware instead of the CPU. - Set up a blk_crypto_key iff the file is a regular file on a block-based filesystem. To determine whether the filesystem is block-based, add a bit fscrypt_operations::is_block_based. - Remove fscrypt_select_encryption_impl(). Move the logging logic that was previously there into fscrypt_prepare_inline_crypt_key(). Note that blk_crypto_config_supported() is no longer needed. Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20260713023708.9245-6-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-07-20fscrypt: Fully disallow IV_INO_LBLK_32 with s_blocksize != PAGE_SIZEEric Biggers
FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32 with s_blocksize != PAGE_SIZE works only with the fs-layer implementation of file contents encryption, not blk-crypto. This is a problem for standardizing on blk-crypto. Fortunately, no one should be using this combination anyway. It doesn't make sense because the entire point of IV_INO_LBLK_32 is to support inline encryption hardware that is limited to 32-bit DUNs. Thus, fully disallow IV_INO_LBLK_32 with s_blocksize != PAGE_SIZE. Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20260713023708.9245-5-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-07-20blk-crypto: Allow control over whether hardware is usedEric Biggers
fscrypt uses inline encryption hardware only when the "inlinecrypt" mount option is given. I'd like to keep that behavior even after standardizing on the blk-crypto API for file contents encryption. That is, the default should continue to be the well-tested CPU-based encryption code, and the use of inline encryption hardware should continue to be an opt-in feature for systems where it's beneficial and has been fully validated (including verifying ciphertext correctness). To support this use case, extend blk_crypto_config with a new flag BLK_CRYPTO_CFG_ALLOW_HW. For now it's always set. Later commits will change that. Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20260713023708.9245-4-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-07-20fscrypt: Remove workaround for bug in gcc 7 and earlierEric Biggers
Since the kernel's minimum gcc version is now 8.1, the workaround for a strange gcc bug in fscrypt_ioctl_set_policy() is no longer needed. Link: https://patch.msgid.link/20260619051008.51223-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-07-20fscrypt: Simplify handling of errors during initcallEric Biggers
Since CONFIG_FS_ENCRYPTION is a bool, not a tristate, fs/crypto/ can only be builtin or absent entirely; it can't be a loadable module. Therefore, the error code that gets returned from the fscrypt_init() initcall is never used. If any part of the initcall does fail, which should never happen, the kernel will be left in a bad state. Following the usual convention for builtin code, just panic the kernel if any of part of the initcall fails. This simplifies the code. This closely mirrors commit e77000ccc531 ("fsverity: simplify handling of errors during initcall"). Link: https://patch.msgid.link/20260619000030.166851-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-07-20fscrypt: Remove FSCRYPT_MODE_MAXEric Biggers
Now that the arrays of per-mode keys in struct fscrypt_master_key have been replaced by a linked list, the definition of FSCRYPT_MODE_MAX doesn't do anything useful. (Previously it was used to size these arrays.) Remove it. Link: https://patch.msgid.link/20260618231404.132829-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-07-20fscrypt: Avoid dynamic allocation in fscrypt_get_devices()Eric Biggers
When a blk_crypto_key starts being used or is evicted, fs/crypto/ calls fscrypt_get_devices() to get the filesystem's list of block devices, then iterates over them and calls blk_crypto_config_supported(), blk_crypto_start_using_key(), or blk_crypto_evict_key() on each one. Currently, the block device pointers are placed in a dynamically allocated array. This dynamic allocation is problematic because: - It can fail, especially at the fscrypt_destroy_inline_crypt_key() call site when it's invoked for inode eviction under direct reclaim. - fscrypt_destroy_inline_crypt_key() doesn't handle the failure. It just zeroizes and frees the blk_crypto_key without calling blk_crypto_evict_key(). That causes a use-after-free. For now, let's fix this in the straightforward and easily-backportable way by switching to an on-stack array. Currently the fscrypt multi-device functionality is used only by f2fs, which has a hardcoded limit of 8 block devices. An on-stack array works fine for that. (Of course, this solution won't scale up to large number of block devices. For that we'd need a different solution, like moving the block device iteration into the filesystem. Or in the case of btrfs, which will only support blk-crypto-fallback, we should make it just call blk-crypto-fallback directly, so the block devices won't be needed.) Fixes: 22e9947a4b2b ("fscrypt: stop holding extra request_queue references") Cc: stable@vger.kernel.org Reported-by: Sashiko <sashiko-bot@kernel.org> Closes: https://sashiko.dev/#/patchset/20260713023708.9245-1-ebiggers%40kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20260719055602.78828-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-07-20fscrypt: Use lock guards for mutexesEric Biggers
Replace all remaining calls to mutex_lock() and mutex_unlock() in fs/crypto/ with lock guards. No functional change. Link: https://patch.msgid.link/20260618184852.3469301-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-07-20fscrypt: Add missing superblock check in find_or_insert_direct_key()Eric Biggers
The legacy 'fscrypt_direct_keys' table caches master keys that are used by v1 encryption policies that have FSCRYPT_POLICY_FLAG_DIRECT_KEY. It's just a global table for all filesystems (since the keys can be provided by the legacy process-subscribed keyrings mechanism, which makes it difficult to reuse super_block::s_master_keys). The entries in it ('struct fscrypt_direct_key') do contain a super_block pointer, though, for passing to fscrypt_destroy_inline_crypt_key() when the last inode that references the key is evicted. However, when finding the fscrypt_direct_key for an inode, we weren't actually comparing the super_block pointer. As a result, inodes with different super_blocks could point to the same fscrypt_direct_key. That could extend the lifetime of a fscrypt_direct_key beyond the super_block it points to, causing a use-after-free later. Fix this by creating distinct fscrypt_direct_key structs for distinct super_block structs. Note that this problem doesn't exist in the v2 policy equivalent ("per-mode keys"), since the data structures there are per super_block. Fixes: 22e9947a4b2b ("fscrypt: stop holding extra request_queue references") Cc: stable@vger.kernel.org Reported-by: Sashiko <sashiko-bot@kernel.org> Closes: https://sashiko.dev/#/patchset/20260717044303.425265-1-ebiggers%40kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20260719033120.122120-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-07-20NFS: Decrement refcounts if allocating nfs_free_stateid_data failsAnna Schumaker
I noticed that we were immediately exiting this function if the allocation fails, leaving the client and server object refcounts bumped. Fix this by creating a common exit point to clean up dangling references. Fixes: 576acc259146 ("nfs4: take a reference on the nfs_client when running FREE_STATEID") Signed-off-by: Anna Schumaker <anna.schumaker@hammerspace.com>
2026-07-20NFS: Pin the 'struct nfs_server' during a FREE_STATEID callAnna Schumaker
Dan Aloni reports that he was able to hit a use-after-free bug if a FREE_STATEID operation gets delayed for whatever reason. Fix this by bumping the refcount of the 'struct nfs_server' object for the duration of the FREE_STATEID so it doesn't get cleaned up from underneath us while operations are still in flight. Reported-by: Dan Aloni <dan.aloni@vastdata.com> Fixes: 7c1d5fae4a87 ("NFSv4: Convert nfs41_free_stateid to use an asynchronous RPC call") Tested-by: Dan Aloni <dan.aloni@vastdata.com> Signed-off-by: Anna Schumaker <anna.schumaker@hammerspace.com>
2026-07-20xfs: propagate errors from xfs_rtginode_loadGuanghui Yang
xfs_rtginode_ensure() treats every xfs_rtginode_load() error other than -ENOENT as success. This can leave the realtime group inode unset after an I/O, allocation, or corruption error. Growfs then continues as though the inode had been loaded. Only -ENOENT means that the inode needs to be created. Return all other errors to the growfs caller. Fixes: ae897e0bed0f ("xfs: support creating per-RTG files in growfs") Cc: stable@vger.kernel.org Signed-off-by: Guanghui Yang <3497809730@qq.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2026-07-19smb: client: bound dirent name against end of SMB response in cifs_filldirJay Vadayath
cifs_filldir() copies the entry name out of an SMB1 TRANS2_FIND_FIRST / FIND_NEXT response using a length (de.namelen) supplied by the server. The kmalloc'd SMB response buffer is bounded, but nothing checks that de.name + de.namelen still lies inside that buffer before the eventual filldir64() -> verify_dirent_name() -> memchr() reads namelen bytes. A hostile SMB1 server that returns an oversized FileNameLength in a directory entry therefore causes memchr() to read past the end of the response slab buffer. Reachable from any user who can list a directory on a CIFS mount served by an attacker-controlled server (getdents64() on the mounted directory): BUG: KASAN: slab-out-of-bounds in memchr+0x71/0x80 Read of size 1 at addr ffff88800e0640cc by task poc/115 Call Trace: dump_stack_lvl+0x64/0x80 print_report+0xce/0x620 kasan_report+0xec/0x120 memchr+0x71/0x80 filldir64+0x4c/0x6a0 cifs_filldir.constprop.0+0x9bb/0x1e00 cifs_readdir+0x2101/0x3380 iterate_dir+0x19c/0x520 __x64_sys_getdents64+0x126/0x210 do_syscall_64+0x107/0x5a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Pass the end-of-response pointer down to cifs_filldir() and reject entries whose name would extend past that boundary. This bug was discovered by Artiphishell's vTriage pipeline, which generated a userspace reproducer (an emulated hostile SMB1 server plus a getdents64() client) that reliably triggers the KASAN report on an unpatched kernel. The fix below was drafted with the Claude coding assistant; a userspace reproducer is available on request. Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Jay Vadayath <jay@artiphishell.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-07-19smb: client: validate DFS referral PathConsumedYichong Chen
parse_dfs_referrals() validates that the response contains the fixed referral entry array and, on for-next, the per-referral string offsets. However, the response also contains a PathConsumed value that is later used for DFS path parsing. If a malformed response provides a PathConsumed value larger than the search name, later DFS parsing can advance beyond the end of the path. Validate PathConsumed against the search name length before storing it in the parsed referral. Fixes: 4ecce920e13a ("CIFS: move DFS response parsing out of SMB1 code") Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Signed-off-by: Yichong Chen <chenyichong@uniontech.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-07-19gfs2: Remove the glock lru list and shrinkerAndreas Gruenbacher
We are no longer keeping unreferences glocks around, so remove the now-obsolete glock lru list and shrinker. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2026-07-19gfs2: Skip dlm unlocks earlierAndreas Gruenbacher
When we were still caching unreferenced glocks, evicting all the cached inodes in gfs2_kill_sb() did put the unreferenced glocks onto the glock lru list, and they would be freed in gfs2_gl_hash_clear(). We could set the SDF_SKIP_DLM_UNLOCK flag in gfs2_gl_hash_clear() to indicate to gdlm_put_lock() to skip unlocking glocks explicitly when possible. Now, glocks are demoted and dropped immediately though, so to allow gdlm_put_lock() to skip unnecessary unlocking, we need to set some "unmount" flag before calling gfs2_evict_inodes(). We can use the existing SDF_KILL flag for that if we set it before calling gfs2_evict_inodes() in gfs2_kill_sb(). Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2026-07-19gfs2: Don't cache unreferenced glocksAndreas Gruenbacher
Currently, gfs2 caches unreferenced glocks until memory pressure sets in or the filesystem is unmounted. This was supposedly done to avoid excessive log flushing: when a glock still has outstanding revokes, freeing it requires an extra log flush, and we want to avoid too many of those extra log flushes. Since commit 9287c6452d2b1 ("gfs2: Fix occasional glock use-after-free"), outstanding revokes are accounted for in the glock reference count and glocks with outstanding revokes will never be freed anymore, so this is no longer an issue. This also means that we won't need a glock LRU list anymore, but we leave removing that list to a later patch for better readability. It might seem that glocks that are not referenced anymore can be dropped immediately without unlocking them first, but that isn't true for inode glocks that have an address space attached (the "gfs2_glock(aspace)" slab cache): that address space is only truncated when the associated glock is unlocked. So unlock those glocks when they become unreferenced. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2026-07-19gfs2: Enable automatic glock hash table shrinkingAndreas Gruenbacher
All of the examiner functions passed to glock_hash_walk() can deal with glock hash table resizes and the resulting repeat visiting of glocks, so we can allow automatic glock hash table shrinking. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2026-07-18debugfs: warn if file creation failed due to uninitialized debugfsYohei Kojima
Improve debugfs_start_creating() to warn if it was used before debugfs initialization. It silently returned ERR_PTR(-ENOENT) before, but it is hard to find the cause of failure especially if it was called by debugfs_create_dir(), because the document of the function says: > NOTE: it's expected that most callers should _ignore_ the errors returned > by this function. Other debugfs functions handle the fact that the "dentry" > passed to them could be an error and they don't crash in that case. > Drivers should generally work fine even if debugfs fails to init anyway. Signed-off-by: Yohei Kojima <yk@y-koj.net> Link: https://patch.msgid.link/6d1dc775f7d5e754d734907514534054f682bac5.1781171918.git.yk@y-koj.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-07-18kernfs: Replace strcpy(s, "../") with memcpy(s, "../", 4)David Laight
The code has already checked there is enough room. Use memcpy() to avoid compiler warnings from possibly unbounded strcpy(). Signed-off-by: David Laight <david.laight.linux@gmail.com> Link: https://patch.msgid.link/20260606202633.5018-6-david.laight.linux@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-07-18kernfs: simplify kernfs_name_hash()Dmitry Antipov
In 'kernfs_name_hash()', 'name' is NUL-terminated so it may be directly scanned up to end without an extra call to 'strlen()'. Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru> Link: https://patch.msgid.link/20260617073941.472337-1-dmantipov@yandex.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-07-17Merge tag 'v7.2-rc3-smb3-server-fixes' of git://git.samba.org/ksmbdLinus Torvalds
Pull smb server fixes from Steve French: "ksmbd server fixes, mostly addressing malformed SMB request handling and connection/session lifetime issues, including two information-disclosure or memory-safety bugs in the SMB2 request/response paths. - validate FILE_ALLOCATION_INFORMATION before block rounding to prevent a client-controlled overflow from truncating a file. - pin connections while asynchronous oplock and lease-break notifications are pending. - initialize compound SMB2 READ alignment padding, preventing disclosure of uninitialized heap bytes. - release the allocated alternate-stream xattr name after rename. - size multichannel binding session-key buffers for the largest permitted key, avoiding a stack buffer overflow. - remove a disconnecting connection's channels from every session, including channels whose binding state has since changed. - serialize binding preauthentication-session lookup and update against its teardown. - check that every compound request element contains StructureSize2 before reading it" * tag 'v7.2-rc3-smb3-server-fixes' of git://git.samba.org/ksmbd: ksmbd: validate compound request size before reading StructureSize2 ksmbd: lock the binding preauth session in smb3_preauth_hash_rsp ksmbd: remove stale channels from all sessions on teardown ksmbd: fix stack buffer overflow in multichannel session-key copy ksmbd: fix memory leak of xattr_stream_name in smb2_rename() ksmbd: zero the smb2_read alignment tail to avoid an infoleak ksmbd: pin conn during async oplock break notification ksmbd: fix integer overflow in set_file_allocation_info()
2026-07-18ntfs: preserve RECALL_ON_OPEN on WSL special-file reparse pointsNamjae Jeon
When creating a WSL special file (socket, fifo, character or block device), __ntfs_create() sets FILE_ATTRIBUTE_RECALL_ON_OPEN in ni->flags as valid_reparse_data() requires for these tags. This flag is intentionally absent from $FILE_NAME, so the subsequent reload ni->flags = fn->file_attributes; drops it from ni->flags, the authoritative copy written back to $STANDARD_INFORMATION. The on-disk file_attributes becomes 0x00000404 instead of 0x00040404, and after a remount valid_reparse_data() rejects the reparse point while fsck reports "$REPARSE_POINT data is corrupted". Preserve the RECALL_ON_OPEN bit across the reload. Symlinks do not set that bit, so they are unaffected. Fixes: af0db57d4293 ("ntfs: update inode operations") Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-07-17ecryptfs: hold msg ctx list lock when cleaning daemon queueYichong Chen
ecryptfs_exorcise_daemon() drops queued messages from a dying daemon without holding ecryptfs_msg_ctx_lists_mux, but ecryptfs_msg_ctx_alloc_to_free() requires that lock. Take the list lock while moving the queued contexts back to the free list to avoid racing with other global msg ctx list users. Fixes: f66e883eb618 ("eCryptfs: integrate eCryptfs device handle into the module.") Cc: <stable@vger.kernel.org> Signed-off-by: Yichong Chen <chenyichong@uniontech.com> Signed-off-by: Tyler Hicks <code@tyhicks.com>
2026-07-17ecryptfs: release message context on send failureYichong Chen
ecryptfs_send_message_locked() moves a message context from the free list to the allocated list before sending the request to the userspace daemon. If ecryptfs_send_miscdev() fails, the context is left on the allocated list and cannot be reused. Move it back to the free list on failure and clear the caller's pointer. Fixes: f66e883eb618 ("eCryptfs: integrate eCryptfs device handle into the module.") Cc: <stable@vger.kernel.org> Signed-off-by: Yichong Chen <chenyichong@uniontech.com> Signed-off-by: Tyler Hicks <code@tyhicks.com>
2026-07-17ecryptfs: reject oversized encrypted_key_size in parse_tag_3_packetHanQuan
parse_tag_3_packet() set encrypted_key_size from the Tag 3 packet body without bounding it against ECRYPTFS_MAX_KEY_BYTES (64). When encrypted_key_size > 64, decrypt_passphrase_encrypted_session_key() sets decrypted_key_size = encrypted_key_size and performs two out-of-bounds writes: 1. crypto_skcipher_decrypt() writes encrypted_key_size bytes into decrypted_key[64] via scatterlist, overflowing into the parent ecryptfs_auth_tok struct. 2. memcpy(crypt_stat->key, decrypted_key, decrypted_key_size) writes into crypt_stat->key[64], corrupting root_iv, keysig_list, and mutexes in ecryptfs_crypt_stat. Only AES-192 (cipher code 0x08) enables this because it sets crypt_stat->key_size = 24 independently of encrypted_key_size, allowing crypto_skcipher_setkey() to succeed while encrypted_key_size exceeds ECRYPTFS_MAX_KEY_BYTES. The PKI decryption path (parse_tag_65_packet) already validates decrypted_key_size <= ECRYPTFS_MAX_KEY_BYTES; the passphrase path omits this check. Bound encrypted_key_size against ECRYPTFS_MAX_KEY_BYTES (64) rather than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES (512). The 64-byte limit also protects the 512-byte encrypted_key[] buffer, so the former 512-byte check is removed as redundant. Fixes: 237fead61998 ("[PATCH] ecryptfs: fs/Makefile and fs/Kconfig") Cc: <stable@vger.kernel.org> Signed-off-by: HanQuan <eilaimemedsnaimel@gmail.com> [tyhicks: Adjust the code comment to refer to macros representing the buffer sizes rather than mentioning the buffer size values since they may change in the future] Signed-off-by: Tyler Hicks <code@tyhicks.com>
2026-07-17lockd: fix NLMv3 GRANTED_MSG handlingOlga Kornievskaia
GRANTED_MSG is a server-to-client callback, so it runs on the client, where nfsd never registers nlmsvc_ops. The nlm3svc_lookup_host() helper is for the server-side request handlers (TEST/LOCK/CANCEL/UNLOCK), which reach nlmsvc_ops->fopen and must reject requests when nfsd isn't running. GRANTED_MSG only calls nlmclnt_grant(). Instead, of calling nlm3svc_lookup_host(), which results in a client failing a GRANTED_MSG call, call nlmsvc_lookup_host(). Fixes: 6c534ad999b6 ("lockd: Use xdrgen XDR functions for the NLMv3 GRANTED_MSG procedure") Cc: stable@vger.kernel.org Signed-off-by: Olga Kornievskaia <okorniev@redhat.com> Reviewed-by: NeilBrown <neil@brown.name> Link: https://patch.msgid.link/20260625211852.31972-1-okorniev@redhat.com Signed-off-by: Chuck Lever <cel@kernel.org>
2026-07-17fuse: allow larger read requests by setting bdi->io_pagesJim Harris
A FUSE server that advertises a large max_pages and max_write (e.g. max_pages=256, max_write=1MB) cannot currently obtain matching FUSE_READ request sizes from the kernel. Buffered sequential writes arrive at the server at the negotiated max_write size, but a large buffered read() is split into several smaller FUSE_READ requests. For a buffered read, filemap_get_pages() -> page_cache_sync_ra() sizes the read against ractl_max_pages(): max_pages = ractl->ra->ra_pages; if (req_size > max_pages && bdi->io_pages > max_pages) max_pages = min(req_size, bdi->io_pages); fuse leaves bdi->io_pages at the default VM_READAHEAD_PAGES (128KB), so a 1MB read() (req_size = 256 pages) is clamped to the readahead window (128KB, or 256KB for POSIX_FADV_SEQUENTIAL), producing four 256KB FUSE_READ round-trips instead of one. Set bdi->io_pages to fc->max_pages after feature negotiation. As the code above shows, io_pages only raises the limit when the request size already exceeds the readahead window, so it enlarges explicitly requested reads without enlarging the speculative readahead window. This avoids increasing speculative page-cache readahead on behalf of an unprivileged server. NFS does the same, setting io_pages from rpages while leaving ra_pages at the default. fc->max_pages is already bounded by fc->max_pages_limit (and, for virtio-fs, by the virtqueue descriptor count), so io_pages inherits the same bound. Suggested-by: Joanne Koong <joannelkoong@gmail.com> Signed-off-by: Jim Harris <jim.harris@nvidia.com> Assisted-by: Cursor:claude-opus-4.8 Reviewed-by: Joanne Koong <joannelkoong@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-07-17UDF symlink pathComponent header OOB readDavid Lee
udf_symlink_filler() can enter udf_pc_to_char() with a partial pathComponent header. Validate that enough input remains for a complete pathComponent header before accessing it. Reject malformed symlink data that would otherwise make udf_pc_to_char() perform an out-of-bounds read. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: David Lee <david.lee@trailofbits.com> Assisted-by: Codex:gpt-5.5 Link: https://patch.msgid.link/20260717104722.41446-1-david.lee@trailofbits.com Signed-off-by: Jan Kara <jack@suse.cz>
2026-07-17fuse: publish io-uring queues with release semanticsJoanne Koong
fuse_uring_create_queue() initializes a fuse_ring_queue and then publishes the pointer into ring->queues[qid] with WRITE_ONCE() under the fch->lock. There are several readers that may concurrently be fetching that pointer locklessly and then deferencing it. WRITE_ONCE() doesn't ensure ordering of the queue's field initialization before the ring->queues[qid] pointer assignment. The queue must be published with smp_store_release() so the field initialization is guaranteed to happen before. Readers in paths where the read may happen concurrently with the store need to use READ_ONCE() because any race involving a plain access is undefined. Fixes: 24fe962c86f5 ("fuse: {io-uring} Handle SQEs - register commands") Cc: stable@vger.kernel.org Reviewed-by: Bernd Schubert <bernd@bsbernd.com> Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-07-17fuse: use release/acquire for fch->initializedJoanne Koong
fuse_chan_set_initialized() sets values for the connection state and then sets fch->initialized to true, but lockless readers read fch->initialized and if true, go to read the connection state values, without using any barriers. There are a few instances where this happens (fuse_uring_cmd() before dispatching register / commit-and-fetch cmds, fuse_dev_do_wriite() for handling notify retrieves, etc). To make this as simple as possible, use release/acquire semantics for writing/reading fch->initialized. Add the missing read barriers. This is not marked for stable as these are not realistically reachable on a well-behaved server, and buggy/malicious servers who trigger this path fail benignly rather than crash or deadlock the kernel. Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-07-17fuse: fix missing barrier when checking io-uring readinessJoanne Koong
fuse_block_alloc() reads fch->initialized and then fch->io_uring. fch->io_uring is set before fch->initialized, ordered by the smp_wmb() in fuse_chan_set_intialized(), but fuse_block_alloc() has no matching read barrier between the two loads. This may lead a CPU to observe fch->initialized=1 but fch->io_uring=0, and skip the check that blocks request allocation until the io-uring queues are ready. This can reintroduce the lock-order inversion deadlock that commit 3393ff964e0f prevents. Add an smp_rmb() barrier to pair with the smp_wmb() in fuse_chan_set_initialized() to prevent this. Fixes: 3393ff964e0f ("fuse: block request allocation until io-uring init is complete") Cc: stable@vger.kernel.org Reviewed-by: Bernd Schubert <bernd@bsbernd.com> Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-07-16Merge tag 'v7.2-rc3-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds
Pull smb client fixes from Steve French: - fallocate fixes - unit test fixes - fix allocation size after duplicate extents - fix check for overlapping data areas * tag 'v7.2-rc3-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6: smb/client: flush dirty data before punching a hole smb/client: Use EXPORT_SYMBOL_IF_KUNIT() to export symbols in SMB2 smb/client: Use EXPORT_SYMBOL_IF_KUNIT() to export symbols smb: client: reject overlapping data areas in SMB2 responses smb/client: refresh allocation after EOF-extending fallocate smb/client: emulate small EOF-extending mode 0 fallocate ranges smb/client: reduce fallocate zero buffer allocation smb/client: handle overlapping allocated ranges in fallocate smb/client: refresh allocation size after duplicate extents smb: client: use kvzalloc() for megabyte buffer in simple fallocate
2026-07-16Merge tag 'xfs-fixes-7.2-rc4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds
Pull xfs fixes from Carlos Maiolino: "This contains mostly a series of bug fixes found by different LLM models" * tag 'xfs-fixes-7.2-rc4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (21 commits) xfs: don't zap bmbt forks if they are MAXLEVELS tall xfs: clamp timestamp nanoseconds correctly xfs: fully check the parent handle when it points to the rootdir xfs: handle non-inode owners for rtrmap record checking xfs: fix off-by-one error when calling xchk_xref_has_rt_owner xfs: set xfarray killable sort correctly xfs: grab rtrmap btree when checking rgsuper xfs: write the rg superblock when fixing it xfs: use the rt version of the cow staging checker xfs: use rtrefcount btree cursor in xchk_xref_is_rt_cow_staging xfs: don't wrap around quota ids in dqiterate xfs: move cow_replace_mapping to xfs_bmap_util.c xfs: make cow repair somewhat flaky when debugging knob enabled xfs: don't replace the wrong part of the cow fork xfs: resample the data fork mapping after cycling ILOCK xfs: fix null pointer dereference in tracepoint xfs: use xfs_csn_t for xlog_cil_push_now() push_seq parameter xfs: tie zoned sysfs lifetime to zone info xfs: fail recovery on a committed log item with no regions xfs: splice unsorted log items back to the transaction after the loop ...
2026-07-16Merge tag 'erofs-for-7.2-rc4-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs Pull erofs fixes from Gao Xiang: - Fix sanity checks for ztailpacking tail pclusters to avoid false corruption reports - Use more informative s_id for file-backed mounts - Hide the meaningless "cache_strategy=" mount option on plain (uncompressed) filesystems - Remove the unneeded erofs_is_ishare_inode() helper * tag 'erofs-for-7.2-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs: erofs: hide "cache_strategy=" for plain filesystems erofs: get rid of erofs_is_ishare_inode() helper erofs: relax sanity check for tail pclusters due to ztailpacking erofs: use more informative s_id for file-backed mounts
2026-07-16ksmbd: validate compound request size before reading StructureSize2Xiang Mei (Microsoft)
When ksmbd validates a compound (chained) SMB2 request, ksmbd_smb2_check_message() reads pdu->StructureSize2 without first checking that the compound element is large enough to contain it. StructureSize2 is a 2-byte field at offset 64 (__SMB2_HEADER_STRUCTURE_SIZE) from the start of each element. The compound-walking logic only guarantees that a full 64-byte SMB2 header is present for the trailing element: when NextCommand is 0, len is reduced to the number of bytes remaining after next_smb2_rcv_hdr_off. A remote client can craft a compound request whose last element has exactly 64 bytes, so the 2-byte StructureSize2 read at offset 64 extends one byte past the receive buffer, producing a slab-out-of-bounds read. BUG: KASAN: slab-out-of-bounds in ksmbd_smb2_check_message (fs/smb/server/smb2misc.c:402) Read of size 2 at addr ffff888012ae31ac by task kworker/0:1/14 The buggy address is located 172 bytes inside of allocated 173-byte region Workqueue: ksmbd-io handle_ksmbd_work Call Trace: ... kasan_report (mm/kasan/report.c:595) ksmbd_smb2_check_message (fs/smb/server/smb2misc.c:402) handle_ksmbd_work (fs/smb/server/server.c:119) process_one_work (kernel/workqueue.c:3314) worker_thread (kernel/workqueue.c:3397) kthread (kernel/kthread.c:436) ret_from_fork (arch/x86/kernel/process.c:158) ret_from_fork_asm (arch/x86/entry/entry_64.S:245) Reject any compound element that is too small to hold StructureSize2 before dereferencing it. Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Reported-by: AutonomousCodeSecurity@microsoft.com Signed-off-by: Xiang Mei (Microsoft) <xmei5@asu.edu> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-07-16ksmbd: lock the binding preauth session in smb3_preauth_hash_rspGil Portnoy
smb3_preauth_hash_rsp() computes the SMB3.1.1 preauth integrity hash on the response path. For a binding SESSION_SETUP it looks up the per-connection preauth_session and reads its Preauth_HashValue. smb2_sess_setup() frees that preauth_session under ksmbd_conn_lock(). Two SMB2 requests on one connection can run concurrently, so an unlocked lookup and hash can use a preauth_session after another worker frees it. Take ksmbd_conn_lock() before selecting conn->binding and hold it across the selected preauth hash lookup and update. This preserves the existing hash selection while preventing the lookup-to-use lifetime race. Fixes: 1c5daa2ea924 ("ksmbd: handle channel binding with a different user") Signed-off-by: Gil Portnoy <dddhkts1@gmail.com> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-07-16ksmbd: remove stale channels from all sessions on teardownGil Portnoy
ksmbd_sessions_deregister() removes a connection's channels from other sessions' channel lists only while conn->binding is still set: if (conn->binding) { hash_for_each_safe(sessions_table, ...) ksmbd_chann_del(conn, sess); } conn->binding is a transient flag: it is cleared once a binding SESSION_SETUP completes, and also by a subsequent non-binding SESSION_SETUP on the same connection (a reauthentication on a bound channel, or a new SessionId==0 setup). A connection that has bound a channel into another session's ksmbd_chann_list and then clears conn->binding leaves that channel behind when it disconnects: the channel, whose chann->conn points at the now freed struct ksmbd_conn, stays on the owner session's list. When the owning connection later tears down, the second loop dereferences the stale channel: xa_for_each(&sess->ksmbd_chann_list, chann_id, chann) if (chann->conn != conn) ksmbd_conn_set_exiting(chann->conn); /* freed */ which is a use-after-free write into the freed ksmbd_conn (the same stale channel is also walked by show_proc_session() through /proc). The session is leaked as well, because its channel list never empties. Remove the conn->binding gate so a connection always removes its channels from every session on teardown. Fixes: faf8578c77f3 ("ksmbd: find bound sessions during reauthentication") Signed-off-by: Gil Portnoy <dddhkts1@gmail.com> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-07-16ksmbd: fix stack buffer overflow in multichannel session-key copyGil Portnoy
Commit 4b706360ffb7 ("ksmbd: fix multichannel binding and enforce channel limit") moved the binding-path session key out of the session-wide sess->sess_key (CIFS_KEY_SIZE = 40) into a new per-channel buffer, and sized both that buffer and the on-stack copy used during binding with SMB2_NTLMV2_SESSKEY_SIZE (16): struct channel { char sess_key[SMB2_NTLMV2_SESSKEY_SIZE]; /* 16 */ ... }; ntlm_authenticate() / krb5_authenticate(): char channel_key[SMB2_NTLMV2_SESSKEY_SIZE] = {}; /* 16 */ char *auth_key = conn->binding ? channel_key : sess->sess_key; The two writers that fill this destination still bound the copy length against CIFS_KEY_SIZE (40), not against the 16-byte buffer: ksmbd_decode_ntlmssp_auth_blob() (NTLM key exchange): if (sess_key_len > CIFS_KEY_SIZE) /* 40 */ return -EINVAL; arc4_crypt(ctx_arc4, sess_key, (char *)authblob + sess_key_off, sess_key_len); ksmbd_krb5_authenticate(): if (resp->session_key_len > sizeof(sess->sess_key)) /* 40 */ ... memcpy(sess_key, resp->payload, resp->session_key_len); On a binding SESSION_SETUP, auth_key points at the 16-byte channel_key, so a client that supplies an NTLM EncryptedRandomSessionKey of up to 40 bytes (with NTLMSSP_NEGOTIATE_KEY_EXCH), or a Kerberos ticket whose session key is longer than 16 bytes (a normal AES256 key is 32), writes past the 16-byte stack buffer -- up to a 24-byte kernel stack overflow. KASAN reports it as a stack-out-of-bounds write in arc4_crypt() called from ksmbd_decode_ntlmssp_auth_blob(). The destinations must be able to hold the full session key the length checks already permit. Size the per-channel key buffer and the two on-stack channel_key buffers with CIFS_KEY_SIZE, matching sess->sess_key. Fixes: 4b706360ffb7 ("ksmbd: fix multichannel binding and enforce channel limit") Signed-off-by: Gil Portnoy <dddhkts1@gmail.com> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-07-16ksmbd: fix memory leak of xattr_stream_name in smb2_rename()Gil Portnoy
On an SMB2 SET_INFO(FileRenameInformation) whose target names an alternate data stream, smb2_rename() obtains a formatted stream-name string from ksmbd_vfs_xattr_stream_name(), which allocates it with kasprintf() and returns it through an out-param: rc = ksmbd_vfs_xattr_stream_name(stream_name, &xattr_stream_name, ...); if (rc) goto out; rc = ksmbd_vfs_setxattr(..., xattr_stream_name, ...); if (rc < 0) { ... goto out; } goto out; xattr_stream_name is declared inside the alternate-data-stream block, but the out: label is outside that block and frees only new_name, so it cannot release xattr_stream_name. ksmbd_vfs_setxattr() takes a const char * and only reads the name, so it does not take ownership either. Both the setxattr-failure and the success path therefore leak the kasprintf()'d string. An authenticated client with a writable share can leak kernel memory on every stream rename, exhausting kernel memory over time. Free xattr_stream_name after its use, before the block's goto out. The two earlier goto out paths never assign the variable, so there is no double-free. Signed-off-by: Gil Portnoy <dddhkts1@gmail.com> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-07-16ksmbd: zero the smb2_read alignment tail to avoid an infoleakGil Portnoy
Commit 6b9a2e09d4cc ("ksmbd: avoid zeroing the read buffer in smb2_read()") switched the SMB2 READ payload buffer from kvzalloc() to kvmalloc(), on the premise that only the nbytes actually read are ever transmitted, so the ALIGN(length, 8) tail need not be initialized. That premise does not hold for a compound response. ksmbd_vfs_read() fills only nbytes, leaving [nbytes, ALIGN(length, 8)) uninitialized. The aux payload is pinned as the last response iov with iov_len == nbytes, but when the READ is a member of a compound, init_chained_smb2_rsp() 8-byte-aligns the previous member by extending that same iov: new_len = ALIGN(len, 8); work->iov[work->iov_idx].iov_len += (new_len - len); inc_rfc1001_len(work->response_buf, new_len - len); so up to 7 uninitialized bytes of the kvmalloc()'d slab tail are sent to the client. When the read length is small the buffer is served from a general kmalloc slab, so those bytes can be stale kernel-heap contents, including pointer values -- an information leak usable to defeat KASLR. An authenticated client triggers it with a compound request containing a READ whose returned nbytes is not 8-aligned (for example [READ, CLOSE] with a 1-byte read). Zero only the alignment tail after the read, preserving the bulk no-zeroing optimization of 6b9a2e09d4cc. Fixes: 6b9a2e09d4cc ("ksmbd: avoid zeroing the read buffer in smb2_read()") Cc: stable@vger.kernel.org Signed-off-by: Gil Portnoy <dddhkts1@gmail.com> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-07-16ksmbd: pin conn during async oplock break notificationQihang
smb2_oplock_break_noti() and smb2_lease_break_noti() store a ksmbd_conn pointer in an async ksmbd_work and then queue that work on ksmbd-io. The work only increments conn->r_count, which prevents teardown from passing the pending-request wait after the increment, but it does not pin the struct ksmbd_conn object. If connection teardown races with an oplock break notification, the last conn reference can be dropped before the queued worker finishes. The worker then uses the freed conn in ksmbd_conn_write() and ksmbd_conn_r_count_dec(). Take a real conn reference when publishing the conn pointer to the async work item, and drop it after the notification work has decremented r_count. Apply the same lifetime rule to lease break notification, which uses the same work->conn pattern. Fixes: 3aa660c05924 ("ksmbd: prevent connection release during oplock break notification") Signed-off-by: Qihang <q.h.hack.winter@gmail.com> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-07-16ksmbd: fix integer overflow in set_file_allocation_info()Ibrahim Hashimov
set_file_allocation_info() converts the client-supplied FILE_ALLOCATION_INFORMATION::AllocationSize into a 512-byte block count with: alloc_blks = (le64_to_cpu(file_alloc_info->AllocationSize) + 511) >> 9; AllocationSize is a fully client-controlled __le64 field; the only validation performed by the caller (smb2_set_info_file(), case FILE_ALLOCATION_INFORMATION) is that the fixed buffer is at least sizeof(struct smb2_file_alloc_info) == 8 bytes. The value itself is never range-checked before this arithmetic. When AllocationSize is close to U64_MAX (e.g. 0xffffffffffffffff), "AllocationSize + 511" wraps around mod 2^64 to a small number (0xffffffffffffffff + 511 = 510), so alloc_blks becomes 0. Since any existing regular file has stat.blocks > 0, the function then takes the "shrink" branch and calls: ksmbd_vfs_truncate(work, fp, alloc_blks * 512); /* == 0 */ silently truncating the file to size 0, even though the client asked to grow the allocation to (what looks like) the maximum possible size. The trailing "if (size < alloc_blks * 512) i_size_write(inode, size);" restore is guarded by a comparison that is never true once alloc_blks == 0, so the truncation is not undone. This lets an authenticated SMB client that already holds an open handle with FILE_WRITE_DATA on a file silently truncate that same file to size 0 via a single crafted SET_INFO(FILE_ALLOCATION_INFORMATION) request advertising a near-U64_MAX AllocationSize, even though the request asks to grow the file's allocation rather than shrink it. This is a functional/data-loss bug, not a privilege-boundary violation: the same client could already truncate the file via FILE_END_OF_FILE_INFORMATION or a plain write. Fix it by validating AllocationSize against MAX_LFS_FILESIZE, the same upper bound the VFS itself uses to reject unrepresentable file sizes, before doing the "+511" rounding, and rejecting oversized values with -EINVAL. Bounding AllocationSize to MAX_LFS_FILESIZE - 511 guarantees the "+511" addition cannot wrap, and that the subsequent "alloc_blks * 512" values passed to vfs_fallocate() and ksmbd_vfs_truncate() stay within a representable loff_t as well. No legitimate SMB client asks for an allocation size anywhere near 2^64 bytes, so this only rejects a value that was previously silently misinterpreted as zero. Runtime-verified on a v6.19 KASAN test stand: sending SET_INFO (FILE_ALLOCATION_INFORMATION) with AllocationSize = 0xffffffffffffffff against ksmbd now returns -EINVAL and leaves the target file's size unchanged, where the unpatched kernel truncated it from 4096 to 0 bytes. Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org Signed-off-by: Ibrahim Hashimov <security@auditcode.ai> Assisted-by: AuditCode-AI:2026.07 Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-07-14smb/client: flush dirty data before punching a holeHuiwen He
Punching a hole after a large buffered write may leave the range reported as data. Reproduce it with: xfs_io -f \ -c "pwrite -b 3m -S 0x61 0 3m" \ -c "fpunch 1m 1m" \ -c "seek -h 0" \ -c "seek -d 1m" \ /mnt/test/repro Punching 1 MiB at offset 1 MiB should produce: 0 1 MiB 2 MiB 3 MiB | DATA | HOLE | DATA | EOF Instead, the entire file is reported as data. SEEK_HOLE(0) returns EOF, and SEEK_DATA(1M) returns 1M. This happens because a dirty folio spanning the punched range can be written back after the punch and refill the hole. Fix this by flushing and waiting for dirty data in the punched range before invalidating the page cache and issuing FSCTL_SET_ZERO_DATA. The xfstests generic/539 pass against Samba/ksmbd with this change. Signed-off-by: Huiwen He <hehuiwen@kylinos.cn> Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-07-14smb/client: Use EXPORT_SYMBOL_IF_KUNIT() to export symbols in SMB2Andy Shevchenko
Replace EXPORT_SYMBOL_FOR_MODULES() with EXPORT_SYMBOL_IF_KUNIT() to mark the symbols as visible only if CONFIG_KUNIT is enabled. Kunit test should import the namespace EXPORTED_FOR_KUNIT_TESTING to use these marked symbols. This is the standard way for all KUnit tests. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-07-14smb/client: Use EXPORT_SYMBOL_IF_KUNIT() to export symbolsAndy Shevchenko
Replace EXPORT_SYMBOL_FOR_MODULES() with EXPORT_SYMBOL_IF_KUNIT() to mark the symbols as visible only if CONFIG_KUNIT is enabled. Kunit test should import the namespace EXPORTED_FOR_KUNIT_TESTING to use these marked symbols. This is the standard way for all KUnit tests. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-07-14dax: fix misleading comment about share/index union in dax_folio_reset_order()John Groves
The comment in dax_folio_reset_order() claims that DAX maintains an invariant where folio->share != 0 only when folio->mapping == NULL, implying folio->share is zero whenever mapping is non-NULL. This is misleading because folio->share and folio->index are a union -- for non-shared folios with mapping != NULL, reading folio->share returns the file page offset (folio->index), which is typically non-zero. Reword the comment to accurately describe the union aliasing: the assignment clears whichever interpretation of the union word is active (index for non-shared folios, share for shared folios), which is correct because the folio is being released in either case. No functional change -- the code was already correct, only the justification was wrong. Fixes: 59eb73b98ae0b ("dax: Factor out dax_folio_reset_order() helper") Reviewed-by: Jonathan Cameron <jic23@kernel.org> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Signed-off-by: John Groves <john@groves.net> Link: https://patch.msgid.link/0100019ecc08b8cd-4ee80eeb-1341-4f67-8478-7298129440e9-000000@email.amazonses.com Signed-off-by: Alison Schofield <alison.schofield@intel.com>
2026-07-14hfs: don't re-dirty MDB buffers after a write failureViacheslav Dubeyko
hfs_mdb_commit() and hfs_mdb_close() keep the MDB and alternate-MDB buffer heads (mdb_bh, alt_mdb_bh) pinned for the lifetime of the mount and write into them in place. If a write against the backing device fails, the block layer clears BH_Uptodate on the buffer (end_buffer_write_sync(), fs/buffer.c) to mark its contents as no longer trustworthy. !buffer_uptodate(bh) WARNING: fs/buffer.c:1093 at mark_buffer_dirty+0x299/0x410 fs/buffer.c:1093, CPU#0: syz.1.1033/6784 Modules linked in: CPU: 0 UID: 0 PID: 6784 Comm: syz.1.1033 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:mark_buffer_dirty+0x299/0x410 fs/buffer.c:1093 Code: 4c 89 f7 e8 f9 0d d9 ff 49 8b 3e be 40 00 00 00 5b 41 5c 41 5e 41 5f 5d e9 d4 5e fb ff e8 af e7 69 ff eb 8c e8 a8 e7 69 ff 90 <0f> 0b 90 e9 a5 fd ff ff e8 9a e7 69 ff 90 0f 0b 90 e9 cf fd ff ff RSP: 0018:ffffc90005d379a8 EFLAGS: 00010293 RAX: ffffffff825c9ae8 RBX: ffff8880123aa700 RCX: ffff888034a30000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002 RBP: 1ffff1100a45f401 R08: ffff8880123aa707 R09: 1ffff110024754e0 R10: dffffc0000000000 R11: ffffed10024754e1 R12: dffffc0000000000 R13: ffff8880522fa668 R14: ffff888045ba945b R15: ffff888045ba9400 FS: 000055556b366500(0000) GS:ffff88808c54e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b31a63fff CR3: 0000000034b1d000 CR4: 0000000000352ef0 Call Trace: <TASK> hfs_mdb_commit+0x503/0x1160 fs/hfs/mdb.c:309 hfs_sync_fs+0x1d/0x30 fs/hfs/super.c:38 sync_filesystem+0x1cf/0x230 fs/sync.c:66 fs_bdev_sync+0x2c/0x50 fs/super.c:1433 blkdev_flushbuf block/ioctl.c:520 [inline] blkdev_common_ioctl+0x12e1/0x3250 block/ioctl.c:658 blkdev_ioctl+0x528/0x740 block/ioctl.c:791 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1d9239de59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fffd0ece148 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f1d92625fa0 RCX: 00007f1d9239de59 RDX: 0000000000000000 RSI: 0000000000001261 RDI: 0000000000000004 RBP: 00007f1d92433e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1d92625fac R14: 00007f1d92625fa0 R15: 00007f1d92625fa0 </TASK> This was found by fuzzing an HFS image on a loop device backed by a memfd; under memory pressure the shmem write-back path returned -ENOSPC (mm/shmem.c, shmem_acct_blocks()), which surfaced as a plain write error on the block device. The call path: ioctl(BLKFLSBUF) -> blkdev_common_ioctl() -> sync_filesystem() -> hfs_sync_fs() -> hfs_mdb_commit(). Check buffer_uptodate() on mdb_bh/alt_mdb_bh before dirtying them. If either has gone stale, mark the volume read-only and skip the write instead of asserting on it. Also, hfs_mdb_commit() returns -EIO error code in such situation. As a result, hfs_sync_fs() can report the failure instead of always returning 0. The sync()/fsync()/BLKFLSBUF now observe -EIO instead of silently succeeding while the volume goes read-only underneath them. Reported-by: syzbot+c149ad75e9633be0c1ad@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=c149ad75e9633be0c1ad cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> cc: Yangtao Li <frank.li@vivo.com> cc: linux-fsdevel@vger.kernel.org Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com> Link: https://lore.kernel.org/r/20260709225001.473320-2-slava@dubeyko.com Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
2026-07-14hfsplus: fix error code when writing beyond volume capacityViacheslav Dubeyko
The xfstests' test-case generic/564 fails for the case of HFS+ file system. Test-case expects that file system driver reports -EFBIG error code in the case if there is the effort to write beyond 8TiB. However, HFS+ file system driver returns -ENOSPC instead. The root cause is that hfsplus_fill_super() sets s_maxbytes as MAX_LFS_FILESIZE. VFS therefore considers the write position valid and calls into the filesystem. Because HFS+ does not support holes, cont_write_begin() zero-fills the entire intermediate range from the current end-of-file to the target offset. On a small test volume this exhausts free space long before any block-number overflow is detected, producing -ENOSPC instead of -EFBIG. This patch fixes the issue by adding a bounds check at the top of hfsplus_write_begin(). If the requested write position is at or beyond the actual capacity of the volume in bytes, return -EFBIG immediately before cont_write_begin() is entered and before any zero-fill I/O is attempted. sudo ./check generic/564 FSTYP -- hfsplus PLATFORM -- Linux/x86_64 hfsplus-testing-0001 7.2.0-rc1-dirty #50 SMP PREEMPT_DYNAMIC Fri Jul 3 16:22:27 PDT 2026 MKFS_OPTIONS -- /dev/loop51 MOUNT_OPTIONS -- /dev/loop51 /mnt/scratch generic/564 13s ... 43s Ran: generic/564 Passed all 1 tests cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> cc: Yangtao Li <frank.li@vivo.com> cc: linux-fsdevel@vger.kernel.org Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com> Link: https://lore.kernel.org/r/20260706221738.140271-2-slava@dubeyko.com Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
2026-07-14hfs: fix error code when writing beyond volume capacityViacheslav Dubeyko
Likewise HFS+, HFS has the same issue of returning the -ENOSPC error code instead of -EFBIG in the case if there is the effort to write beyond 8TiB. The root cause is that hfs_fill_super() sets s_maxbytes as MAX_LFS_FILESIZE. VFS therefore considers the write position valid and calls into the filesystem. Because HFS does not support holes, cont_write_begin() zero-fills the entire intermediate range from the current end-of-file to the target offset. On a small test volume this exhausts free space long before any block-number overflow is detected, producing -ENOSPC instead of -EFBIG. This patch fixes the issue by adding a bounds check at the top of hfs_write_begin(). If the requested write position is at or beyond the actual capacity of the volume in bytes, return -EFBIG immediately before cont_write_begin() is entered and before any zero-fill I/O is attempted. cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> cc: Yangtao Li <frank.li@vivo.com> cc: linux-fsdevel@vger.kernel.org Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com> Link: https://lore.kernel.org/r/20260706221804.140295-2-slava@dubeyko.com Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>