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2026-06-219p: Add missing read barrier in virtio zero-copy pathGui-Dong Han
Commit 2b6e72ed747f ("9P: Add memory barriers to protect request fields over cb/rpc threads handoff") added a read barrier after p9_client_rpc() waits for req->status, pairing with the write barrier in p9_client_cb(). The virtio zero-copy wait path was missed. Add the same read barrier after the zero-copy wait before reading the completed request. Fixes: 2b6e72ed747f ("9P: Add memory barriers to protect request fields over cb/rpc threads handoff") Signed-off-by: Gui-Dong Han <hanguidong02@gmail.com> Message-ID: <20260529075441.233369-1-hanguidong02@gmail.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2026-06-21net/9p: Replace strlen() strcpy() pair with strscpy()David Laight
Use the result of strscpy() for the overflow check. Signed-off-by: David Laight <david.laight.linux@gmail.com> Message-ID: <20260606202744.5113-3-david.laight.linux@gmail.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2026-06-21net/9p: fix race condition on rdma->state in trans_rdma.cYizhou Zhao
The rdma->state field is modified without holding req_lock in both recv_done() and p9_cm_event_handler(), while rdma_request() accesses the same field under the req_lock spinlock. This inconsistent locking creates a race condition: - recv_done() running in softirq completion context sets rdma->state = P9_RDMA_FLUSHING without acquiring req_lock - p9_cm_event_handler() modifies rdma->state at multiple points (ADDR_RESOLVED, ROUTE_RESOLVED, ESTABLISHED, CLOSED) without req_lock - rdma_request() uses spin_lock_irqsave(&rdma->req_lock, flags) to protect the read-modify-write of rdma->state The race can cause lost state transitions: recv_done() or the CM event handler could set state to FLUSHING/CLOSED while rdma_request() is concurrently checking or modifying state under the lock, leading to the FLUSHING transition being silently overwritten by CLOSING. This corrupts the connection state machine and can cause use-after-free on RDMA request objects during teardown. Fix by adding req_lock protection to all rdma->state modifications in recv_done() and p9_cm_event_handler(), matching the pattern already used in rdma_request(). Use spin_lock_irqsave/spin_unlock_irqrestore in the CM event handler since it can race with recv_done() which runs in softirq context. Tested with a kernel module that races two threads (simulating rdma_request and recv_done/CM handler) on rdma->state with proper locking: 5.5M+ FLUSHING writes over 27M iterations with 0 lost transitions. Fixes: 473c7dd1d7b5 ("9p/rdma: remove useless check in cm_event_handler") Reported-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn> Reported-by: Yuxiang Yang <yangyx22@mails.tsinghua.edu.cn> Reported-by: Ao Wang <wangao@seu.edu.cn> Reported-by: Xuewei Feng <fengxw06@126.com> Reported-by: Qi Li <qli01@tsinghua.edu.cn> Reported-by: Ke Xu <xuke@tsinghua.edu.cn> Assisted-by: GLM:GLM-5.1 Signed-off-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn> Message-ID: <20260529073933.77315-1-zhaoyz24@mails.tsinghua.edu.cn> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2026-06-219p: avoid putting oldfid in p9_client_walk() error pathYizhou Zhao
When p9_client_walk() is called with clone set to false, fid aliases oldfid. If the walk subsequently fails after the request has been sent, the error path jumps to clunk_fid, which currently calls p9_fid_put(fid) unconditionally. This drops a reference to oldfid even though ownership of oldfid remains with the caller. If this is the last reference, oldfid can be clunked and destroyed while the caller still expects it to be valid. A later use or put of oldfid can then trigger a use-after-free or refcount underflow. Fix this by only putting fid in the clunk_fid error path when it does not alias oldfid, matching the existing guard in the error path below. This can be triggered when a multi-component walk is split into multiple p9_client_walk() calls and a later non-cloning walk fails. A reproducer and refcount warning logs are available on request. Fixes: b48dbb998d70 ("9p fid refcount: add p9_fid_get/put wrappers") Cc: stable@vger.kernel.org Reported-by: Yuxiang Yang <yangyx22@mails.tsinghua.edu.cn> Reported-by: Ao Wang <wangao@seu.edu.cn> Reported-by: Xuewei Feng <fengxw06@126.com> Reported-by: Qi Li <qli01@tsinghua.edu.cn> Reported-by: Ke Xu <xuke@tsinghua.edu.cn> Assisted-by: GLM 5.1 Signed-off-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn> Message-ID: <20260528053918.53550-1-zhaoyz24@mails.tsinghua.edu.cn> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2026-05-29net/9p: fix infinite loop in p9_client_rpc on fatal signalVasiliy Kovalev
When p9_client_rpc() is called with type P9_TFLUSH and the transport has no peer (e.g. fd transport backed by pipes with no 9p server), a fatal signal causes an infinite loop: again: err = io_wait_event_killable(req->wq, ...) /* SIGKILL wakes the task, returns -ERESTARTSYS */ if (err == -ERESTARTSYS && c->status == Connected && type == P9_TFLUSH) { sigpending = 1; clear_thread_flag(TIF_SIGPENDING); goto again; } clear_thread_flag() clears TIF_SIGPENDING before jumping back to io_wait_event_killable(). signal_pending_state() checks TIF_SIGPENDING, finds it zero, and the task goes to sleep again. The task can only wake on the next signal delivery that calls signal_wake_up() and sets TIF_SIGPENDING again. When that happens the loop repeats, clears TIF_SIGPENDING, and sleeps again indefinitely. This is triggered in practice by coredump_wait(): when a thread in a multi-threaded process causes a coredump (e.g. via SIGSYS from Syscall User Dispatch), coredump_wait() sends SIGKILL to all other threads and waits for them to call mm_release(). If one of those threads is blocked in p9_client_rpc() over an fd transport with no peer, it enters the P9_TFLUSH loop and never calls mm_release(), so coredump_wait() stalls forever: INFO: task syz.0.18:676 blocked for more than 143 seconds. Not tainted 6.12.77+ #1 task:syz.0.18 state:D stack:27600 pid:676 tgid:673 ppid:630 flags:0x00000004 Call Trace: <TASK> context_switch kernel/sched/core.c:5344 [inline] __schedule+0xcb4/0x5d50 kernel/sched/core.c:6724 __schedule_loop kernel/sched/core.c:6801 [inline] schedule+0xe5/0x350 kernel/sched/core.c:6816 schedule_timeout+0x253/0x290 kernel/time/timer.c:2593 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common+0x409/0x600 kernel/sched/completion.c:116 wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion_state+0x1d/0x40 kernel/sched/completion.c:264 coredump_wait fs/coredump.c:448 [inline] do_coredump+0x854/0x4350 fs/coredump.c:629 get_signal+0x1425/0x2730 kernel/signal.c:2903 arch_do_signal_or_restart+0x81/0x880 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xf9/0x160 kernel/entry/common.c:218 do_syscall_64+0x102/0x220 arch/x86/entry/common.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f </TASK> Fix: check fatal_signal_pending() before clearing TIF_SIGPENDING in the P9_TFLUSH retry loop. At that point TIF_SIGPENDING is still set, so fatal_signal_pending() works correctly. If a fatal signal is pending, jump to recalc_sigpending to restore TIF_SIGPENDING and return -ERESTARTSYS to the caller. The same defect is present in stable kernels back to 5.4. On those kernels the infinite loop is broken earlier by a second SIGKILL from the parent process (e.g. kill_and_wait() retrying after a timeout), resulting in a zombie process and a shutdown delay rather than a permanent D-state hang, but the underlying flaw is the same. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Fixes: 91b8534fa8f5 ("9p: make rpc code common and rework flush code") Closes: https://syzkaller.appspot.com/bug?extid=3ce7863f8fc836a427e7 Cc: stable@vger.kernel.org Signed-off-by: Vasiliy Kovalev <kovalev@altlinux.org> Message-ID: <20260415155237.182891-1-kovalev@altlinux.org> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2026-05-199p: use kvzalloc for readdir bufferPierre Barre
The readdir buffer is sized to msize, so kzalloc() can fail under fragmentation with a page allocation failure in v9fs_alloc_rdir_buf() / v9fs_dir_readdir_dotl(). The buffer is only a response sink and is never pack_sg_list()'d, so kvzalloc() is safe for all transports, unlike the fcall buffers fixed in e21d451a82f3 ("9p: Use kvmalloc for message buffers on supported transports"). Signed-off-by: Pierre Barre <pierre@barre.sh> Message-ID: <20260512132032.369281-1-pierre@barre.sh> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2026-05-19net/9p/usbg: Constify struct configfs_item_operationsChristophe JAILLET
'struct configfs_item_operations' is not modified in this driver. Constifying this structure moves some data to a read-only section, so increases overall security, especially when the structure holds some function pointers. On a x86_64, with allmodconfig: Before: ====== text data bss dec hex filename 25167 9336 256 34759 87c7 net/9p/trans_usbg.o After: ===== text data bss dec hex filename 25231 9272 256 34759 87c7 net/9p/trans_usbg.o Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Message-ID: <2478bdabd7d169a686879c049f11dc307b5debbd.1778922467.git.christophe.jaillet@wanadoo.fr> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2026-04-169p/trans_xen: replace simple_strto* with kstrtouintYufan Chen
In xen_9pfs_front_init(), parse the backend version list as comma-separated tokens with kstrtouint(), keep strict token validation, and explicitly require protocol version 1 to be present. This replaces the deprecated simple_strtoul(), improves error reporting consistency, and avoids partially parsed values in control paths. Signed-off-by: Yufan Chen <ericterminal@gmail.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Message-ID: <20260324153023.86853-3-ericterminal@gmail.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2026-04-169p/trans_xen: make cleanup idempotent after dataring alloc errorsYufan Chen
xen_9pfs_front_alloc_dataring() tears down resources on failure but leaves ring fields stale. If xen_9pfs_front_init() later jumps to the common error path, xen_9pfs_front_free() may touch the same resources again, causing duplicate/invalid gnttab_end_foreign_access() calls and potentially dereferencing a freed intf pointer. Initialize dataring sentinels before allocation, gate teardown on those sentinels, and clear ref/intf/data/irq immediately after each release. This keeps cleanup idempotent for partially initialized rings and prevents repeated teardown during init failure handling. Signed-off-by: Yufan Chen <ericterminal@gmail.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Message-ID: <20260324153023.86853-2-ericterminal@gmail.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2026-02-21Convert 'alloc_obj' family to use the new default GFP_KERNEL argumentLinus Torvalds
This was done entirely with mindless brute force, using git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' | xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/' to convert the new alloc_obj() users that had a simple GFP_KERNEL argument to just drop that argument. Note that due to the extreme simplicity of the scripting, any slightly more complex cases spread over multiple lines would not be triggered: they definitely exist, but this covers the vast bulk of the cases, and the resulting diff is also then easier to check automatically. For the same reason the 'flex' versions will be done as a separate conversion. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org>
2026-01-299p/xen: protect xen_9pfs_front_free against concurrent callsStefano Stabellini
The xenwatch thread can race with other back-end change notifications and call xen_9pfs_front_free() twice, hitting the observed general protection fault due to a double-free. Guard the teardown path so only one caller can release the front-end state at a time, preventing the crash. This is a fix for the following double-free: [ 27.052347] Oops: general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b6b: 0000 [#1] SMP DEBUG_PAGEALLOC NOPTI [ 27.052357] CPU: 0 UID: 0 PID: 32 Comm: xenwatch Not tainted 6.18.0-02087-g51ab33fc0a8b-dirty #60 PREEMPT(none) [ 27.052363] RIP: e030:xen_9pfs_front_free+0x1d/0x150 [ 27.052368] Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 41 55 41 54 55 48 89 fd 48 c7 c7 48 d0 92 85 53 e8 cb cb 05 00 48 8b 45 08 48 8b 55 00 <48> 3b 28 0f 85 f9 28 35 fe 48 3b 6a 08 0f 85 ef 28 35 fe 48 89 42 [ 27.052377] RSP: e02b:ffffc9004016fdd0 EFLAGS: 00010246 [ 27.052381] RAX: 6b6b6b6b6b6b6b6b RBX: ffff88800d66e400 RCX: 0000000000000000 [ 27.052385] RDX: 6b6b6b6b6b6b6b6b RSI: 0000000000000000 RDI: 0000000000000000 [ 27.052389] RBP: ffff88800a887040 R08: 0000000000000000 R09: 0000000000000000 [ 27.052393] R10: 0000000000000000 R11: 0000000000000000 R12: ffff888009e46b68 [ 27.052397] R13: 0000000000000200 R14: 0000000000000000 R15: ffff88800a887040 [ 27.052404] FS: 0000000000000000(0000) GS:ffff88808ca57000(0000) knlGS:0000000000000000 [ 27.052408] CS: e030 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 27.052412] CR2: 00007f9714004360 CR3: 0000000004834000 CR4: 0000000000050660 [ 27.052418] Call Trace: [ 27.052420] <TASK> [ 27.052422] xen_9pfs_front_changed+0x5d5/0x720 [ 27.052426] ? xenbus_otherend_changed+0x72/0x140 [ 27.052430] ? __pfx_xenwatch_thread+0x10/0x10 [ 27.052434] xenwatch_thread+0x94/0x1c0 [ 27.052438] ? __pfx_autoremove_wake_function+0x10/0x10 [ 27.052442] kthread+0xf8/0x240 [ 27.052445] ? __pfx_kthread+0x10/0x10 [ 27.052449] ? __pfx_kthread+0x10/0x10 [ 27.052452] ret_from_fork+0x16b/0x1a0 [ 27.052456] ? __pfx_kthread+0x10/0x10 [ 27.052459] ret_from_fork_asm+0x1a/0x30 [ 27.052463] </TASK> [ 27.052465] Modules linked in: [ 27.052471] ---[ end trace 0000000000000000 ]--- Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com> Message-ID: <20260129230348.2390470-1-stefano.stabellini@amd.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2026-01-299p: Track 9P RPC waiting time as IORemi Pommarel
Use io_wait_event_killable() to ensure that time spent waiting for 9P RPC transactions is accounted as IO wait time. Signed-off-by: Remi Pommarel <repk@triplefau.lt> Message-ID: <b8601271263011203fa34eada2e8ac21d9f679e5.1769179462.git.repk@triplefau.lt> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2025-12-07Merge tag '9p-for-6.19-rc1' of https://github.com/martinetd/linuxLinus Torvalds
Pull 9p updates from Dominique Martinet: - fix a bug with O_APPEND in cached mode causing data to be written multiple times on server - use kvmalloc for trans_fd to avoid problems with large msize and fragmented memory This should hopefully be used in more transports when time allows - convert to new mount API - minor cleanups * tag '9p-for-6.19-rc1' of https://github.com/martinetd/linux: 9p: fix new mount API cache option handling 9p: fix cache/debug options printing in v9fs_show_options 9p: convert to the new mount API 9p: create a v9fs_context structure to hold parsed options net/9p: move structures and macros to header files fs/fs_parse: add back fsparam_u32hex fs/9p: delete unnnecessary condition fs/9p: Don't open remote file with APPEND mode when writeback cache is used net/9p: cleanup: change p9_trans_module->def to bool 9p: Use kvmalloc for message buffers on supported transports
2025-11-04net: Convert proto_ops connect() callbacks to use sockaddr_unsizedKees Cook
Update all struct proto_ops connect() callback function prototypes from "struct sockaddr *" to "struct sockaddr_unsized *" to avoid lying to the compiler about object sizes. Calls into struct proto handlers gain casts that will be removed in the struct proto conversion patch. No binary changes expected. Signed-off-by: Kees Cook <kees@kernel.org> Link: https://patch.msgid.link/20251104002617.2752303-3-kees@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-04net: Convert proto_ops bind() callbacks to use sockaddr_unsizedKees Cook
Update all struct proto_ops bind() callback function prototypes from "struct sockaddr *" to "struct sockaddr_unsized *" to avoid lying to the compiler about object sizes. Calls into struct proto handlers gain casts that will be removed in the struct proto conversion patch. No binary changes expected. Signed-off-by: Kees Cook <kees@kernel.org> Link: https://patch.msgid.link/20251104002617.2752303-2-kees@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-039p: convert to the new mount APIEric Sandeen
Convert 9p to the new mount API. This patch consolidates all parsing into fs/9p/v9fs.c, which stores all results into a filesystem context which can be passed to the various transports as needed. Some of the parsing helper functions such as get_cache_mode() have been eliminated in favor of using the new mount API's enum param type, for simplicity. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Message-ID: <20251010214222.1347785-5-sandeen@redhat.com> [ Dominique: handled source explicitly as per follow-up discussion ] Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2025-11-03net/9p: move structures and macros to header filesEric Sandeen
With the new mount API all option parsing will need to happen in fs/v9fs.c, so move some existing data structures and macros to header files to facilitate this. Rename some to reflect the transport they are used for (rdma, fd, etc), for clarity. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Message-ID: <20251010214222.1347785-3-sandeen@redhat.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2025-11-03net/9p: cleanup: change p9_trans_module->def to boolDominique Martinet
'->def' is only ever used as a true/false flag Reported-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Message-ID: <20251103-v9fs_trans_def_bool-v1-1-f33dc7ed9e81@codewreck.org> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2025-11-039p: Use kvmalloc for message buffers on supported transportsPierre Barre
While developing a 9P server (https://github.com/Barre/ZeroFS) and testing it under high-load, I was running into allocation failures. The failures occur even with plenty of free memory available because kmalloc requires contiguous physical memory. This results in errors like: ls: page allocation failure: order:7, mode:0x40c40(GFP_NOFS|__GFP_COMP) This patch introduces a transport capability flag (supports_vmalloc) that indicates whether a transport can work with vmalloc'd buffers (non-physically contiguous memory). Transports requiring DMA should leave this flag as false. The fd-based transports (tcp, unix, fd) set this flag to true, and p9_fcall_init will use kvmalloc instead of kmalloc for these transports. This allows the allocator to fall back to vmalloc when contiguous physical memory is not available. Additionally, if kmem_cache_alloc fails, the code falls back to kvmalloc for transports that support it. Signed-off-by: Pierre Barre <pierre@barre.sh> Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com> Message-ID: <d2017c29-11fb-44a5-bd0f-4204329bbefb@app.fastmail.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2025-09-199p/trans_fd: p9_fd_request: kick rx thread if EPOLLINOleg Nesterov
p9_read_work() doesn't set Rworksched and doesn't do schedule_work(m->rq) if list_empty(&m->req_list). However, if the pipe is full, we need to read more data and this used to work prior to commit aaec5a95d59615 ("pipe_read: don't wake up the writer if the pipe is still full"). p9_read_work() does p9_fd_read() -> ... -> anon_pipe_read() which (before the commit above) triggered the unnecessary wakeup. This wakeup calls p9_pollwake() which kicks p9_poll_workfn() -> p9_poll_mux(), p9_poll_mux() will notice EPOLLIN and schedule_work(&m->rq). This no longer happens after the optimization above, change p9_fd_request() to use p9_poll_mux() instead of only checking for EPOLLOUT. Reported-by: syzbot+d1b5dace43896bc386c3@syzkaller.appspotmail.com Tested-by: syzbot+d1b5dace43896bc386c3@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/68a2de8f.050a0220.e29e5.0097.GAE@google.com/ Link: https://lore.kernel.org/all/67dedd2f.050a0220.31a16b.003f.GAE@google.com/ Co-developed-by: K Prateek Nayak <kprateek.nayak@amd.com> Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Tested-by: K Prateek Nayak <kprateek.nayak@amd.com> Message-ID: <20250819161013.GB11345@redhat.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2025-08-23net/9p: fix double req put in p9_fd_cancelledNalivayko Sergey
Syzkaller reports a KASAN issue as below: general protection fault, probably for non-canonical address 0xfbd59c0000000021: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: maybe wild-memory-access in range [0xdead000000000108-0xdead00000000010f] CPU: 0 PID: 5083 Comm: syz-executor.2 Not tainted 6.1.134-syzkaller-00037-g855bd1d7d838 #0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:__list_del include/linux/list.h:114 [inline] RIP: 0010:__list_del_entry include/linux/list.h:137 [inline] RIP: 0010:list_del include/linux/list.h:148 [inline] RIP: 0010:p9_fd_cancelled+0xe9/0x200 net/9p/trans_fd.c:734 Call Trace: <TASK> p9_client_flush+0x351/0x440 net/9p/client.c:614 p9_client_rpc+0xb6b/0xc70 net/9p/client.c:734 p9_client_version net/9p/client.c:920 [inline] p9_client_create+0xb51/0x1240 net/9p/client.c:1027 v9fs_session_init+0x1f0/0x18f0 fs/9p/v9fs.c:408 v9fs_mount+0xba/0xcb0 fs/9p/vfs_super.c:126 legacy_get_tree+0x108/0x220 fs/fs_context.c:632 vfs_get_tree+0x8e/0x300 fs/super.c:1573 do_new_mount fs/namespace.c:3056 [inline] path_mount+0x6a6/0x1e90 fs/namespace.c:3386 do_mount fs/namespace.c:3399 [inline] __do_sys_mount fs/namespace.c:3607 [inline] __se_sys_mount fs/namespace.c:3584 [inline] __x64_sys_mount+0x283/0x300 fs/namespace.c:3584 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 This happens because of a race condition between: - The 9p client sending an invalid flush request and later cleaning it up; - The 9p client in p9_read_work() canceled all pending requests. Thread 1 Thread 2 ... p9_client_create() ... p9_fd_create() ... p9_conn_create() ... // start Thread 2 INIT_WORK(&m->rq, p9_read_work); p9_read_work() ... p9_client_rpc() ... ... p9_conn_cancel() ... spin_lock(&m->req_lock); ... p9_fd_cancelled() ... ... spin_unlock(&m->req_lock); // status rewrite p9_client_cb(m->client, req, REQ_STATUS_ERROR) // first remove list_del(&req->req_list); ... spin_lock(&m->req_lock) ... // second remove list_del(&req->req_list); spin_unlock(&m->req_lock) ... Commit 74d6a5d56629 ("9p/trans_fd: Fix concurrency del of req_list in p9_fd_cancelled/p9_read_work") fixes a concurrency issue in the 9p filesystem client where the req_list could be deleted simultaneously by both p9_read_work and p9_fd_cancelled functions, but for the case where req->status equals REQ_STATUS_RCVD. Update the check for req->status in p9_fd_cancelled to skip processing not just received requests, but anything that is not SENT, as whatever changed the state from SENT also removed the request from its list. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Fixes: afd8d6541155 ("9P: Add cancelled() to the transport functions.") Cc: stable@vger.kernel.org Signed-off-by: Nalivayko Sergey <Sergey.Nalivayko@kaspersky.com> Message-ID: <20250715154815.3501030-1-Sergey.Nalivayko@kaspersky.com> [updated the check from status == RECV || status == ERROR to status != SENT] Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2025-08-23net/9p: Fix buffer overflow in USB transport layerDominique Martinet
A buffer overflow vulnerability exists in the USB 9pfs transport layer where inconsistent size validation between packet header parsing and actual data copying allows a malicious USB host to overflow heap buffers. The issue occurs because: - usb9pfs_rx_header() validates only the declared size in packet header - usb9pfs_rx_complete() uses req->actual (actual received bytes) for memcpy This allows an attacker to craft packets with small declared size (bypassing validation) but large actual payload (triggering overflow in memcpy). Add validation in usb9pfs_rx_complete() to ensure req->actual does not exceed the buffer capacity before copying data. Reported-by: Yuhao Jiang <danisjiang@gmail.com> Closes: https://lkml.kernel.org/r/20250616132539.63434-1-danisjiang@gmail.com Fixes: a3be076dc174 ("net/9p/usbg: Add new usb gadget function transport") Cc: stable@vger.kernel.org Message-ID: <20250622-9p-usb_overflow-v3-1-ab172691b946@codewreck.org> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2025-05-21netfs: Fix the request's work item to not require a refDavid Howells
When the netfs_io_request struct's work item is queued, it must be supplied with a ref to the work item struct to prevent it being deallocated whilst on the queue or whilst it is being processed. This is tricky to manage as we have to get a ref before we try and queue it and then we may find it's already queued and is thus already holding a ref - in which case we have to try and get rid of the ref again. The problem comes if we're in BH or IRQ context and need to drop the ref: if netfs_put_request() reduces the count to 0, we have to do the cleanup - but the cleanup may need to wait. Fix this by adding a new work item to the request, ->cleanup_work, and dispatching that when the refcount hits zero. That can then synchronously cancel any outstanding work on the main work item before doing the cleanup. Adding a new work item also deals with another problem upstream where it's sometimes changing the work func in the put function and requeuing it - which has occasionally in the past caused the cleanup to happen incorrectly. As a bonus, this allows us to get rid of the 'was_async' parameter from a bunch of functions. This indicated whether the put function might not be permitted to sleep. Fixes: 3d3c95046742 ("netfs: Provide readahead and readpage netfs helpers") Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/20250519090707.2848510-4-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Steve French <stfrench@microsoft.com> cc: linux-cifs@vger.kernel.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-239p: Use hashtable.h for hash_errmapSasha Levin
Convert hash_errmap in error.c to use the generic hashtable implementation from hashtable.h instead of the manual hlist_head array implementation. This simplifies the code and makes it more maintainable by using the standard hashtable API and removes the need for manual hash table management. Signed-off-by: Sasha Levin <sashal@kernel.org> Message-ID: <20250320145200.3124863-1-sashal@kernel.org> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2025-03-199p/trans_fd: mark concurrent read and writes to p9_conn->errIgnacio Encinas
Writes for the error value of a connection are spinlock-protected inside p9_conn_cancel, but lockless reads are present elsewhere to avoid performing unnecessary work after an error has been met. Mark the write and lockless reads to make KCSAN happy. Mark the write as exclusive following the recommendation in "Lock-Protected Writes with Lockless Reads" in tools/memory-model/Documentation/access-marking.txt while we are at it. Mark p9_fd_request and p9_conn_cancel m->err reads despite the fact that they do not race with concurrent writes for stylistic reasons. Reported-by: syzbot+d69a7cc8c683c2cb7506@syzkaller.appspotmail.com Reported-by: syzbot+483d6c9b9231ea7e1851@syzkaller.appspotmail.com Signed-off-by: Ignacio Encinas <ignacio@iencinas.com> Message-ID: <20250318-p9_conn_err_benign_data_race-v3-1-290bb18335cc@iencinas.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2025-03-199p/net: return error on bogus (longer than requested) repliesDominique Martinet
Up until now we've been considering longer than requested replies as acceptable, printing a message and just truncating the data, but it makes more sense to consider these an error. Make these fail with EIO instead. Suggested-by: Christian Schoenebeck <linux_oss@crudebyte.com> Message-ID: <20250317-p9_bogus_io_error-v1-1-9639f6d1561f@codewreck.org> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2025-03-199p/net: fix improper handling of bogus negative read/write repliesDominique Martinet
In p9_client_write() and p9_client_read_once(), if the server incorrectly replies with success but a negative write/read count then we would consider written (negative) <= rsize (positive) because both variables were signed. Make variables unsigned to avoid this problem. The reproducer linked below now fails with the following error instead of a null pointer deref: 9pnet: bogus RWRITE count (4294967295 > 3) Reported-by: Robert Morris <rtm@mit.edu> Closes: https://lore.kernel.org/16271.1734448631@26-5-164.dynamic.csail.mit.edu Message-ID: <20250319-9p_unsigned_rw-v3-1-71327f1503d0@codewreck.org> Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2025-01-20net/9p/fd: support ipv6 for trans=tcpJoshua Murphy
Allows specifying an IPv6 address when mounting a remote 9p file system. Signed-off-by: Joshua Murphy <joshuamurphy@posteo.net> Message-ID: <20250118192122.327-2-joshuamurphy@posteo.net> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2024-11-22net/9p/usbg: allow building as standalone moduleDominique Martinet
There is no reason only the usbg transport would not be its own module, so make it tristate. In particular, this fixes a couple of issues the current bool had: - trans_usbg was apparently not compiled at all when NET_9P=m - the workaround added in commit 2193ede180dd ("net/9p/usbg: fix CONFIG_USB_GADGET dependency") became redundant because a tristate item cannot be built-in when its dependency is a module, so we can depend on USB_GADGET "normally" again. Cc: Michael Grzeschik <m.grzeschik@pengutronix.de> Link: https://lkml.kernel.org/r/ZzhWRPDNwu225NWz@codewreck.org Message-ID: <20241122144754.1231919-1-asmadeus@codewreck.org> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2024-11-229p/xen: fix release of IRQAlex Zenla
Kernel logs indicate an IRQ was double-freed. Pass correct device ID during IRQ release. Fixes: 71ebd71921e45 ("xen/9pfs: connect to the backend") Signed-off-by: Alex Zenla <alex@edera.dev> Signed-off-by: Alexander Merritt <alexander@edera.dev> Signed-off-by: Ariadne Conill <ariadne@ariadne.space> Reviewed-by: Juergen Gross <jgross@suse.com> Message-ID: <20241121225100.5736-1-alexander@edera.dev> [Dominique: remove confusing variable reset to 0] Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2024-11-219p/xen: fix init sequenceAlex Zenla
Large amount of mount hangs observed during hotplugging of 9pfs devices. The 9pfs Xen driver attempts to initialize itself more than once, causing the frontend and backend to disagree: the backend listens on a channel that the frontend does not send on, resulting in stalled processing. Only allow initialization of 9p frontend once. Fixes: c15fe55d14b3b ("9p/xen: fix connection sequence") Signed-off-by: Alex Zenla <alex@edera.dev> Signed-off-by: Alexander Merritt <alexander@edera.dev> Signed-off-by: Ariadne Conill <ariadne@ariadne.space> Reviewed-by: Juergen Gross <jgross@suse.com> Message-ID: <20241119211633.38321-1-alexander@edera.dev> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2024-11-16net/9p/usbg: fix handling of the failed kzalloc() memory allocationMirsad Todorovac
On the linux-next, next-20241108 vanilla kernel, the coccinelle tool gave the following error report: ./net/9p/trans_usbg.c:912:5-11: ERROR: allocation function on line 911 returns NULL not ERR_PTR on failure kzalloc() failure is fixed to handle the NULL return case on the memory exhaustion. Fixes: a3be076dc174d ("net/9p/usbg: Add new usb gadget function transport") Cc: Michael Grzeschik <m.grzeschik@pengutronix.de> Cc: Eric Van Hensbergen <ericvh@kernel.org> Cc: Latchesar Ionkov <lucho@ionkov.net> Cc: Dominique Martinet <asmadeus@codewreck.org> Cc: Christian Schoenebeck <linux_oss@crudebyte.com> Cc: v9fs@lists.linux.dev Cc: linux-kernel@vger.kernel.org Signed-off-by: Mirsad Todorovac <mtodorovac69@gmail.com> Message-ID: <20241109211840.721226-2-mtodorovac69@gmail.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2024-10-219p: fix slab cache name creation for realLinus Torvalds
This was attempted by using the dev_name in the slab cache name, but as Omar Sandoval pointed out, that can be an arbitrary string, eg something like "/dev/root". Which in turn trips verify_dirent_name(), which fails if a filename contains a slash. So just make it use a sequence counter, and make it an atomic_t to avoid any possible races or locking issues. Reported-and-tested-by: Omar Sandoval <osandov@fb.com> Link: https://lore.kernel.org/all/ZxafcO8KWMlXaeWE@telecaster.dhcp.thefacebook.com/ Fixes: 79efebae4afc ("9p: Avoid creating multiple slab caches with the same name") Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Dominique Martinet <asmadeus@codewreck.org> Cc: Thorsten Leemhuis <regressions@leemhuis.info> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-10-19Merge tag '9p-for-6.12-rc4' of https://github.com/martinetd/linuxLinus Torvalds
Pull 9p fixes from Dominique Martinet: "Mashed-up update that I sat on too long: - fix for multiple slabs created with the same name - enable multipage folios - theorical fix to also look for opened fids by inode if none was found by dentry" [ Enabling multi-page folios should have been done during the merge window, but it's a one-liner, and the actual meat of the enablement is in netfs and already in use for other filesystems... - Linus ] * tag '9p-for-6.12-rc4' of https://github.com/martinetd/linux: 9p: Avoid creating multiple slab caches with the same name 9p: Enable multipage folios 9p: v9fs_fid_find: also lookup by inode if not found dentry
2024-10-09net/9p/usbg: Fix build errorJinjie Ruan
When CONFIG_NET_9P_USBG=y but CONFIG_USB_LIBCOMPOSITE=m and CONFIG_CONFIGFS_FS=m, the following build error occurs: riscv64-unknown-linux-gnu-ld: net/9p/trans_usbg.o: in function `usb9pfs_free_func': trans_usbg.c:(.text+0x124): undefined reference to `usb_free_all_descriptors' riscv64-unknown-linux-gnu-ld: net/9p/trans_usbg.o: in function `usb9pfs_rx_complete': trans_usbg.c:(.text+0x2d8): undefined reference to `usb_interface_id' riscv64-unknown-linux-gnu-ld: trans_usbg.c:(.text+0x2f6): undefined reference to `usb_string_id' riscv64-unknown-linux-gnu-ld: net/9p/trans_usbg.o: in function `usb9pfs_func_bind': trans_usbg.c:(.text+0x31c): undefined reference to `usb_ep_autoconfig' riscv64-unknown-linux-gnu-ld: trans_usbg.c:(.text+0x336): undefined reference to `usb_ep_autoconfig' riscv64-unknown-linux-gnu-ld: trans_usbg.c:(.text+0x378): undefined reference to `usb_assign_descriptors' riscv64-unknown-linux-gnu-ld: net/9p/trans_usbg.o: in function `f_usb9pfs_opts_buflen_store': trans_usbg.c:(.text+0x49e): undefined reference to `usb_put_function_instance' riscv64-unknown-linux-gnu-ld: net/9p/trans_usbg.o: in function `usb9pfs_alloc_instance': trans_usbg.c:(.text+0x5fe): undefined reference to `config_group_init_type_name' riscv64-unknown-linux-gnu-ld: net/9p/trans_usbg.o: in function `usb9pfs_alloc': trans_usbg.c:(.text+0x7aa): undefined reference to `config_ep_by_speed' riscv64-unknown-linux-gnu-ld: trans_usbg.c:(.text+0x7ea): undefined reference to `config_ep_by_speed' riscv64-unknown-linux-gnu-ld: net/9p/trans_usbg.o: in function `usb9pfs_set_alt': trans_usbg.c:(.text+0x828): undefined reference to `alloc_ep_req' riscv64-unknown-linux-gnu-ld: net/9p/trans_usbg.o: in function `usb9pfs_modexit': trans_usbg.c:(.exit.text+0x10): undefined reference to `usb_function_unregister' riscv64-unknown-linux-gnu-ld: net/9p/trans_usbg.o: in function `usb9pfs_modinit': trans_usbg.c:(.init.text+0x1e): undefined reference to `usb_function_register' Select the config for NET_9P_USBG to fix it. Fixes: a3be076dc174 ("net/9p/usbg: Add new usb gadget function transport") Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> Tested-by: Kexy Biscuit <kexybiscuit@aosc.io> Link: https://lore.kernel.org/r/20240930081520.2371424-1-ruanjinjie@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-239p: Avoid creating multiple slab caches with the same namePedro Falcato
In the spirit of [1], avoid creating multiple slab caches with the same name. Instead, add the dev_name into the mix. [1]: https://lore.kernel.org/all/20240807090746.2146479-1-pedro.falcato@gmail.com/ Signed-off-by: Pedro Falcato <pedro.falcato@gmail.com> Reported-by: syzbot+3c5d43e97993e1fa612b@syzkaller.appspotmail.com Message-ID: <20240807094725.2193423-1-pedro.falcato@gmail.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2024-09-11net/9p/usbg: fix CONFIG_USB_GADGET dependencyArnd Bergmann
When USB gadget support is in a loadable module, 9pfs cannot link to it as a built-in driver: x86_64-linux-ld: vmlinux.o: in function `usb9pfs_free_func': trans_usbg.c:(.text+0x1070012): undefined reference to `usb_free_all_descriptors' x86_64-linux-ld: vmlinux.o: in function `disable_ep': trans_usbg.c:(.text+0x1070528): undefined reference to `usb_ep_disable' x86_64-linux-ld: vmlinux.o: in function `usb9pfs_func_unbind': trans_usbg.c:(.text+0x10705df): undefined reference to `usb_ep_free_request' x86_64-linux-ld: trans_usbg.c:(.text+0x107061f): undefined reference to `usb_ep_free_request' x86_64-linux-ld: vmlinux.o: in function `usb9pfs_func_bind': trans_usbg.c:(.text+0x107069f): undefined reference to `usb_interface_id' x86_64-linux-ld: trans_usbg.c:(.text+0x10706b5): undefined reference to `usb_string_id' Change the Kconfig dependency to only allow this to be enabled when it can successfully link and work. Fixes: a3be076dc174 ("net/9p/usbg: Add new usb gadget function transport") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20240909111745.248952-1-arnd@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-03net/9p/usbg: Add new usb gadget function transportMichael Grzeschik
Add the new gadget function for 9pfs transport. This function is defining an simple 9pfs transport interface that consists of one in and one out endpoint. The endpoints transmit and receive the 9pfs protocol payload when mounting a 9p filesystem over usb. Tested-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com> Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de> Link: https://lore.kernel.org/r/20240116-ml-topic-u9p-v12-2-9a27de5160e0@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-29Merge tag '9p-for-6.10-rc2' of https://github.com/martinetd/linuxLinus Torvalds
Pull 9p fixes from Dominique Martinet: "Two fixes headed to stable trees: - a trace event was dumping uninitialized values - a missing lock that was thought to have exclusive access, and it turned out not to" * tag '9p-for-6.10-rc2' of https://github.com/martinetd/linux: 9p: add missing locking around taking dentry fid list net/9p: fix uninit-value in p9_client_rpc()
2024-05-23Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds
Pull virtio updates from Michael Tsirkin: "Several new features here: - virtio-net is finally supported in vduse - virtio (balloon and mem) interaction with suspend is improved - vhost-scsi now handles signals better/faster And fixes, cleanups all over the place" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (48 commits) virtio-pci: Check if is_avq is NULL virtio: delete vq in vp_find_vqs_msix() when request_irq() fails MAINTAINERS: add Eugenio Pérez as reviewer vhost-vdpa: Remove usage of the deprecated ida_simple_xx() API vp_vdpa: don't allocate unused msix vectors sound: virtio: drop owner assignment fuse: virtio: drop owner assignment scsi: virtio: drop owner assignment rpmsg: virtio: drop owner assignment nvdimm: virtio_pmem: drop owner assignment wifi: mac80211_hwsim: drop owner assignment vsock/virtio: drop owner assignment net: 9p: virtio: drop owner assignment net: virtio: drop owner assignment net: caif: virtio: drop owner assignment misc: nsm: drop owner assignment iommu: virtio: drop owner assignment drm/virtio: drop owner assignment gpio: virtio: drop owner assignment firmware: arm_scmi: virtio: drop owner assignment ...
2024-05-22net: 9p: virtio: drop owner assignmentKrzysztof Kozlowski
virtio core already sets the .owner, so driver does not need to. Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Message-Id: <20240331-module-owner-virtio-v2-18-98f04bfaf46a@linaro.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-05-21net/9p: fix uninit-value in p9_client_rpc()Nikita Zhandarovich
Syzbot with the help of KMSAN reported the following error: BUG: KMSAN: uninit-value in trace_9p_client_res include/trace/events/9p.h:146 [inline] BUG: KMSAN: uninit-value in p9_client_rpc+0x1314/0x1340 net/9p/client.c:754 trace_9p_client_res include/trace/events/9p.h:146 [inline] p9_client_rpc+0x1314/0x1340 net/9p/client.c:754 p9_client_create+0x1551/0x1ff0 net/9p/client.c:1031 v9fs_session_init+0x1b9/0x28e0 fs/9p/v9fs.c:410 v9fs_mount+0xe2/0x12b0 fs/9p/vfs_super.c:122 legacy_get_tree+0x114/0x290 fs/fs_context.c:662 vfs_get_tree+0xa7/0x570 fs/super.c:1797 do_new_mount+0x71f/0x15e0 fs/namespace.c:3352 path_mount+0x742/0x1f20 fs/namespace.c:3679 do_mount fs/namespace.c:3692 [inline] __do_sys_mount fs/namespace.c:3898 [inline] __se_sys_mount+0x725/0x810 fs/namespace.c:3875 __x64_sys_mount+0xe4/0x150 fs/namespace.c:3875 do_syscall_64+0xd5/0x1f0 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Uninit was created at: __alloc_pages+0x9d6/0xe70 mm/page_alloc.c:4598 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page mm/slub.c:2175 [inline] allocate_slab mm/slub.c:2338 [inline] new_slab+0x2de/0x1400 mm/slub.c:2391 ___slab_alloc+0x1184/0x33d0 mm/slub.c:3525 __slab_alloc mm/slub.c:3610 [inline] __slab_alloc_node mm/slub.c:3663 [inline] slab_alloc_node mm/slub.c:3835 [inline] kmem_cache_alloc+0x6d3/0xbe0 mm/slub.c:3852 p9_tag_alloc net/9p/client.c:278 [inline] p9_client_prepare_req+0x20a/0x1770 net/9p/client.c:641 p9_client_rpc+0x27e/0x1340 net/9p/client.c:688 p9_client_create+0x1551/0x1ff0 net/9p/client.c:1031 v9fs_session_init+0x1b9/0x28e0 fs/9p/v9fs.c:410 v9fs_mount+0xe2/0x12b0 fs/9p/vfs_super.c:122 legacy_get_tree+0x114/0x290 fs/fs_context.c:662 vfs_get_tree+0xa7/0x570 fs/super.c:1797 do_new_mount+0x71f/0x15e0 fs/namespace.c:3352 path_mount+0x742/0x1f20 fs/namespace.c:3679 do_mount fs/namespace.c:3692 [inline] __do_sys_mount fs/namespace.c:3898 [inline] __se_sys_mount+0x725/0x810 fs/namespace.c:3875 __x64_sys_mount+0xe4/0x150 fs/namespace.c:3875 do_syscall_64+0xd5/0x1f0 entry_SYSCALL_64_after_hwframe+0x6d/0x75 If p9_check_errors() fails early in p9_client_rpc(), req->rc.tag will not be properly initialized. However, trace_9p_client_res() ends up trying to print it out anyway before p9_client_rpc() finishes. Fix this issue by assigning default values to p9_fcall fields such as 'tag' and (just in case KMSAN unearths something new) 'id' during the tag allocation stage. Reported-and-tested-by: syzbot+ff14db38f56329ef68df@syzkaller.appspotmail.com Fixes: 348b59012e5c ("net/9p: Convert net/9p protocol dumps to tracepoints") Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru> Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com> Cc: stable@vger.kernel.org Message-ID: <20240408141039.30428-1-n.zhandarovich@fintech.ru> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2024-05-01netfs, 9p: Implement helpers for new write codeDavid Howells
Implement the helpers for the new write code in 9p. There's now an optional ->prepare_write() that allows the filesystem to set the parameters for the next write, such as maximum size and maximum segment count, and an ->issue_write() that is called to initiate an (asynchronous) write operation. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: Eric Van Hensbergen <ericvh@kernel.org> cc: Latchesar Ionkov <lucho@ionkov.net> cc: Dominique Martinet <asmadeus@codewreck.org> cc: Christian Schoenebeck <linux_oss@crudebyte.com> cc: v9fs@lists.linux.dev cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org
2024-02-129p: Fix read/write debug statements to report server replyDominique Martinet
Previous conversion to iov missed these debug statements which would now always print the requested size instead of the actual server reply. Write also added a loop in a much older commit but we didn't report these, while reads do report each iteration -- it's more coherent to keep reporting all requests to server so move that at the same time. Fixes: 7f02464739da ("9p: convert to advancing variant of iov_iter_get_pages_alloc()") Signed-off-by: Dominique Martinet <asmadeus@codewreck.org> Message-ID: <20240109-9p-rw-trace-v1-1-327178114257@codewreck.org>
2024-02-129p/trans_fd: remove Excess kernel-doc commentRandy Dunlap
Remove the "@req" kernel-doc description since there is not 'req' member in the struct p9_conn. Fixes one kernel-doc warning: trans_fd.c:133: warning: Excess struct member 'req' description in 'p9_conn' Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Latchesar Ionkov <lucho@ionkov.net> Cc: Dominique Martinet <asmadeus@codewreck.org> Cc: v9fs@lists.linux.dev Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: netdev@vger.kernel.org Reviewed-by: Simon Horman <horms@kernel.org> Message-ID: <20240212043341.4631-1-rdunlap@infradead.org> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2023-12-13net: 9p: avoid freeing uninit memory in p9pdu_vreadfFedor Pchelkin
If some of p9pdu_readf() calls inside case 'T' in p9pdu_vreadf() fails, the error path is not handled properly. *wnames or members of *wnames array may be left uninitialized and invalidly freed. Initialize *wnames to NULL in beginning of case 'T'. Initialize the first *wnames array element to NULL and nullify the failing *wnames element so that the error path freeing loop stops on the first NULL element and doesn't proceed further. Found by Linux Verification Center (linuxtesting.org). Fixes: ace51c4dd2f9 ("9p: add new protocol support code") Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru> Message-ID: <20231206200913.16135-1-pchelkin@ispras.ru> Cc: stable@vger.kernel.org Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2023-10-279p/net: fix possible memory leak in p9_check_errors()Hangyu Hua
When p9pdu_readf() is called with "s?d" attribute, it allocates a pointer that will store a string. But when p9pdu_readf() fails while handling "d" then this pointer will not be freed in p9_check_errors(). Fixes: 51a87c552dfd ("9p: rework client code to use new protocol support functions") Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com> Signed-off-by: Hangyu Hua <hbh25y@gmail.com> Message-ID: <20231027030302.11927-1-hbh25y@gmail.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2023-10-279p/net: xen: fix false positive printf format overflow warningDominique Martinet
Use the constant to make the compiler happy about this warning: net/9p/trans_xen.c: In function ‘xen_9pfs_front_changed’: net/9p/trans_xen.c:444:39: warning: ‘%d’ directive writing between 1 and 11 bytes into a region of size 8 [-Wformat-overflow=] 444 | sprintf(str, "ring-ref%d", i); | ^~ In function ‘xen_9pfs_front_init’, inlined from ‘xen_9pfs_front_changed’ at net/9p/trans_xen.c:516:8, inlined from ‘xen_9pfs_front_changed’ at net/9p/trans_xen.c:504:13: net/9p/trans_xen.c:444:30: note: directive argument in the range [-2147483644, 2147483646] 444 | sprintf(str, "ring-ref%d", i); | ^~~~~~~~~~~~ net/9p/trans_xen.c:444:17: note: ‘sprintf’ output between 10 and 20 bytes into a destination of size 16 444 | sprintf(str, "ring-ref%d", i); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ net/9p/trans_xen.c: In function ‘xen_9pfs_front_changed’: net/9p/trans_xen.c:450:45: warning: ‘%d’ directive writing between 1 and 11 bytes into a region of size 2 [-Wformat-overflow=] 450 | sprintf(str, "event-channel-%d", i); | ^~ In function ‘xen_9pfs_front_init’, inlined from ‘xen_9pfs_front_changed’ at net/9p/trans_xen.c:516:8, inlined from ‘xen_9pfs_front_changed’ at net/9p/trans_xen.c:504:13: net/9p/trans_xen.c:450:30: note: directive argument in the range [-2147483644, 2147483646] 450 | sprintf(str, "event-channel-%d", i); | ^~~~~~~~~~~~~~~~~~ net/9p/trans_xen.c:450:17: note: ‘sprintf’ output between 16 and 26 bytes into a destination of size 16 450 | sprintf(str, "event-channel-%d", i); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ There is no change in logic: there only are a constant number of rings, and there also already is a BUILD_BUG_ON that checks if that constant goes over 9 as anything bigger would no longer fit the event-channel-%d destination size. In theory having that size as part of the struct means it could be modified by another thread and makes the compiler lose track of possible values for 'i' here, using the constant directly here makes it work. Signed-off-by: Dominique Martinet <asmadeus@codewreck.org> Message-ID: <20231025103445.1248103-3-asmadeus@codewreck.org> Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com>
2023-10-269p: v9fs_listxattr: fix %s null argument warningDominique Martinet
W=1 warns about null argument to kprintf: In file included from fs/9p/xattr.c:12: In function ‘v9fs_xattr_get’, inlined from ‘v9fs_listxattr’ at fs/9p/xattr.c:142:9: include/net/9p/9p.h:55:2: error: ‘%s’ directive argument is null [-Werror=format-overflow=] 55 | _p9_debug(level, __func__, fmt, ##__VA_ARGS__) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Use an empty string instead of : - this is ok 9p-wise because p9pdu_vwritef serializes a null string and an empty string the same way (one '0' word for length) - since this degrades the print statements, add new single quotes for xattr's name delimter (Old: "file = (null)", new: "file = ''") Link: https://lore.kernel.org/r/20231008060138.517057-1-suhui@nfschina.com Suggested-by: Su Hui <suhui@nfschina.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org> Acked-by: Christian Schoenebeck <linux_oss@crudebyte.com> Message-ID: <20231025103445.1248103-2-asmadeus@codewreck.org>