Linux kernel ============ The Linux kernel is the core of any Linux operating system. It manages hardware, system resources, and provides the fundamental services for all other software. Quick Start ----------- * Report a bug: See Documentation/admin-guide/reporting-issues.rst * Get the latest kernel: https://kernel.org * Build the kernel: See Documentation/admin-guide/quickly-build-trimmed-linux.rst * Join the community: https://lore.kernel.org/ Essential Documentation ----------------------- All users should be familiar with: * Building requirements: Documentation/process/changes.rst * Code of Conduct: Documentation/process/code-of-conduct.rst * License: See COPYING Documentation can be built with make htmldocs or viewed online at: https://www.kernel.org/doc/html/latest/ Who Are You? ============ Find your role below: * New Kernel Developer - Getting started with kernel development * Academic Researcher - Studying kernel internals and architecture * Security Expert - Hardening and vulnerability analysis * Backport/Maintenance Engineer - Maintaining stable kernels * System Administrator - Configuring and troubleshooting * Maintainer - Leading subsystems and reviewing patches * Hardware Vendor - Writing drivers for new hardware * Distribution Maintainer - Packaging kernels for distros For Specific Users ================== New Kernel Developer -------------------- Welcome! Start your kernel development journey here: * Getting Started: Documentation/process/development-process.rst * Your First Patch: Documentation/process/submitting-patches.rst * Coding Style: Documentation/process/coding-style.rst * Build System: Documentation/kbuild/index.rst * Development Tools: Documentation/dev-tools/index.rst * Kernel Hacking Guide: Documentation/kernel-hacking/hacking.rst * Core APIs: Documentation/core-api/index.rst Academic Researcher ------------------- Explore the kernel's architecture and internals: * Researcher Guidelines: Documentation/process/researcher-guidelines.rst * Memory Management: Documentation/mm/index.rst * Scheduler: Documentation/scheduler/index.rst * Networking Stack: Documentation/networking/index.rst * Filesystems: Documentation/filesystems/index.rst * RCU (Read-Copy Update): Documentation/RCU/index.rst * Locking Primitives: Documentation/locking/index.rst * Power Management: Documentation/power/index.rst Security Expert --------------- Security documentation and hardening guides: * Security Documentation: Documentation/security/index.rst * LSM Development: Documentation/security/lsm-development.rst * Self Protection: Documentation/security/self-protection.rst * Reporting Vulnerabilities: Documentation/process/security-bugs.rst * CVE Procedures: Documentation/process/cve.rst * Embargoed Hardware Issues: Documentation/process/embargoed-hardware-issues.rst * Security Features: Documentation/userspace-api/seccomp_filter.rst Backport/Maintenance Engineer ----------------------------- Maintain and stabilize kernel versions: * Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst * Backporting Guide: Documentation/process/backporting.rst * Applying Patches: Documentation/process/applying-patches.rst * Subsystem Profile: Documentation/maintainer/maintainer-entry-profile.rst * Git for Maintainers: Documentation/maintainer/configure-git.rst System Administrator -------------------- Configure, tune, and troubleshoot Linux systems: * Admin Guide: Documentation/admin-guide/index.rst * Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst * Sysctl Tuning: Documentation/admin-guide/sysctl/index.rst * Tracing/Debugging: Documentation/trace/index.rst * Performance Security: Documentation/admin-guide/perf-security.rst * Hardware Monitoring: Documentation/hwmon/index.rst Maintainer ---------- Lead kernel subsystems and manage contributions: * Maintainer Handbook: Documentation/maintainer/index.rst * Pull Requests: Documentation/maintainer/pull-requests.rst * Managing Patches: Documentation/maintainer/modifying-patches.rst * Rebasing and Merging: Documentation/maintainer/rebasing-and-merging.rst * Development Process: Documentation/process/maintainer-handbooks.rst * Maintainer Entry Profile: Documentation/maintainer/maintainer-entry-profile.rst * Git Configuration: Documentation/maintainer/configure-git.rst Hardware Vendor --------------- Write drivers and support new hardware: * Driver API Guide: Documentation/driver-api/index.rst * Driver Model: Documentation/driver-api/driver-model/driver.rst * Device Drivers: Documentation/driver-api/infrastructure.rst * Bus Types: Documentation/driver-api/driver-model/bus.rst * Device Tree Bindings: Documentation/devicetree/bindings/ * Power Management: Documentation/driver-api/pm/index.rst * DMA API: Documentation/core-api/dma-api.rst Distribution Maintainer ----------------------- Package and distribute the kernel: * Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst * ABI Documentation: Documentation/ABI/README * Kernel Configuration: Documentation/kbuild/kconfig.rst * Module Signing: Documentation/admin-guide/module-signing.rst * Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst * Tainted Kernels: Documentation/admin-guide/tainted-kernels.rst Communication and Support ========================= * Mailing Lists: https://lore.kernel.org/ * IRC: #kernelnewbies on irc.oftc.net * Bugzilla: https://bugzilla.kernel.org/ * MAINTAINERS file: Lists subsystem maintainers and mailing lists * Email Clients: Documentation/process/email-clients.rst
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A previous commit added this helper, and had it terminate if false is
returned from the handler. However, that is completely opposite, it
should abort the loop if true is returned.
Fix this up by having io_wq_for_each_worker() keep iterating as long
as false is returned, and only abort if true is returned.
Cc: stable@vger.kernel.org
Fixes: 751eedc4b4b7 ("io_uring/io-wq: move worker lists to struct io_wq_acct")
Reported-by: Lewis Campbell <info@lewiscampbell.tech>
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_uring_validate_mmap_request() doesn't use its size_t sz argument, so
remove it.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
ctx->tcxt_list holds the tasks using this ring, and it's currently
protected by the normal ctx->uring_lock. However, this can cause a
circular locking issue, as reported by syzbot, where cancelations off
exec end up needing to remove an entry from this list:
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G L
------------------------------------------------------
syz.0.9999/12287 is trying to acquire lock:
ffff88805851c0a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_uring_del_tctx_node+0xf0/0x2c0 io_uring/tctx.c:179
but task is already holding lock:
ffff88802db5a2e0 (&sig->cred_guard_mutex){+.+.}-{4:4}, at: prepare_bprm_creds fs/exec.c:1360 [inline]
ffff88802db5a2e0 (&sig->cred_guard_mutex){+.+.}-{4:4}, at: bprm_execve+0xb9/0x1400 fs/exec.c:1733
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&sig->cred_guard_mutex){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:614 [inline]
__mutex_lock+0x187/0x1350 kernel/locking/mutex.c:776
proc_pid_attr_write+0x547/0x630 fs/proc/base.c:2837
vfs_write+0x27e/0xb30 fs/read_write.c:684
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #1 (sb_writers#3){.+.+}-{0:0}:
percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline]
percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
__sb_start_write include/linux/fs/super.h:19 [inline]
sb_start_write+0x4d/0x1c0 include/linux/fs/super.h:125
mnt_want_write+0x41/0x90 fs/namespace.c:499
open_last_lookups fs/namei.c:4529 [inline]
path_openat+0xadd/0x3dd0 fs/namei.c:4784
do_filp_open+0x1fa/0x410 fs/namei.c:4814
io_openat2+0x3e0/0x5c0 io_uring/openclose.c:143
__io_issue_sqe+0x181/0x4b0 io_uring/io_uring.c:1792
io_issue_sqe+0x165/0x1060 io_uring/io_uring.c:1815
io_queue_sqe io_uring/io_uring.c:2042 [inline]
io_submit_sqe io_uring/io_uring.c:2320 [inline]
io_submit_sqes+0xbf4/0x2140 io_uring/io_uring.c:2434
__do_sys_io_uring_enter io_uring/io_uring.c:3280 [inline]
__se_sys_io_uring_enter+0x2e0/0x2b60 io_uring/io_uring.c:3219
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&ctx->uring_lock){+.+.}-{4:4}:
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868
__mutex_lock_common kernel/locking/mutex.c:614 [inline]
__mutex_lock+0x187/0x1350 kernel/locking/mutex.c:776
io_uring_del_tctx_node+0xf0/0x2c0 io_uring/tctx.c:179
io_uring_clean_tctx+0xd4/0x1a0 io_uring/tctx.c:195
io_uring_cancel_generic+0x6ca/0x7d0 io_uring/cancel.c:646
io_uring_task_cancel include/linux/io_uring.h:24 [inline]
begin_new_exec+0x10ed/0x2440 fs/exec.c:1131
load_elf_binary+0x9f8/0x2d70 fs/binfmt_elf.c:1010
search_binary_handler fs/exec.c:1669 [inline]
exec_binprm fs/exec.c:1701 [inline]
bprm_execve+0x92e/0x1400 fs/exec.c:1753
do_execveat_common+0x510/0x6a0 fs/exec.c:1859
do_execve fs/exec.c:1933 [inline]
__do_sys_execve fs/exec.c:2009 [inline]
__se_sys_execve fs/exec.c:2004 [inline]
__x64_sys_execve+0x94/0xb0 fs/exec.c:2004
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Chain exists of:
&ctx->uring_lock --> sb_writers#3 --> &sig->cred_guard_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&sig->cred_guard_mutex);
lock(sb_writers#3);
lock(&sig->cred_guard_mutex);
lock(&ctx->uring_lock);
*** DEADLOCK ***
1 lock held by syz.0.9999/12287:
#0: ffff88802db5a2e0 (&sig->cred_guard_mutex){+.+.}-{4:4}, at: prepare_bprm_creds fs/exec.c:1360 [inline]
#0: ffff88802db5a2e0 (&sig->cred_guard_mutex){+.+.}-{4:4}, at: bprm_execve+0xb9/0x1400 fs/exec.c:1733
stack backtrace:
CPU: 0 UID: 0 PID: 12287 Comm: syz.0.9999 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2043
check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868
__mutex_lock_common kernel/locking/mutex.c:614 [inline]
__mutex_lock+0x187/0x1350 kernel/locking/mutex.c:776
io_uring_del_tctx_node+0xf0/0x2c0 io_uring/tctx.c:179
io_uring_clean_tctx+0xd4/0x1a0 io_uring/tctx.c:195
io_uring_cancel_generic+0x6ca/0x7d0 io_uring/cancel.c:646
io_uring_task_cancel include/linux/io_uring.h:24 [inline]
begin_new_exec+0x10ed/0x2440 fs/exec.c:1131
load_elf_binary+0x9f8/0x2d70 fs/binfmt_elf.c:1010
search_binary_handler fs/exec.c:1669 [inline]
exec_binprm fs/exec.c:1701 [inline]
bprm_execve+0x92e/0x1400 fs/exec.c:1753
do_execveat_common+0x510/0x6a0 fs/exec.c:1859
do_execve fs/exec.c:1933 [inline]
__do_sys_execve fs/exec.c:2009 [inline]
__se_sys_execve fs/exec.c:2004 [inline]
__x64_sys_execve+0x94/0xb0 fs/exec.c:2004
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff3a8b8f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff3a9a97038 EFLAGS: 00000246 ORIG_RAX: 000000000000003b
RAX: ffffffffffffffda RBX: 00007ff3a8de5fa0 RCX: 00007ff3a8b8f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000400
RBP: 00007ff3a8c13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff3a8de6038 R14: 00007ff3a8de5fa0 R15: 00007ff3a8f0fa28
</TASK>
Add a separate lock just for the tctx_list, tctx_lock. This can nest
under ->uring_lock, where necessary, and be used separately for list
manipulation. For the cancelation off exec side, this removes the
need to grab ->uring_lock, hence fixing the circular locking
dependency.
Reported-by: syzbot+b0e3b77ffaa8a4067ce5@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Allocate the overflowing CQE with GFP_NOWAIT instead of GFP_ATOMIC. This
changes causes allocations to fail earlier in out-of-memory situations,
rather than being deferred. Using GFP_ATOMIC allows a process to exceed
memory limits.
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220794
Signed-off-by: Alexandre Negrel <alexandre@negrel.dev>
Link: https://lore.kernel.org/io-uring/20251229201933.515797-1-alexandre@negrel.dev/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
__io_openat_prep() allocates a struct filename using getname(). However,
for the condition of the file being installed in the fixed file table as
well as having O_CLOEXEC flag set, the function returns early. At that
point, the request doesn't have REQ_F_NEED_CLEANUP flag set. Due to this,
the memory for the newly allocated struct filename is not cleaned up,
causing a memory leak.
Fix this by setting the REQ_F_NEED_CLEANUP for the request just after the
successful getname() call, so that when the request is torn down, the
filename will be cleaned up, along with other resources needing cleanup.
Reported-by: syzbot+00e61c43eb5e4740438f@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=00e61c43eb5e4740438f
Tested-by: syzbot+00e61c43eb5e4740438f@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Prithvi Tambewagh <activprithvi@gmail.com>
Fixes: b9445598d8c6 ("io_uring: openat directly into fixed fd table")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_import_kbuf() calculates nr_segs incorrectly when iov_offset is
non-zero after iov_iter_advance(). It doesn't account for the partial
consumption of the first bvec.
The problem comes when meet the following conditions:
1. Use UBLK_F_AUTO_BUF_REG feature of ublk.
2. The kernel will help to register the buffer, into the io uring.
3. Later, the ublk server try to send IO request using the registered
buffer in the io uring, to read/write to fuse-based filesystem, with
O_DIRECT.
>From a userspace perspective, the ublk server thread is blocked in the
kernel, and will see "soft lockup" in the kernel dmesg.
When ublk registers a buffer with mixed-size bvecs like [4K]*6 + [12K]
and a request partially consumes a bvec, the next request's nr_segs
calculation uses bvec->bv_len instead of (bv_len - iov_offset).
This causes fuse_get_user_pages() to loop forever because nr_segs
indicates fewer pages than actually needed.
Specifically, the infinite loop happens at:
fuse_get_user_pages()
-> iov_iter_extract_pages()
-> iov_iter_extract_bvec_pages()
Since the nr_segs is miscalculated, the iov_iter_extract_bvec_pages
returns when finding that i->nr_segs is zero. Then
iov_iter_extract_pages returns zero. However, fuse_get_user_pages does
still not get enough data/pages, causing infinite loop.
Example:
- Bvecs: [4K, 4K, 4K, 4K, 4K, 4K, 12K, ...]
- Request 1: 32K at offset 0, uses 6*4K + 8K of the 12K bvec
- Request 2: 32K at offset 32K
- iov_offset = 8K (8K already consumed from 12K bvec)
- Bug: calculates using 12K, not (12K - 8K) = 4K
- Result: nr_segs too small, infinite loop in fuse_get_user_pages.
Fix by accounting for iov_offset when calculating the first segment's
available length.
Fixes: b419bed4f0a6 ("io_uring/rsrc: ensure segments counts are correct on kbuf buffers")
Signed-off-by: huang-jl <huang-jl@deepseek.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Using min_wait, two timeouts are given:
1) The min_wait timeout, within which up to 'wait_nr' events are
waited for.
2) The overall long timeout, which is entered if no events are generated
in the min_wait window.
If the min_wait has expired, any event being posted must wake the task.
For SQPOLL, that isn't the case, as it won't trigger the io_has_work()
condition, as it will have already processed the task_work that happened
when an event was posted. This causes any event to trigger post the
min_wait to not always cause the waiting application to wakeup, and
instead it will wait until the overall timeout has expired. This can be
shown in a test case that has a 1 second min_wait, with a 5 second
overall wait, even if an event triggers after 1.5 seconds:
axboe@m2max-kvm /d/iouring-mre (master)> zig-out/bin/iouring
info: MIN_TIMEOUT supported: true, features: 0x3ffff
info: Testing: min_wait=1000ms, timeout=5s, wait_nr=4
info: 1 cqes in 5000.2ms
where the expected result should be:
axboe@m2max-kvm /d/iouring-mre (master)> zig-out/bin/iouring
info: MIN_TIMEOUT supported: true, features: 0x3ffff
info: Testing: min_wait=1000ms, timeout=5s, wait_nr=4
info: 1 cqes in 1500.3ms
When the min_wait timeout triggers, reset the number of completions
needed to wake the task. This should ensure that any future events will
wake the task, regardless of how many events it originally wanted to
wait for.
Reported-by: Tip ten Brink <tip@tenbrinkmeijs.com>
Cc: stable@vger.kernel.org
Fixes: 1100c4a2656d ("io_uring: add support for batch wait timeout")
Link: https://github.com/axboe/liburing/issues/1477
Signed-off-by: Jens Axboe <axboe@kernel.dk>
For some cases, the order in which the waitq entry list and head
writing happens is important, for others it doesn't really matter.
But it's somewhat confusing to have them spread out over the file.
Abstract out the nicely documented code in io_pollfree_wake() and
move it into a helper, and use that helper consistently rather than
having other call sites manually do the same thing. While at it,
correct a comment function name as well.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
buf->addr and buf->len reside in memory shared with userspace. They
should be written with WRITE_ONCE() to guarantee atomic stores and
prevent tearing or other unsafe compiler optimizations.
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Cc: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The struct io_uring_buf elements in a buffer ring are in a memory region
accessible from userspace. A malicious/buggy userspace program could
therefore write to them at any time, so they should be accessed with
READ_ONCE() in the kernel. Commit 98b6fa62c84f ("io_uring/kbuf: always
use READ_ONCE() to read ring provided buffer lengths") already switched
the reads of the len field to READ_ONCE(). Do the same for bid and addr.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Fixes: c7fb19428d67 ("io_uring: add support for ring mapped supplied buffers")
Cc: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When cloning with node replacements (IORING_REGISTER_DST_REPLACE),
destination entries after the cloned range are not copied over.
Add logic to copy them over to the new destination table.
Fixes: c1329532d5aa ("io_uring/rsrc: allow cloning with node replacements")
Cc: stable@vger.kernel.org
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The variable holds nodes from the destination ring's existing buffer
table. In io_clone_buffers(), the term "src" is used to refer to the
source ring.
Rename to node for clarity.
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Get rid of some redundant checks and move the src arg validation to
before the buffer table allocation, which simplifies error handling.
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The io_uring_queue_async_work tracepoint event stores an int rw field
that represents whether the work item is hashed. Rename it to "hashed"
and change its type to bool to more accurately reflect its value.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If a task has a pending signal when create_io_thread() is called,
copy_process() will return -ERESTARTNOINTR. io_should_retry_thread()
will request a retry of create_io_thread() up to WORKER_INIT_LIMIT = 3
times. If all retries fail, the io_uring request will fail with
ECANCELED.
Commit 3918315c5dc ("io-wq: backoff when retrying worker creation")
added a linear backoff to allow the thread to handle its signal before
the retry. However, a thread receiving frequent signals may get unlucky
and have a signal pending at every retry. Since the userspace task
doesn't control when it receives signals, there's no easy way for it to
prevent the create_io_thread() failure due to pending signals. The task
may also lack the information necessary to regenerate the canceled SQE.
So always retry the create_io_thread() on the ERESTART* errors,
analogous to what a fork() syscall would do. EAGAIN can occur due to
various persistent conditions such as exceeding RLIMIT_NPROC, so respect
the WORKER_INIT_LIMIT retry limit for EAGAIN errors.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When the core of io_uring was updated to handle completions
consistently and with fixed return codes, the POLL_REMOVE opcode
with updates got slightly broken. If a POLL_ADD is pending and
then POLL_REMOVE is used to update the events of that request, if that
update causes the POLL_ADD to now trigger, then that completion is lost
and a CQE is never posted.
Additionally, ensure that if an update does cause an existing POLL_ADD
to complete, that the completion value isn't always overwritten with
-ECANCELED. For that case, whatever io_poll_add() set the value to
should just be retained.
Cc: stable@vger.kernel.org
Fixes: 97b388d70b53 ("io_uring: handle completions in the core")
Reported-by: syzbot+641eec6b7af1f62f2b99@syzkaller.appspotmail.com
Tested-by: syzbot+641eec6b7af1f62f2b99@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull ntfs3 updates from Konstantin Komarov:
"New code:
- support timestamps prior to epoch
- do not overwrite uptodate pages
- disable readahead for compressed files
- setting of dummy blocksize to read boot_block when mounting
- the run_lock initialization when loading $Extend
- initialization of allocated memory before use
- support for the NTFS3_IOC_SHUTDOWN ioctl
- check for minimum alignment when performing direct I/O reads
- check for shutdown in fsync
Fixes:
- mount failure for sparse runs in run_unpack()
- use-after-free of sbi->options in cmp_fnames
- KMSAN uninit bug after failed mi_read in mi_format_new
- uninit error after buffer allocation by __getname()
- KMSAN uninit-value in ni_create_attr_list
- double free of sbi->options->nls and ownership of fc->fs_private
- incorrect vcn adjustments in attr_collapse_range()
- mode update when ACL can be reduced to mode
- memory leaks in add sub record
Changes:
- refactor code, updated terminology, spelling
- do not kmap pages in (de)compression code
- after ntfs_look_free_mft(), code that fails must put mft_inode
- default mount options for "acl" and "prealloc"
Replaced:
- use unsafe_memcpy() to avoid memcpy size warning
- ntfs_bio_pages with page cache for compressed files"
* tag 'ntfs3_for_6.19' of https://github.com/Paragon-Software-Group/linux-ntfs3: (26 commits)
fs/ntfs3: check for shutdown in fsync
fs/ntfs3: change the default mount options for "acl" and "prealloc"
fs/ntfs3: Prevent memory leaks in add sub record
fs/ntfs3: out1 also needs to put mi
fs/ntfs3: Fix spelling mistake "recommened" -> "recommended"
fs/ntfs3: update mode in xattr when ACL can be reduced to mode
fs/ntfs3: check minimum alignment for direct I/O
fs/ntfs3: implement NTFS3_IOC_SHUTDOWN ioctl
fs/ntfs3: correct attr_collapse_range when file is too fragmented
ntfs3: fix double free of sbi->options->nls and clarify ownership of fc->fs_private
fs/ntfs3: Initialize allocated memory before use
fs/ntfs3: remove ntfs_bio_pages and use page cache for compressed I/O
ntfs3: avoid memcpy size warning
fs/ntfs3: fix KMSAN uninit-value in ni_create_attr_list
ntfs3: init run lock for extend inode
ntfs: set dummy blocksize to read boot_block when mounting
fs/ntfs3: disable readahead for compressed files
ntfs3: Fix uninit buffer allocated by __getname()
ntfs3: fix uninit memory after failed mi_read in mi_format_new
ntfs3: fix use-after-free of sbi->options in cmp_fnames
...