summaryrefslogtreecommitdiff
path: root/io_uring
AgeCommit message (Collapse)Author
2025-01-15io_uring: Factor out a function to parse restrictionsJosh Triplett
Preparation for subsequent work on inherited restrictions. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/9bac2b4d1b9b9ab41c55ea3816021be847f354df.1736932318.git.josh@joshtriplett.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-15io_uring/register: cache old SQ/CQ head reading for copiesJens Axboe
The SQ and CQ ring heads are read twice - once for verifying that it's within bounds, and once inside the loops copying SQE and CQE entries. This is technically incorrect, in case the values could get modified in between verifying them and using them in the copy loop. While this won't lead to anything truly nefarious, it may cause longer loop times for the copies than expected. Read the ring head values once, and use the verified value in the copy loops. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-15io_uring/register: document io_register_resize_rings() shared mem usageJens Axboe
It can be a bit hard to tell which parts of io_register_resize_rings() are operating on shared memory, and which ones are not. And anything reading or writing to those regions should really use the read/write once primitives. Hence add those, ensuring sanity in how this memory is accessed, and helping document the shared nature of it. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-15io_uring/register: use stable SQ/CQ ring data during resizeJens Axboe
Normally the kernel would not expect an application to modify any of the data shared with the kernel during a resize operation, but of course the kernel cannot always assume good intent on behalf of the application. As part of resizing the rings, existing SQEs and CQEs are copied over to the new storage. Resizing uses the masks in the newly allocated shared storage to index the arrays, however it's possible that malicious userspace could modify these after they have been sanity checked. Use the validated and locally stored CQ and SQ ring sizing for masking to ensure the values are both stable and valid. Fixes: 79cfe9e59c2a ("io_uring/register: add IORING_REGISTER_RESIZE_RINGS") Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-14io_uring/rsrc: require cloned buffers to share accounting contextsJann Horn
When IORING_REGISTER_CLONE_BUFFERS is used to clone buffers from uring instance A to uring instance B, where A and B use different MMs for accounting, the accounting can go wrong: If uring instance A is closed before uring instance B, the pinned memory counters for uring instance B will be decremented, even though the pinned memory was originally accounted through uring instance A; so the MM of uring instance B can end up with negative locked memory. Cc: stable@vger.kernel.org Closes: https://lore.kernel.org/r/CAG48ez1zez4bdhmeGLEFxtbFADY4Czn3CV0u9d_TMcbvRA01bg@mail.gmail.com Fixes: 7cc2a6eadcd7 ("io_uring: add IORING_REGISTER_COPY_BUFFERS method") Signed-off-by: Jann Horn <jannh@google.com> Link: https://lore.kernel.org/r/20250114-uring-check-accounting-v1-1-42e4145aa743@google.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-14io_uring/rsrc: fixup io_clone_buffers() error handlingJens Axboe
Jann reports he can trigger a UAF if the target ring unregisters buffers before the clone operation is fully done. And additionally also an issue related to node allocation failures. Both of those stemp from the fact that the cleanup logic puts the buffers manually, rather than just relying on io_rsrc_data_free() doing it. Hence kill the manual cleanup code and just let io_rsrc_data_free() handle it, it'll put the nodes appropriately. Reported-by: Jann Horn <jannh@google.com> Fixes: 3597f2786b68 ("io_uring/rsrc: unify file and buffer resource tables") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-13io_uring: simplify the SQPOLL thread check when cancelling requestsBui Quang Minh
In io_uring_try_cancel_requests, we check whether sq_data->thread == current to determine if the function is called by the SQPOLL thread to do iopoll when IORING_SETUP_SQPOLL is set. This check can race with the SQPOLL thread termination. io_uring_cancel_generic is used in 2 places: io_uring_cancel_generic and io_ring_exit_work. In io_uring_cancel_generic, we have the information whether the current is SQPOLL thread already. And the SQPOLL thread never reaches io_ring_exit_work. So to avoid the racy check, this commit adds a boolean flag to io_uring_try_cancel_requests to determine if the caller is SQPOLL thread. Reported-by: syzbot+3c750be01dab672c513d@syzkaller.appspotmail.com Reported-by: Li Zetao <lizetao1@huawei.com> Reviewed-by: Li Zetao <lizetao1@huawei.com> Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/20250113160331.44057-1-minhquangbui99@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-11Merge tag 'io_uring-6.13-20250111' of git://git.kernel.dk/linuxLinus Torvalds
Pull io_uring fixes from Jens Axboe: - Fix for multishot timeout updates only using the updated value for the first invocation, not subsequent ones - Silence a false positive lockdep warning - Fix the eventfd signaling and putting RCU logic - Fix fault injected SQPOLL setup not clearing the task pointer in the error path - Fix local task_work looking at the SQPOLL thread rather than just signaling the safe variant. Again one of those theoretical issues, which should be closed up none the less. * tag 'io_uring-6.13-20250111' of git://git.kernel.dk/linux: io_uring: don't touch sqd->thread off tw add io_uring/sqpoll: zero sqd->thread on tctx errors io_uring/eventfd: ensure io_eventfd_signal() defers another RCU period io_uring: silence false positive warnings io_uring/timeout: fix multishot updates
2025-01-10io_uring: expose read/write attribute capabilityAnuj Gupta
After commit 9a213d3b80c0, we can pass additional attributes along with read/write. However, userspace doesn't know that. Add a new feature flag IORING_FEAT_RW_ATTR, to notify the userspace that the kernel has this ability. Signed-off-by: Anuj Gupta <anuj20.g@samsung.com> Reviewed-by: Li Zetao <lizetao1@huawei.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Tested-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/20241205062109.1788-1-anuj20.g@samsung.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-10io_uring: don't touch sqd->thread off tw addPavel Begunkov
With IORING_SETUP_SQPOLL all requests are created by the SQPOLL task, which means that req->task should always match sqd->thread. Since accesses to sqd->thread should be separately protected, use req->task in io_req_normal_work_add() instead. Note, in the eyes of io_req_normal_work_add(), the SQPOLL task struct is always pinned and alive, and sqd->thread can either be the task or NULL. It's only problematic if the compiler decides to reload the value after the null check, which is not so likely. Cc: stable@vger.kernel.org Cc: Bui Quang Minh <minhquangbui99@gmail.com> Reported-by: lizetao <lizetao1@huawei.com> Fixes: 78f9b61bd8e54 ("io_uring: wake SQPOLL task when task_work is added to an empty queue") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/1cbbe72cf32c45a8fee96026463024cd8564a7d7.1736541357.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-10io_uring/sqpoll: zero sqd->thread on tctx errorsPavel Begunkov
Syzkeller reports: BUG: KASAN: slab-use-after-free in thread_group_cputime+0x409/0x700 kernel/sched/cputime.c:341 Read of size 8 at addr ffff88803578c510 by task syz.2.3223/27552 Call Trace: <TASK> ... kasan_report+0x143/0x180 mm/kasan/report.c:602 thread_group_cputime+0x409/0x700 kernel/sched/cputime.c:341 thread_group_cputime_adjusted+0xa6/0x340 kernel/sched/cputime.c:639 getrusage+0x1000/0x1340 kernel/sys.c:1863 io_uring_show_fdinfo+0xdfe/0x1770 io_uring/fdinfo.c:197 seq_show+0x608/0x770 fs/proc/fd.c:68 ... That's due to sqd->task not being cleared properly in cases where SQPOLL task tctx setup fails, which can essentially only happen with fault injection to insert allocation errors. Cc: stable@vger.kernel.org Fixes: 1251d2025c3e1 ("io_uring/sqpoll: early exit thread if task_context wasn't allocated") Reported-by: syzbot+3d92cfcfa84070b0a470@syzkaller.appspotmail.com Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/efc7ec7010784463b2e7466d7b5c02c2cb381635.1736519461.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-10Merge tag 'vfs-6.13-rc7.fixes.2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs fixes from Christian Brauner: "afs: - Fix the maximum cell name length - Fix merge preference rule failure condition fuse: - Fix fuse_get_user_pages() so it doesn't risk misleading the caller to think pages have been allocated when they actually haven't - Fix direct-io folio offset and length calculation netfs: - Fix async direct-io handling - Fix read-retry for filesystems that don't provide a ->prepare_read() method vfs: - Prevent truncating 64-bit offsets to 32-bits in iomap - Fix memory barrier interactions when polling - Remove MNT_ONRB to fix concurrent modification of @mnt->mnt_flags leading to MNT_ONRB to not be raised and invalid access to a list member" * tag 'vfs-6.13-rc7.fixes.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: poll: kill poll_does_not_wait() sock_poll_wait: kill the no longer necessary barrier after poll_wait() io_uring_poll: kill the no longer necessary barrier after poll_wait() poll_wait: kill the obsolete wait_address check poll_wait: add mb() to fix theoretical race between waitqueue_active() and .poll() afs: Fix merge preference rule failure condition netfs: Fix read-retry for fs with no ->prepare_read() netfs: Fix kernel async DIO fs: kill MNT_ONRB iomap: avoid avoid truncating 64-bit offset to 32 bits afs: Fix the maximum cell name length fuse: Set *nbytesp=0 in fuse_get_user_pages on allocation failure fuse: fix direct io folio offset and length calculation
2025-01-10io_uring/rw: don't gate retry on completion contextJens Axboe
nvme multipath reports that they see spurious -EAGAIN bubbling back to userspace, which is caused by how they handle retries internally through a kworker. However, any data that needs preserving or importing for a read/write request has always been done so at prep time, and we can sanely skip this check. Reported-by: "Haeuptle, Michael" <michael.haeuptle@hpe.com> Link: https://lore.kernel.org/io-uring/DS7PR84MB31105C2C63CFA47BE8CBD6EE95102@DS7PR84MB3110.NAMPRD84.PROD.OUTLOOK.COM/ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-10io_uring/rw: handle -EAGAIN retry at IO completion timeJens Axboe
Rather than try and have io_read/io_write turn REQ_F_REISSUE into -EAGAIN, catch the REQ_F_REISSUE when the request is otherwise considered as done. This is saner as we know this isn't happening during an actual submission, and it removes the need to randomly check REQ_F_REISSUE after read/write submission. If REQ_F_REISSUE is set, __io_submit_flush_completions() will skip over this request in terms of posting a CQE, and the regular request cleaning will ensure that it gets reissued via io-wq. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-10io_uring/rw: use io_rw_recycle() from cleanup pathJens Axboe
Cleanup should always have the uring lock held, it's safe to recycle from here. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-10Merge branch 'vfs-6.14.poll' into vfs.fixesChristian Brauner
Bring in the fixes for __pollwait() and waitqueue_active() interactions. Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-01-10io_uring_poll: kill the no longer necessary barrier after poll_wait()Oleg Nesterov
Now that poll_wait() provides a full barrier we can remove smp_rmb() from io_uring_poll(). In fact I don't think smp_rmb() was correct, it can't serialize LOADs and STOREs. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Link: https://lore.kernel.org/r/20250107162730.GA18940@redhat.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-01-09Merge tag 'for-6.13-rc6-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "A few more fixes. Besides the one-liners in Btrfs there's fix to the io_uring and encoded read integration (added in this development cycle). The update to io_uring provides more space for the ongoing command that is then used in Btrfs to handle some cases. - io_uring and encoded read: - provide stable storage for io_uring command data - make a copy of encoded read ioctl call, reuse that in case the call would block and will be called again - properly initialize zlib context for hardware compression on s390 - fix max extent size calculation on filesystems with non-zoned devices - fix crash in scrub on crafted image due to invalid extent tree" * tag 'for-6.13-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: zlib: fix avail_in bytes for s390 zlib HW compression path btrfs: zoned: calculate max_extent_size properly on non-zoned setup btrfs: avoid NULL pointer dereference if no valid extent tree btrfs: don't read from userspace twice in btrfs_uring_encoded_read() io_uring: add io_uring_cmd_get_async_data helper io_uring/cmd: add per-op data to struct io_uring_cmd_data io_uring/cmd: rename struct uring_cache to io_uring_cmd_data
2025-01-09io_uring/eventfd: ensure io_eventfd_signal() defers another RCU periodJens Axboe
io_eventfd_do_signal() is invoked from an RCU callback, but when dropping the reference to the io_ev_fd, it calls io_eventfd_free() directly if the refcount drops to zero. This isn't correct, as any potential freeing of the io_ev_fd should be deferred another RCU grace period. Just call io_eventfd_put() rather than open-code the dec-and-test and free, which will correctly defer it another RCU grace period. Fixes: 21a091b970cd ("io_uring: signal registered eventfd to process deferred task work") Reported-by: Jann Horn <jannh@google.com> Cc: stable@vger.kernel.org Tested-by: Li Zetao <lizetao1@huawei.com> Reviewed-by: Li Zetao<lizetao1@huawei.com> Reviewed-by: Prasanna Kumar T S M <ptsm@linux.microsoft.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-07io_uring: silence false positive warningsPavel Begunkov
If we kill a ring and then immediately exit the task, we'll get cancellattion running by the task and a kthread in io_ring_exit_work. For DEFER_TASKRUN, we do want to limit it to only one entity executing it, however it's currently not an issue as it's protected by uring_lock. Silence lockdep assertions for now, we'll return to it later. Reported-by: syzbot+1bcb75613069ad4957fc@syzkaller.appspotmail.com Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/7e5f68281acb0f081f65fde435833c68a3b7e02f.1736257837.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-06io_uring/cmd: add per-op data to struct io_uring_cmd_dataJens Axboe
In case an op handler for ->uring_cmd() needs stable storage for user data, it can allocate io_uring_cmd_data->op_data and use it for the duration of the request. When the request gets cleaned up, uring_cmd will free it automatically. Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-06io_uring/cmd: rename struct uring_cache to io_uring_cmd_dataJens Axboe
In preparation for making this more generically available for ->uring_cmd() usage that needs stable command data, rename it and move it to io_uring/cmd.h instead. Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-04io_uring/timeout: fix multishot updatesPavel Begunkov
After update only the first shot of a multishot timeout request adheres to the new timeout value while all subsequent retries continue to use the old value. Don't forget to update the timeout stored in struct io_timeout_data. Cc: stable@vger.kernel.org Fixes: ea97f6c8558e8 ("io_uring: add support for multishot timeouts") Reported-by: Christian Mazakas <christian.mazakas@gmail.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/e6516c3304eb654ec234cfa65c88a9579861e597.1736015288.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-03io_uring/rsrc: simplify the bvec iter count calculationBui Quang Minh
As we don't use iov_iter_advance() but our own logic in io_import_fixed(), we can remove the logic that over-sets the iter's count to len + offset then adjusts it later to len. This helps to make the code cleaner. Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com> Link: https://lore.kernel.org/r/20250103150412.12549-1-minhquangbui99@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-03io_uring/kbuf: use pre-committed buffer address for non-pollable fileJens Axboe
For non-pollable files, buffer ring consumption will commit upfront. This is fine, but io_ring_buffer_select() will return the address of the buffer after having committed it. For incrementally consumed buffers, this is incorrect as it will modify the buffer address. Store the pre-committed value and return that. If that isn't done, then the initial part of the buffer is not used and the application will correctly assume the content arrived at the start of the userspace buffer, but the kernel will have put it later in the buffer. Or it can cause a spurious -EFAULT returned in the CQE, depending on the buffer size. As bounds are suitably checked for doing the actual IO, no adverse side effects are possible - it's just a data misplacement within the existing buffer. Reported-by: Gwendal Fernet <gwendalfernet@gmail.com> Cc: stable@vger.kernel.org Fixes: ae98dbf43d75 ("io_uring/kbuf: add support for incremental buffer consumption") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-02io_uring/net: always initialize kmsg->msg.msg_inq upfrontJens Axboe
syzbot reports that ->msg_inq may get used uinitialized from the following path: BUG: KMSAN: uninit-value in io_recv_buf_select io_uring/net.c:1094 [inline] BUG: KMSAN: uninit-value in io_recv+0x930/0x1f90 io_uring/net.c:1158 io_recv_buf_select io_uring/net.c:1094 [inline] io_recv+0x930/0x1f90 io_uring/net.c:1158 io_issue_sqe+0x420/0x2130 io_uring/io_uring.c:1740 io_queue_sqe io_uring/io_uring.c:1950 [inline] io_req_task_submit+0xfa/0x1d0 io_uring/io_uring.c:1374 io_handle_tw_list+0x55f/0x5c0 io_uring/io_uring.c:1057 tctx_task_work_run+0x109/0x3e0 io_uring/io_uring.c:1121 tctx_task_work+0x6d/0xc0 io_uring/io_uring.c:1139 task_work_run+0x268/0x310 kernel/task_work.c:239 io_run_task_work+0x43a/0x4a0 io_uring/io_uring.h:343 io_cqring_wait io_uring/io_uring.c:2527 [inline] __do_sys_io_uring_enter io_uring/io_uring.c:3439 [inline] __se_sys_io_uring_enter+0x204f/0x4ce0 io_uring/io_uring.c:3330 __x64_sys_io_uring_enter+0x11f/0x1a0 io_uring/io_uring.c:3330 x64_sys_call+0xce5/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:427 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f and it is correct, as it's never initialized upfront. Hence the first submission can end up using it uninitialized, if the recv wasn't successful and the networking stack didn't honor ->msg_get_inq being set and filling in the output value of ->msg_inq as requested. Set it to 0 upfront when it's allocated, just to silence this KMSAN warning. There's no side effect of using it uninitialized, it'll just potentially cause the next receive to use a recv value hint that's not accurate. Fixes: c6f32c7d9e09 ("io_uring/net: get rid of ->prep_async() for receive side") Reported-by: syzbot+068ff190354d2f74892f@syzkaller.appspotmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-30io_uring: ensure io_queue_deferred() is out-of-lineJens Axboe
This is not the hot path, it's a slow path. Yet the locking for it is in the hot path, and __cold does not prevent it from being inlined. Move the locking to the function itself, and mark it noinline as well to avoid it polluting the icache of the hot path. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-30io_uring/timeout: flush timeouts outside of the timeout lockJens Axboe
syzbot reports that a recent fix causes nesting issues between the (now) raw timeoutlock and the eventfd locking: ============================= [ BUG: Invalid wait context ] 6.13.0-rc4-00080-g9828a4c0901f #29 Not tainted ----------------------------- kworker/u32:0/68094 is trying to lock: ffff000014d7a520 (&ctx->wqh#2){..-.}-{3:3}, at: eventfd_signal_mask+0x64/0x180 other info that might help us debug this: context-{5:5} 6 locks held by kworker/u32:0/68094: #0: ffff0000c1d98148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x4e8/0xfc0 #1: ffff80008d927c78 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x53c/0xfc0 #2: ffff0000c59bc3d8 (&ctx->completion_lock){+.+.}-{3:3}, at: io_kill_timeouts+0x40/0x180 #3: ffff0000c59bc358 (&ctx->timeout_lock){-.-.}-{2:2}, at: io_kill_timeouts+0x48/0x180 #4: ffff800085127aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x8/0x38 #5: ffff800085127aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x8/0x38 stack backtrace: CPU: 7 UID: 0 PID: 68094 Comm: kworker/u32:0 Not tainted 6.13.0-rc4-00080-g9828a4c0901f #29 Hardware name: linux,dummy-virt (DT) Workqueue: iou_exit io_ring_exit_work Call trace: show_stack+0x1c/0x30 (C) __dump_stack+0x24/0x30 dump_stack_lvl+0x60/0x80 dump_stack+0x14/0x20 __lock_acquire+0x19f8/0x60c8 lock_acquire+0x1a4/0x540 _raw_spin_lock_irqsave+0x90/0xd0 eventfd_signal_mask+0x64/0x180 io_eventfd_signal+0x64/0x108 io_req_local_work_add+0x294/0x430 __io_req_task_work_add+0x1c0/0x270 io_kill_timeout+0x1f0/0x288 io_kill_timeouts+0xd4/0x180 io_uring_try_cancel_requests+0x2e8/0x388 io_ring_exit_work+0x150/0x550 process_one_work+0x5e8/0xfc0 worker_thread+0x7ec/0xc80 kthread+0x24c/0x300 ret_from_fork+0x10/0x20 because after the preempt-rt fix for the timeout lock nesting inside the io-wq lock, we now have the eventfd spinlock nesting inside the raw timeout spinlock. Rather than play whack-a-mole with other nesting on the timeout lock, split the deletion and killing of timeouts so queueing the task_work for the timeout cancelations can get done outside of the timeout lock. Reported-by: syzbot+b1fc199a40b65d601b65@syzkaller.appspotmail.com Fixes: 020b40f35624 ("io_uring: make ctx->timeout_lock a raw spinlock") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-28io_uring/rw: fix downgraded mshot readPavel Begunkov
The io-wq path can downgrade a multishot request to oneshot mode, however io_read_mshot() doesn't handle that and would still post multiple CQEs. That's not allowed, because io_req_post_cqe() requires stricter context requirements. The described can only happen with pollable files that don't support FMODE_NOWAIT, which is an odd combination, so if even allowed it should be fairly rare. Cc: stable@vger.kernel.org Reported-by: chase xd <sl1589472800@gmail.com> Fixes: bee1d5becdf5b ("io_uring: disable io-wq execution of multishot NOWAIT requests") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/c5c8c4a50a882fd581257b81bf52eee260ac29fd.1735407848.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-27io_uring/rw: always clear ->bytes_done on io_async_rw setupJens Axboe
A previous commit mistakenly moved the clearing of the in-progress byte count into the section that's dependent on having a cached iovec or not, but it should be cleared for any IO. If not, then extra bytes may be added at IO completion time, causing potentially weird behavior like over-reporting the amount of IO done. Fixes: d7f11616edf5 ("io_uring/rw: Allocate async data through helper") Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202412271132.a09c3500-lkp@intel.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-27io_uring/rw: use NULL for rw->free_iovec assigmentJens Axboe
It's a pointer, don't use 0 for that. sparse throws a warning for that, as the kernel test robot noticed. Fixes: d7f11616edf5 ("io_uring/rw: Allocate async data through helper") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202412180253.YML3qN4d-lkp@intel.com/ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-27io_uring/rw: don't mask in f_iocb_flagsJens Axboe
A previous commit changed overwriting kiocb->ki_flags with ->f_iocb_flags with masking it in. This breaks for retry situations, where we don't necessarily want to retain previously set flags, like IOCB_NOWAIT. The use case needs IOCB_HAS_METADATA to be persistent, but the change makes all flags persistent, which is an issue. Add a request flag to track whether the request has metadata or not, as that is persistent across issues. Fixes: 59a7d12a7fb5 ("io_uring: introduce attributes for read/write and PI support") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-27io_uring/msg_ring: Drop custom destructorGabriel Krisman Bertazi
kfree can handle slab objects nowadays. Drop the extra callback and just use kfree. Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de> Link: https://lore.kernel.org/r/20241216204615.759089-10-krisman@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-27io_uring: Move old async data allocation helper to headerGabriel Krisman Bertazi
There are two remaining uses of the old async data allocator that do not rely on the alloc cache. I don't want to make them use the new allocator helper because that would require a if(cache) check, which will result in dead code for the cached case (for callers passing a cache, gcc can't prove the cache isn't NULL, and will therefore preserve the check. Since this is an inline function and just a few lines long, keep a second helper to deal with cases where we don't have an async data cache. No functional change intended here. This is just moving the helper around and making it inline. Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de> Link: https://lore.kernel.org/r/20241216204615.759089-9-krisman@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-27io_uring/rw: Allocate async data through helperGabriel Krisman Bertazi
This abstract away the cache details. Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de> Link: https://lore.kernel.org/r/20241216204615.759089-8-krisman@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-27io_uring/net: Allocate msghdr async data through helperGabriel Krisman Bertazi
This abstracts away the cache details. Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de> Link: https://lore.kernel.org/r/20241216204615.759089-7-krisman@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-27io_uring/uring_cmd: Allocate async data through generic helperGabriel Krisman Bertazi
This abstracts away the cache details and simplify the code. Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de> Link: https://lore.kernel.org/r/20241216204615.759089-6-krisman@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-27io_uring/poll: Allocate apoll with generic alloc_cache helperGabriel Krisman Bertazi
This abstracts away the cache details to simplify the code. Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de> Link: https://lore.kernel.org/r/20241216204615.759089-5-krisman@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-27io_uring/futex: Allocate ifd with generic alloc_cache helperGabriel Krisman Bertazi
Instead of open-coding the allocation, use the generic alloc_cache helper. Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de> Link: https://lore.kernel.org/r/20241216204615.759089-4-krisman@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-27io_uring: Add generic helper to allocate async dataGabriel Krisman Bertazi
This helper replaces io_alloc_async_data by using the folded allocation. Do it in a header to allow the compiler to decide whether to inline. Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de> Link: https://lore.kernel.org/r/20241216204615.759089-3-krisman@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-26io_uring/sqpoll: fix sqpoll error handling racesPavel Begunkov
BUG: KASAN: slab-use-after-free in __lock_acquire+0x370b/0x4a10 kernel/locking/lockdep.c:5089 Call Trace: <TASK> ... _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline] try_to_wake_up+0xb5/0x23c0 kernel/sched/core.c:4205 io_sq_thread_park+0xac/0xe0 io_uring/sqpoll.c:55 io_sq_thread_finish+0x6b/0x310 io_uring/sqpoll.c:96 io_sq_offload_create+0x162/0x11d0 io_uring/sqpoll.c:497 io_uring_create io_uring/io_uring.c:3724 [inline] io_uring_setup+0x1728/0x3230 io_uring/io_uring.c:3806 ... Kun Hu reports that the SQPOLL creating error path has UAF, which happens if io_uring_alloc_task_context() fails and then io_sq_thread() manages to run and complete before the rest of error handling code, which means io_sq_thread_finish() is looking at already killed task. Note that this is mostly theoretical, requiring fault injection on the allocation side to trigger in practice. Cc: stable@vger.kernel.org Reported-by: Kun Hu <huk23@m.fudan.edu.cn> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/0f2f1aa5729332612bd01fe0f2f385fd1f06ce7c.1735231717.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-23io_uring: Fold allocation into alloc_cache helperGabriel Krisman Bertazi
The allocation paths that use alloc_cache duplicate the same code pattern, sometimes in a quite convoluted way. Fold the allocation into the cache code itself, making it just an allocator function, and keeping the cache policy invisible to callers. Another justification for doing this, beyond code simplicity, is that it makes it trivial to test the impact of disabling the cache and using slab directly, which I've used for slab improvement experiments. One relevant detail is that we provide a callback to optionally initialize memory only when we actually reach slab. This allows us to avoid blindly executing the allocation with GFP_ZERO and only clean fields when they matter. Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de> Link: https://lore.kernel.org/r/20241216204615.759089-2-krisman@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-23io_uring: prevent reg-wait speculationsPavel Begunkov
With *ENTER_EXT_ARG_REG instead of passing a user pointer with arguments for the waiting loop the user can specify an offset into a pre-mapped region of memory, in which case the [offset, offset + sizeof(io_uring_reg_wait)) will be intepreted as the argument. As we address a kernel array using a user given index, it'd be a subject to speculation type of exploits. Use array_index_nospec() to prevent that. Make sure to pass not the full region size but truncate by the maximum offset allowed considering the structure size. Fixes: d617b3147d54c ("io_uring: restore back registered wait arguments") Fixes: aa00f67adc2c0 ("io_uring: add support for fixed wait regions") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/1e3d9da7c43d619de7bcf41d1cd277ab2688c443.1733694126.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-23io_uring: don't vmap single page regionsPavel Begunkov
When io_check_coalesce_buffer() meets a single page buffer it bails out and tells that it can be coalesced. That's fine for registered buffers as io_coalesce_buffer() wouldn't change anything, but the region code now uses the function to decided on whether to vmap the buffer or not. Report that a single page buffer is trivially coalescable and let io_sqe_buffer_register() to filter them. Fixes: c4d0ac1c1567 ("io_uring/memmap: optimise single folio regions") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/cb83e053f318857068447d40c95becebcd8aeced.1733689833.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-23io_uring: clean up io_prep_rw_setup()David Wei
Remove unnecessary call to iov_iter_save_state() in io_prep_rw_setup() as io_import_iovec() already does this. Then the result from io_import_iovec() can be returned directly. Signed-off-by: David Wei <dw@davidwei.uk> Reviewed-by: Anuj Gupta <anuj20.g@samsung.com> Tested-by: Li Zetao <lizetao1@huawei.com> Link: https://lore.kernel.org/r/20241207004144.783631-1-dw@davidwei.uk Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-23io_uring/kbuf: fix unintentional sign extension on shift of reg.bgidColin Ian King
Shifting reg.bgid << IORING_OFF_PBUF_SHIFT results in a promotion from __u16 to a 32 bit signed integer, this is then sign extended to a 64 bit unsigned long on 64 bit architectures. If reg.bgid is greater than 0x7fff then this leads to a sign extended result where all the upper 32 bits of mmap_offset are set to 1. Fix this by casting reg.bgid to the same type as mmap_offset before performing the shift. Fixes: ef62de3c4ad5 ("io_uring/kbuf: use region api for pbuf rings") Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Link: https://lore.kernel.org/r/20241204153923.401674-1-colin.i.king@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-23io_uring: introduce attributes for read/write and PI supportAnuj Gupta
Add the ability to pass additional attributes along with read/write. Application can prepare attibute specific information and pass its address using the SQE field: __u64 attr_ptr; Along with setting a mask indicating attributes being passed: __u64 attr_type_mask; Overall 64 attributes are allowed and currently one attribute 'IORING_RW_ATTR_FLAG_PI' is supported. With PI attribute, userspace can pass following information: - flags: integrity check flags IO_INTEGRITY_CHK_{GUARD/APPTAG/REFTAG} - len: length of PI/metadata buffer - addr: address of metadata buffer - seed: seed value for reftag remapping - app_tag: application defined 16b value Process this information to prepare uio_meta_descriptor and pass it down using kiocb->private. PI attribute is supported only for direct IO. Signed-off-by: Anuj Gupta <anuj20.g@samsung.com> Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> Link: https://lore.kernel.org/r/20241128112240.8867-7-anuj20.g@samsung.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-23io_uring/memmap: unify io_uring mmap'ing codePavel Begunkov
All mapped memory is now backed by regions and we can unify and clean up io_region_validate_mmap() and io_uring_mmap(). Extract a function looking up a region, the rest of the handling should be generic and just needs the region. There is one more ring type specific code, i.e. the mmaping size truncation quirk for IORING_OFF_[S,C]Q_RING, which is left as is. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/f5e1eda1562bfd34276de07465525ae5f10e1e84.1732886067.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-23io_uring/kbuf: use region api for pbuf ringsPavel Begunkov
Convert internal parts of the provided buffer ring managment to the region API. It's the last non-region mapped ring we have, so it also kills a bunch of now unused memmap.c helpers. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/6c40cf7beaa648558acd4d84bc0fb3279a35d74b.1732886067.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-23io_uring/kbuf: remove pbuf ring refcountingPavel Begunkov
struct io_buffer_list refcounting was needed for RCU based sync with mmap, now we can kill it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/4a9cc54bf0077bb2bf2f3daf917549ddd41080da.1732886067.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>