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13 daysio_uring/rw: fix missing ERESTARTSYS conversion in read pathsYitang Yang1-17/+25
commit ab05caca123c6d0b41850b7c05b246e4dca4a770 upstream. Both read and write may receive internal restart error codes from the filesystem layer and should be converted to -EINTR. However, when multishot read support was added, the error code normalization was lost for both io_read() and io_read_mshot(). Extract the conversion into io_fixup_restart_res() and apply it in all three locations: io_rw_done(), io_read(), and io_read_mshot(). Fixes: a08d195b586a ("io_uring/rw: split io_read() into a helper") Cc: stable@vger.kernel.org Signed-off-by: Yitang Yang <yi1tang.yang@gmail.com> Link: https://patch.msgid.link/20260722124551.130563-1-yi1tang.yang@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-07-24io_uring/rw: preserve partial result for iopollMichael Wigham1-6/+6
[ Upstream commit c554246ff4c68abf71b61a89c6e39d3cf94f523e ] A partial read will store the completed byte count in io->bytes_done. The regular completion path applies io_fixup_rw_res() so that, when the following operation reaches EOF, the number of bytes already read is returned. The iopoll completion path does not apply this fixup to the return value and can return zero instead. Use the fixup result when updating the CQE, and the raw result for the reissue check. Cc: stable@vger.kernel.org Fixes: 4d9cb92ca41d ("io_uring/rw: fix short rw error handling") Signed-off-by: Michael Wigham <michael@wigham.net> Link: https://patch.msgid.link/20260613225240.34032-1-michael@wigham.net Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-07-24io_uring/rw: ensure reissue path is correctly handled for IOPOLLJens Axboe1-4/+3
[ Upstream commit bcb0fda3c2da9fe4721d3e73d80e778c038e7d27 ] The IOPOLL path posts CQEs when the io_kiocb is marked as completed, so it cannot rely on the usual retry that non-IOPOLL requests do for read/write requests. If -EAGAIN is received and the request should be retried, go through the normal completion path and let the normal flush logic catch it and reissue it, like what is done for !IOPOLL reads or writes. Fixes: d803d123948f ("io_uring/rw: handle -EAGAIN retry at IO completion time") Reported-by: John Garry <john.g.garry@oracle.com> Link: https://lore.kernel.org/io-uring/2b43ccfa-644d-4a09-8f8f-39ad71810f41@oracle.com/ Signed-off-by: Jens Axboe <axboe@kernel.dk> Stable-dep-of: c554246ff4c6 ("io_uring/rw: preserve partial result for iopoll") Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-07-18io_uring/io-wq: re-check IO_WQ_BIT_EXIT for each linked work itemRunyu Xiao1-1/+1
commit 29bef9934b2521f787bb15dd1985d4c0d12ae02a upstream. commit 10dc95939817 ("io_uring/io-wq: check IO_WQ_BIT_EXIT inside work run loop") fixed the obvious case where io_worker_handle_work() took one exit-bit snapshot before draining pending work, but the fix stops one level too early. io_worker_handle_work() now re-checks IO_WQ_BIT_EXIT in its outer work run loop, yet it still snapshots that bit once before processing a whole dependent linked-work chain. If io_wq_exit_start() sets IO_WQ_BIT_EXIT after the first linked item has started, the remaining linked items can still reuse stale do_kill = false, skip IO_WQ_WORK_CANCEL, and continue running after exit has begun. Move the check further inside, so it covers linked items too. Note: this is a syzbot special as it loves setting up tons of slow linked work on weird devices like msr that take forever to read, and immediately close the ring. Exit then takes a long time. Fixes: 10dc95939817 ("io_uring/io-wq: check IO_WQ_BIT_EXIT inside work run loop") Cc: stable@vger.kernel.org Signed-off-by: Runyu Xiao <runyu.xiao@seu.edu.cn> Link: https://patch.msgid.link/20260527172203.2043962-1-runyu.xiao@seu.edu.cn Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-07-04io_uring/net: Avoid msghdr on op_connect/op_bind async dataGabriel Krisman Bertazi2-20/+20
[ Upstream commit 3979840cd858f30f43ea9f4e7f7f1f56de82d698 ] This fixes a memory leak due to the lack of the cleanup hook for the iovec. The stable backport differs from upstream by dropping the io_connect_bpf_populate hunk, which didn't exist at the time and by fixing the merge conflict due to the introduction of io_bind_file_create and by using the older async_data allocation API. Both IORING_OP_CONNECT and IORING_OP_BIND reuse the msghdr object just to store the sockaddr. Beyond allocating a much larger object than needed, msghdr can also wrap an iovec, which will be recycled unnecessarily. This uses the sockaddr directly. Cc: stable@vger.kernel.org Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de> Link: https://patch.msgid.link/20260602215327.1885109-2-krisman@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-06-19io_uring/wait: fix min_timeout behaviorChristian A. Ehrhardt1-1/+1
Commit 29fe1bd01b99714f3136f922230a643c2742cda9 upstream. The wakeup condition if a min timeout is present and has expired is that at least _one_ CQE was posted. Thus set the cq_tail target to ->cq_min_tail + 1. Without this commit a spurious wakeup can result in a premature wakeup because io_should_wake() will return true even if _no_ CQE was posted at all. Cc: Tip ten Brink <tip@tenbrinkmeijs.com> Fixes: e15cb2200b93 ("io_uring: fix min_wait wakeups for SQPOLL") Cc: stable@vger.kernel.org Signed-off-by: Christian A. Ehrhardt <lk@c--e.de> Link: https://patch.msgid.link/20260606201120.1441447-1-lk@c--e.de Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-06-19io_uring/kbuf: don't truncate end buffer for bundlesJens Axboe1-1/+0
Commit 70f4886bcbb929e88038c8807f1daf7fc587ae7c upstream. If buffers have been peeked for a bundle receive, the kernel will truncate the end buffer, if the available length is shorter than the buffer itself. This is unnecessary, as applications iterating bundle receives must always use the minimum size of the buffer length and the remaining number of bytes in the bundle. The examples in liburing do that as well, eg examples/proxy.c. If the kernel does truncate this buffer AND the current transfer fails, then the buffer will be left with a smaller size than what is otherwise available. Just remove the buffer truncation, as it's not necessary in the first place. Link: https://lore.kernel.org/io-uring/CAAEr8jbY60noGj1fw_k91UJRBkyiRVoS6=nLhZ7Svwidjn4CAA@mail.gmail.com/ Reported-by: Federico Brasili <federico.brasili@gmail.com> Cc: stable@vger.kernel.org Fixes: 35c8711c8fc4 ("io_uring/kbuf: add helpers for getting/peeking multiple buffers") Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-06-19io_uring/net: inherit IORING_CQE_F_BUF_MORE across bundle recv retriesClément Léger1-1/+2
commit ed46f39c47eb5530a9c161481a2080d3a869cfaf upstream. When a bundle recv retries inside io_recv_finish(), the merge logic OR the saved cflags from the previous iteration with the cflags returned by the new iteration: cflags = req->cqe.flags | (cflags & CQE_F_MASK); Bits listed in CQE_F_MASK are inherited from the new iteration, and all other bits (notably IORING_CQE_F_BUFFER and the buffer ID) come from the saved cflags. Before this change CQE_F_MASK covered only IORING_CQE_F_SOCK_NONEMPTY and IORING_CQE_F_MORE. When using provided buffer rings (IOU_PBUF_RING_INC) with incremental mode, and bundle recv, io_kbuf_inc_commit() can leave the head ring entry partially consumed, __io_put_kbufs() then sets IORING_CQE_F_BUF_MORE on the returned cflags so userspace knows the buffer ID will be reused for subsequent completions. Because IORING_CQE_F_BUF_MORE was not in CQE_F_MASK, the merge above silently dropped it whenever the final retry iteration partially consumed the buffer, and the subsequent req->cqe.flags = cflags & ~CQE_F_MASK save would have left a stale IORING_CQE_F_BUF_MORE in the carried-over cflags had one been present. Userspace would then wrongfully advance it ring head past an entry the kernel still uses. Add IORING_CQE_F_BUF_MORE to CQE_F_MASK so it is both inherited from the new iteration into the user-visible CQE and stripped from the saved cflags between iterations. Cc: stable@vger.kernel.org Signed-off-by: Clément Léger <cleger@meta.com> Assisted-by: Claude:claude-opus-4.6 Fixes: ae98dbf43d75 ("io_uring/kbuf: add support for incremental buffer consumption") Link: https://patch.msgid.link/20260604160715.2482972-1-cleger@meta.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-06-09remove pointless includes of <linux/fdtable.h>Al Viro1-1/+0
[ Upstream commit be5498cac2ddb112c5bd7433d5e834a1a2493427 ] some of those used to be needed, some had been cargo-culted for no reason... Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Stable-dep-of: ea5fe6a73ca5 ("net/handshake: Drain pending requests at net namespace exit") Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-06-01io_uring/net: punt IORING_OP_BIND async if it needs file createJens Axboe1-1/+25
[ Upstream commit ccd25890f73c082fe2657ed227b497d6ac5fdc40 ] For two reasons: 1) An opcode cannot block inside io_uring_enter() doing submissions, as it'll stall the submission side pipeline. 2) Ending up in sb_start_write() -> __sb_start_write() -> percpu_down_read_freezable() introduces a new lockdep edge, which it correctly complains about. Check if the socket type is AF_UNIX and has a non-empty pathname. If it does, mark it REQ_F_FORCE_ASYNC to punt the submission to io-wq rather than attempt to do it inline. Fixes: 7481fd93fa0a ("io_uring: Introduce IORING_OP_BIND") Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-06-01io_uring/waitid: clear waitid info before copying it to userspaceHeechan Kang1-0/+1
commit 93d93f5f8da791e98159795c6ef683f45bd95d13 upstream. IORING_OP_WAITID stores its result fields in struct io_waitid::info and later copies them to userspace siginfo. The prep path initializes the request arguments, but it does not initialize info itself. If the wait operation completes without reporting a child event, the common wait code can return without writing wo_info. In that case io_waitid_finish() still copies iw->info to userspace, exposing stale bytes from the reused io_kiocb command storage. Clear the result storage during prep so the io_uring path matches the regular waitid syscall, which uses a zero-initialized struct waitid_info. Fixes: f31ecf671ddc ("io_uring: add IORING_OP_WAITID support") Cc: stable@vger.kernel.org # 6.7+ Signed-off-by: Heechan Kang <gganji11@naver.com> Link: https://patch.msgid.link/20260516184709.852814-1-gganji11@naver.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-23io-wq: check that the predecessor is hashed in io_wq_remove_pending()Nicholas Carlini1-1/+2
commit d6a2d7b04b5a093021a7a0e2e69e9d5237dfa8cc upstream. io_wq_remove_pending() needs to fix up wq->hash_tail[] if the cancelled work was the tail of its hash bucket. When doing this, it checks whether the preceding entry in acct->work_list has the same hash value, but never checks that the predecessor is hashed at all. io_get_work_hash() is simply atomic_read(&work->flags) >> IO_WQ_HASH_SHIFT, and the hash bits are never set for non-hashed work, so it returns 0. Thus, when a hashed bucket-0 work is cancelled while a non-hashed work is its list predecessor, the check spuriously passes and a pointer to the non-hashed io_kiocb is stored in wq->hash_tail[0]. Because non-hashed work is dequeued via the fast path in io_get_next_work(), which never touches hash_tail[], the stale pointer is never cleared. Therefore, after the non-hashed io_kiocb completes and is freed back to req_cachep, wq->hash_tail[0] is a dangling pointer. The io_wq is per-task (tctx->io_wq) and survives ring open/close, so the dangling pointer persists for the lifetime of the task; the next hashed bucket-0 enqueue dereferences it in io_wq_insert_work() and wq_list_add_after() writes through freed memory. Add the missing io_wq_is_hashed() check so a non-hashed predecessor never inherits a hash_tail[] slot. Cc: stable@vger.kernel.org Fixes: 204361a77f40 ("io-wq: fix hang after cancelling pending hashed work") Signed-off-by: Nicholas Carlini <nicholas@carlini.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-23fdget(), trivial conversionsAl Viro1-21/+8
[ Upstream commit 6348be02eead77bdd1562154ed6b3296ad3b3750 ] fdget() is the first thing done in scope, all matching fdput() are immediately followed by leaving the scope. Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Stable-dep-of: 66052a768d47 ("fanotify: call fanotify_events_supported() before path_permission() and security_path_notify()") Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-05-23io_uring/kbuf: use mem_is_zero()Pavel Begunkov1-10/+4
commit 1724849072854a66861d461b298b04612702d685 upstream. Make use of mem_is_zero() for reserved fields checking. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/11fe27b7a831329bcdb4ea087317ef123ba7c171.1747150490.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-17io_uring/kbuf: support min length left for incremental buffersMartin Michaelis2-1/+14
commit 7deba791ad495ce1d7921683f4f7d1190fa210d1 upstream. Incrementally consumed buffer rings are generally fully consumed, but it's quite possible that the application has a minimum size it needs to meet to avoid truncation. Currently that minimum limit is 1 byte, but this should be a setting that is the hands of the application. For recvmsg multishot, a prime use case for incrementally consumed buffers, the application may get spurious -EFAULT returned at the end of an incrementally consumed buffer, as less space is available than the headers need. Grab a u32 field in struct io_uring_buf_reg, which the application can use to inform the kernel of the minimum size that should be available in an incrementally consumed buffer. If less than that is available, the current buffer is fully processed and the next one will be picked. Cc: stable@vger.kernel.org Fixes: ae98dbf43d75 ("io_uring/kbuf: add support for incremental buffer consumption") Link: https://github.com/axboe/liburing/issues/1433 Signed-off-by: Martin Michaelis <code@mgjm.de> [axboe: write commit message, change io_buffer_list member name] Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-07io_uring/poll: fix multishot recv missing EOF on wakeup raceJens Axboe1-2/+7
[ Upstream commit a68ed2df72131447d131531a08fe4dfcf4fa4653 ] When a socket send and shutdown() happen back-to-back, both fire wake-ups before the receiver's task_work has a chance to run. The first wake gets poll ownership (poll_refs=1), and the second bumps it to 2. When io_poll_check_events() runs, it calls io_poll_issue() which does a recv that reads the data and returns IOU_RETRY. The loop then drains all accumulated refs (atomic_sub_return(2) -> 0) and exits, even though only the first event was consumed. Since the shutdown is a persistent state change, no further wakeups will happen, and the multishot recv can hang forever. Check specifically for HUP in the poll loop, and ensure that another loop is done to check for status if more than a single poll activation is pending. This ensures we don't lose the shutdown event. Backport notes for linux-6.12.y: - The do-while body in 6.12.y already places `v &= IO_POLL_REF_MASK;` just before the while-condition; the upstream patch moves it earlier so that `v != 1` in the HUP check refers to the ref-count only. The backport does the same. - io_poll_issue takes `ts` (struct io_tw_state *) here. CVE: CVE-2026-23473 Cc: stable@vger.kernel.org # 6.12.y Fixes: dbc2564cfe0f ("io_uring: let fast poll support multishot") Reported-by: Francis Brosseau <francis@malagauche.com> Link: https://github.com/axboe/liburing/issues/1549 Signed-off-by: Jens Axboe <axboe@kernel.dk> [backport for linux-6.12.y, verified 2026-05-01] Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-05-07io_uring/poll: ensure EPOLL_ONESHOT is propagated for EPOLL_URING_WAKEJens Axboe1-1/+3
commit 1967f0b1cafdde37aa9e08e6021c14bcc484b7a5 upstream. Commit: aacf2f9f382c ("io_uring: fix req->apoll_events") fixed an issue where poll->events and req->apoll_events weren't synchronized, but then when the commit referenced in Fixes got added, it didn't ensure the same thing. If we mask in EPOLLONESHOT in the regular EPOLL_URING_WAKE path, then ensure it's done for both. Including a link to the original report below, even though it's mostly nonsense. But it includes a reproducer that does show that IORING_CQE_F_MORE is set in the previous CQE, while no more CQEs will be generated for this request. Just ignore anything that pretends this is security related in any way, it's just the typical AI nonsense. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/io-uring/CAM0zi7yQzF3eKncgHo4iVM5yFLAjsiob_ucqyWKs=hyd_GqiMg@mail.gmail.com/ Reported-by: Azizcan Daştan <azizcan.d@mileniumsec.com> Fixes: 4464853277d0 ("io_uring: pass in EPOLL_URING_WAKE for eventfd signaling and wakeups") Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-07io_uring/poll: fix signed comparison in io_poll_get_ownership()Longxuan Yu1-1/+1
commit 326941b22806cbf2df1fbfe902b7908b368cce42 upstream. io_poll_get_ownership() uses a signed comparison to check whether poll_refs has reached the threshold for the slowpath: if (unlikely(atomic_read(&req->poll_refs) >= IO_POLL_REF_BIAS)) atomic_read() returns int (signed). When IO_POLL_CANCEL_FLAG (BIT(31)) is set in poll_refs, the value becomes negative in signed arithmetic, so the >= 128 comparison always evaluates to false and the slowpath is never taken. Fix this by casting the atomic_read() result to unsigned int before the comparison, so that the cancel flag is treated as a large positive value and correctly triggers the slowpath. Fixes: a26a35e9019f ("io_uring: make poll refs more robust") Cc: stable@vger.kernel.org Reported-by: Yifan Wu <yifanwucs@gmail.com> Reported-by: Juefei Pu <tomapufckgml@gmail.com> Co-developed-by: Yuan Tan <yuantan098@gmail.com> Signed-off-by: Yuan Tan <yuantan098@gmail.com> Suggested-by: Xin Liu <bird@lzu.edu.cn> Tested-by: Zhengchuan Liang <zcliangcn@gmail.com> Signed-off-by: Longxuan Yu <ylong030@ucr.edu> Signed-off-by: Ren Wei <n05ec@lzu.edu.cn> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://patch.msgid.link/3a3508b08bcd7f1bc3beff848ae6e1d73d355043.1775965597.git.ylong030@ucr.edu Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-07io_uring/timeout: check unused sqe fieldsPavel Begunkov1-0/+4
commit 484ae637a3e3d909718de7c07afd3bb34b6b8504 upstream. Zero check unused SQE fields addr3 and pad2 for timeout and timeout update requests. They're not needed now, but could be used sometime in the future. Cc: stable@vger.kernel.org Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/net: fix slab-out-of-bounds read in io_bundle_nbufs()Junxi Qian1-0/+4
commit b948f9d5d3057b01188e36664e7c7604d1c8ecb5 upstream. sqe->len is __u32 but gets stored into sr->len which is int. When userspace passes sqe->len values exceeding INT_MAX (e.g. 0xFFFFFFFF), sr->len overflows to a negative value. This negative value propagates through the bundle recv/send path: 1. io_recv(): sel.val = sr->len (ssize_t gets -1) 2. io_recv_buf_select(): arg.max_len = sel->val (size_t gets 0xFFFFFFFFFFFFFFFF) 3. io_ring_buffers_peek(): buf->len is not clamped because max_len is astronomically large 4. iov[].iov_len = 0xFFFFFFFF flows into io_bundle_nbufs() 5. io_bundle_nbufs(): min_t(int, 0xFFFFFFFF, ret) yields -1, causing ret to increase instead of decrease, creating an infinite loop that reads past the allocated iov[] array This results in a slab-out-of-bounds read in io_bundle_nbufs() from the kmalloc-64 slab, as nbufs increments past the allocated iovec entries. BUG: KASAN: slab-out-of-bounds in io_bundle_nbufs+0x128/0x160 Read of size 8 at addr ffff888100ae05c8 by task exp/145 Call Trace: io_bundle_nbufs+0x128/0x160 io_recv_finish+0x117/0xe20 io_recv+0x2db/0x1160 Fix this by rejecting negative sr->len values early in both io_sendmsg_prep() and io_recvmsg_prep(). Since sqe->len is __u32, any value > INT_MAX indicates overflow and is not a valid length. Fixes: a05d1f625c7a ("io_uring/net: support bundles for send") Cc: stable@vger.kernel.org Signed-off-by: Junxi Qian <qjx1298677004@gmail.com> Link: https://patch.msgid.link/20260329153909.279046-1-qjx1298677004@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/kbuf: propagate BUF_MORE through early buffer commit pathJens Axboe1-1/+4
Commit 418eab7a6f3c002d8e64d6e95ec27118017019af upstream. When io_should_commit() returns true (eg for non-pollable files), buffer commit happens at buffer selection time and sel->buf_list is set to NULL. When __io_put_kbufs() generates CQE flags at completion time, it calls __io_put_kbuf_ring() which finds a NULL buffer_list and hence cannot determine whether the buffer was consumed or not. This means that IORING_CQE_F_BUF_MORE is never set for non-pollable input with incrementally consumed buffers. Likewise for io_buffers_select(), which always commits upfront and discards the return value of io_kbuf_commit(). Add REQ_F_BUF_MORE to store the result of io_kbuf_commit() during early commit. Then __io_put_kbuf_ring() can check this flag and set IORING_F_BUF_MORE accordingy. Reported-by: Martin Michaelis <code@mgjm.de> Cc: stable@vger.kernel.org Fixes: ae98dbf43d75 ("io_uring/kbuf: add support for incremental buffer consumption") Link: https://github.com/axboe/liburing/issues/1553 Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/kbuf: fix missing BUF_MORE for incremental buffers at EOFJens Axboe1-0/+4
Commit 3ecd3e03144b38a21a3b70254f1b9d2e16629b09 upstream. For a zero length transfer, io_kbuf_inc_commit() is called with !len. Since we never enter the while loop to consume the buffers, io_kbuf_inc_commit() ends up returning true, consuming the buffer. But if no data was consumed, by definition it cannot have consumed the buffer. Return false for that case. Reported-by: Martin Michaelis <code@mgjm.de> Cc: stable@vger.kernel.org Fixes: ae98dbf43d75 ("io_uring/kbuf: add support for incremental buffer consumption") Link: https://github.com/axboe/liburing/issues/1553 Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/kbuf: use WRITE_ONCE() for userspace-shared buffer ring fieldsJoanne Koong1-4/+4
Commit a4c694bfc2455e82b7caf6045ca893d123e0ed11 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/kbuf: use READ_ONCE() for userspace-mapped memoryCaleb Sander Mateos1-5/+5
Commit 78385c7299f7514697d196b3233a91bd5e485591 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/kbuf: always use READ_ONCE() to read ring provided buffer lengthsJens Axboe1-7/+13
Commit 98b6fa62c84f2e129161e976a5b9b3cb4ccd117b upstream. Since the buffers are mapped from userspace, it is prudent to use READ_ONCE() to read the value into a local variable, and use that for any other actions taken. Having a stable read of the buffer length avoids worrying about it changing after checking, or being read multiple times. Similarly, the buffer may well change in between it being picked and being committed. Ensure the looping for incremental ring buffer commit stops if it hits a zero sized buffer, as no further progress can be made at that point. Fixes: ae98dbf43d75 ("io_uring/kbuf: add support for incremental buffer consumption") Link: https://lore.kernel.org/io-uring/tencent_000C02641F6250C856D0C26228DE29A3D30A@qq.com/ Reported-by: Qingyue Zhang <chunzhennn@qq.com> Reported-by: Suoxing Zhang <aftern00n@qq.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/kbuf: enable bundles for incrementally consumed buffersJens Axboe1-30/+26
Commit cf9536e550dd243a1681fdbf804221527da20a80 upstream. The original support for incrementally consumed buffers didn't allow it to be used with bundles, with the assumption being that incremental buffers are generally larger, and hence there's less of a nedd to support it. But that assumption may not be correct - it's perfectly viable to use smaller buffers with incremental consumption, and there may be valid reasons for an application or framework to do so. As there's really no need to explicitly disable bundles with incrementally consumed buffers, allow it. This actually makes the peek side cheaper and simpler, with the completion side basically the same, just needing to iterate for the consumed length. Reported-by: Norman Maurer <norman_maurer@apple.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/rw: check for NULL io_br_sel when putting a bufferJens Axboe1-2/+5
Commit 18d6b1743eafeb3fb1e0ea5a2b7fd0a773d525a8 upstream. Both the read and write side use kiocb_done() to finish a request, and kiocb_done() will call io_put_kbuf() in case a provided buffer was used for the request. Provided buffers are not supported for writes, hence NULL is being passed in. This normally works fine, as io_put_kbuf() won't actually use the value unless REQ_F_BUFFER_RING or REQ_F_BUFFER_SELECTED is set in the request flags. But depending on compiler (or whether or not CONFIG_CC_OPTIMIZE_FOR_SIZE is set), that may be done even though the value is never used. This will then cause a NULL pointer dereference. Make it a bit more obvious and check for a NULL io_br_sel, and don't even bother calling io_put_kbuf() for that case. Fixes: 5fda51255439 ("io_uring/kbuf: switch to storing struct io_buffer_list locally") Reported-by: David Howells <dhowells@redhat.com> Tested-by: David Howells <dhowells@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/net: correct type for min_not_zero() castJens Axboe1-1/+1
Commit 37500634d0a8f931e15879760fb70f9b6f5d5370 upstream. The kernel test robot reports that after a recent change, the signedness of a min_not_zero() compare is now incorrect. Fix that up and cast to the right type. Fixes: 429884ff35f7 ("io_uring/kbuf: use struct io_br_sel for multiple buffers picking") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202509020426.WJtrdwOU-lkp@intel.com/ Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring: remove async/poll related provided buffer recyclesJens Axboe2-6/+0
Commit e973837b54024f070b2b48c7ee9725548548257a upstream. These aren't necessary anymore, get rid of them. Link: https://lore.kernel.org/r/20250821020750.598432-13-axboe@kernel.dk Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/kbuf: switch to storing struct io_buffer_list locallyJens Axboe6-68/+60
Commit 5fda51255439addd1c9059098e30847a375a1008 upstream. Currently the buffer list is stored in struct io_kiocb. The buffer list can be of two types: 1) Classic/legacy buffer list. These don't need to get referenced after a buffer pick, and hence storing them in struct io_kiocb is perfectly fine. 2) Ring provided buffer lists. These DO need to be referenced after the initial buffer pick, as they need to get consumed later on. This can be either just incrementing the head of the ring, or it can be consuming parts of a buffer if incremental buffer consumptions has been configured. For case 2, io_uring needs to be careful not to access the buffer list after the initial pick-and-execute context. The core does recycling of these, but it's easy to make a mistake, because it's stored in the io_kiocb which does persist across multiple execution contexts. Either because it's a multishot request, or simply because it needed some kind of async trigger (eg poll) for retry purposes. Add a struct io_buffer_list to struct io_br_sel, which is always on stack for the various users of it. This prevents the buffer list from leaking outside of that execution context, and additionally it enables kbuf to not even pass back the struct io_buffer_list if the given context isn't appropriately locked already. This doesn't fix any bugs, it's simply a defensive measure to prevent any issues with reuse of a buffer list. Link: https://lore.kernel.org/r/20250821020750.598432-12-axboe@kernel.dk Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/net: use struct io_br_sel->val as the send finish valueJens Axboe1-10/+12
Commit 461382a51fb83a9c4b7c50e1f10d3ca94edff25e upstream. Currently a pointer is passed in to the 'ret' in the send mshot handler, but since we already have a value field in io_br_sel, just use that. This is also in preparation for needing to pass in struct io_br_sel to io_send_finish() anyway. Link: https://lore.kernel.org/r/20250821020750.598432-11-axboe@kernel.dk Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/net: use struct io_br_sel->val as the recv finish valueJens Axboe1-14/+17
Commit 58d815091890e83aa2f83a9cce1fdfe3af02c7b4 upstream. Currently a pointer is passed in to the 'ret' in the receive handlers, but since we already have a value field in io_br_sel, just use that. This is also in preparation for needing to pass in struct io_br_sel to io_recv_finish() anyway. Link: https://lore.kernel.org/r/20250821020750.598432-10-axboe@kernel.dk Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/kbuf: use struct io_br_sel for multiple buffers pickingJens Axboe3-18/+23
Commit 429884ff35f75a8ac3e8f822f483e220e3ea6394 upstream. The networking side uses bundles, which is picking multiple buffers at the same time. Pass in struct io_br_sel to those helpers. Link: https://lore.kernel.org/r/20250821020750.598432-9-axboe@kernel.dk Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/kbuf: introduce struct io_br_selJens Axboe4-37/+57
Commit ab6559bdbb08f6bee606435cd014fc5ba0f7b750 upstream. Rather than return addresses directly from buffer selection, add a struct around it. No functional changes in this patch, it's in preparation for storing more buffer related information locally, rather than in struct io_kiocb. Link: https://lore.kernel.org/r/20250821020750.598432-7-axboe@kernel.dk Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/kbuf: pass in struct io_buffer_list to commit/recycle helpersJens Axboe6-45/+46
Commit 1b5add75d7c894c62506c9b55f1d9eaadae50ef1 upstream. Rather than have this implied being in the io_kiocb, pass it in directly so it's immediately obvious where these users of ->buf_list are coming from. Link: https://lore.kernel.org/r/20250821020750.598432-6-axboe@kernel.dk Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/net: clarify io_recv_buf_select() return valueJens Axboe1-1/+1
Commit b22743f29b7d3dc68c68f9bd39a1b2600ec6434e upstream. It returns 0 on success, less than zero on error. Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/net: don't use io_net_kbuf_recyle() for non-provided casesJens Axboe1-3/+3
Commit 15ba5e51e689ceb1c2e921c5180a70c88cfdc8e9 upstream. A previous commit used io_net_kbuf_recyle() for any network helper that did IO and needed partial retry. However, that's only needed if the opcode does buffer selection, which isnt support for sendzc, sendmsg_zc, or sendmsg. Just remove them - they don't do any harm, but it is a bit confusing when reading the code. Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/kbuf: drop 'issue_flags' from io_put_kbuf(s)() argumentsJens Axboe4-17/+14
Commit 5e73b402cbbea51bcab90fc5ee6c6d06af76ae1b upstream. Picking multiple buffers always requires the ring lock to be held across the operation, so there's no need to pass in the issue_flags to io_put_kbufs(). On the single buffer side, if the initial picking of a ring buffer was unlocked, then it will have been committed already. For legacy buffers, no locking is required, as they will simply be freed. Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/kbuf: uninline __io_put_kbufsPavel Begunkov2-63/+70
Commit 5d3e51240d89678b87b5dc6987ea572048a0f0eb upstream. __io_put_kbufs() and other helper functions are too large to be inlined, compilers would normally refuse to do so. Uninline it and move together with io_kbuf_commit into kbuf.c. io_kbuf_commitSigned-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/3dade7f55ad590e811aff83b1ec55c9c04e17b2b.1738724373.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/kbuf: introduce io_kbuf_drop_legacy()Pavel Begunkov3-25/+14
Commit 54e00d9a612ab93f37f612a5ccd7c0c4f8a31cea upstream. io_kbuf_drop() is only used for legacy provided buffers, and so __io_put_kbuf_list() is never called for REQ_F_BUFFER_RING. Remove the dead branch out of __io_put_kbuf_list(), rename it into io_kbuf_drop_legacy() and use it directly instead of io_kbuf_drop(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/c8cc73e2272f09a86ecbdad9ebdd8304f8e583c0.1738724373.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/kbuf: open code __io_put_kbuf()Pavel Begunkov2-8/+1
Commit e150e70fce425e1cdfc227974893cad9fb90a0d3 upstream. __io_put_kbuf() is a trivial wrapper, open code it into __io_put_kbufs(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/9dc17380272b48d56c95992c6f9eaacd5546e1d3.1738724373.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/kbuf: remove legacy kbuf cachingPavel Begunkov3-56/+9
Commit 13ee854e7c04236a47a5beaacdcf51eb0bc7a8fa upstream. Remove all struct io_buffer caches. It makes it a fair bit simpler. Apart from from killing a bunch of lines and juggling between lists, __io_put_kbuf_list() doesn't need ->completion_lock locking now. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/18287217466ee2576ea0b1e72daccf7b22c7e856.1738724373.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/kbuf: simplify __io_put_kbufPavel Begunkov3-31/+8
Commit dc39fb1093ea33019f192c93b77b863282e10162 upstream. As a preparation step remove an optimisation from __io_put_kbuf() trying to use the locked cache. With that __io_put_kbuf_list() is only used with ->io_buffers_comp, and we remove the explicit list argument. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/1b7f1394ec4afc7f96b35a61f5992e27c49fd067.1738724373.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/kbuf: remove legacy kbuf kmem cachePavel Begunkov3-8/+3
Commit 9afe6847cff78e7f3aa8f4c920265cf298033251 upstream. Remove the kmem cache used by legacy provided buffers. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/8195c207d8524d94e972c0c82de99282289f7f5c.1738724373.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-11io_uring/kbuf: remove legacy kbuf bulk allocationPavel Begunkov1-25/+5
Commit 7919292a961421bfdb22f83c16657684c96076b3 upstream. Legacy provided buffers are slow and discouraged in favour of the ring variant. Remove the bulk allocation to keep it simpler as we don't care about performance. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/a064d70370e590efed8076e9501ae4cfc20fe0ca.1738724373.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-25io_uring/kbuf: propagate BUF_MORE through early buffer commit pathJens Axboe2-3/+7
Commit 418eab7a6f3c002d8e64d6e95ec27118017019af upstream. When io_should_commit() returns true (eg for non-pollable files), buffer commit happens at buffer selection time and sel->buf_list is set to NULL. When __io_put_kbufs() generates CQE flags at completion time, it calls __io_put_kbuf_ring() which finds a NULL buffer_list and hence cannot determine whether the buffer was consumed or not. This means that IORING_CQE_F_BUF_MORE is never set for non-pollable input with incrementally consumed buffers. Likewise for io_buffers_select(), which always commits upfront and discards the return value of io_kbuf_commit(). Add REQ_F_BUF_MORE to store the result of io_kbuf_commit() during early commit. Then __io_put_kbuf_ring() can check this flag and set IORING_F_BUF_MORE accordingy. Reported-by: Martin Michaelis <code@mgjm.de> Cc: stable@vger.kernel.org Fixes: ae98dbf43d75 ("io_uring/kbuf: add support for incremental buffer consumption") Link: https://github.com/axboe/liburing/issues/1553 Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-25io_uring/kbuf: check if target buffer list is still legacy on recycleJens Axboe1-2/+10
Commit c2c185be5c85d37215397c8e8781abf0a69bec1f upstream. There's a gap between when the buffer was grabbed and when it potentially gets recycled, where if the list is empty, someone could've upgraded it to a ring provided type. This can happen if the request is forced via io-wq. The legacy recycling is missing checking if the buffer_list still exists, and if it's of the correct type. Add those checks. Cc: stable@vger.kernel.org Fixes: c7fb19428d67 ("io_uring: add support for ring mapped supplied buffers") Reported-by: Keenan Dong <keenanat2000@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-25io_uring/uring_cmd: fix too strict requirement on ioctlAsbjørn Sloth Tønnesen1-3/+6
[ Upstream commit 600b665b903733bd60334e86031b157cc823ee55 ] Attempting SOCKET_URING_OP_SETSOCKOPT on an AF_NETLINK socket resulted in an -EOPNOTSUPP, as AF_NETLINK doesn't have an ioctl in its struct proto, but only in struct proto_ops. Prior to the blamed commit, io_uring_cmd_sock() only had two cmd_op operations, both requiring ioctl, thus the check was warranted. Since then, 4 new cmd_op operations have been added, none of which depend on ioctl. This patch moves the ioctl check, so it only applies to the original operations. AFAICT, the ioctl requirement was unintentional, and it wasn't visible in the blamed patch within 3 lines of context. Cc: stable@vger.kernel.org Fixes: a5d2f99aff6b ("io_uring/cmd: Introduce SOCKET_URING_OP_GETSOCKOPT") Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net> Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> [Asbjørn: function moved in commit 91db6edc573b; updated subject prefix] Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-04io_uring/filetable: clamp alloc_hint to the configured alloc rangeJens Axboe1-0/+4
[ Upstream commit a6bded921ed35f21b3f6bd8e629bf488499ca442 ] Explicit fixed file install/remove operations on slots outside the configured alloc range can corrupt alloc_hint via io_file_bitmap_set() and io_file_bitmap_clear(), which unconditionally update alloc_hint to the bit position. This causes subsequent auto-allocations to fall outside the configured range. For example, if the alloc range is [10, 20) and a file is removed at slot 2, alloc_hint gets set to 2. The next auto-alloc then starts searching from slot 2, potentially returning a slot below the range. Fix this by clamping alloc_hint to [file_alloc_start, file_alloc_end) at the top of io_file_bitmap_get() before starting the search. Cc: stable@vger.kernel.org Fixes: 6e73dffbb93c ("io_uring: let to set a range for file slot allocation") Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04io_uring/net: don't continue send bundle if poll was required for retryJens Axboe1-1/+5
[ Upstream commit 806ae939c41e5da1d94a1e2b31f5702e96b6c3e3 ] If a send bundle has picked a bunch of buffers, then it needs to send all of those to be complete. This may require poll arming, if the send buffer ends up being full. Once a send bundle has been poll armed, no further bundles should be attempted. This allows a current bundle to complete even though it needs to go through polling to do so, but it will not allow another bundle to be started once that has happened. Ideally we would abort a bundle if it was only partially sent, but as some parts of it already went out on the wire, this obviously isn't feasible. Not continuing more bundle attempts post encountering a full socket buffer is the second best thing. Cc: stable@vger.kernel.org Fixes: a05d1f625c7a ("io_uring/net: support bundles for send") Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>