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| author | Pavel Begunkov <asml.silence@gmail.com> | 2025-03-22 11:47:27 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-03-28 22:04:58 +0100 |
| commit | 9752dd3bf4bf2aca1b271a973f9416b6135f6146 (patch) | |
| tree | f1dc897c76d18e38b5df197e744756667d382fb4 | |
| parent | f6a6721802ac2f12f4c1bbe839a4c229b61866f2 (diff) | |
| download | linux-9752dd3bf4bf2aca1b271a973f9416b6135f6146.tar.gz linux-9752dd3bf4bf2aca1b271a973f9416b6135f6146.tar.bz2 linux-9752dd3bf4bf2aca1b271a973f9416b6135f6146.zip | |
io_uring/net: fix sendzc double notif flush
commit 67c007d6c12da3e456c005083696c20d4498ae72 upstream.
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 5823 at lib/refcount.c:28 refcount_warn_saturate+0x15a/0x1d0 lib/refcount.c:28
RIP: 0010:refcount_warn_saturate+0x15a/0x1d0 lib/refcount.c:28
Call Trace:
<TASK>
io_notif_flush io_uring/notif.h:40 [inline]
io_send_zc_cleanup+0x121/0x170 io_uring/net.c:1222
io_clean_op+0x58c/0x9a0 io_uring/io_uring.c:406
io_free_batch_list io_uring/io_uring.c:1429 [inline]
__io_submit_flush_completions+0xc16/0xd20 io_uring/io_uring.c:1470
io_submit_flush_completions io_uring/io_uring.h:159 [inline]
Before the blamed commit, sendzc relied on io_req_msg_cleanup() to clear
REQ_F_NEED_CLEANUP, so after the following snippet the request will
never hit the core io_uring cleanup path.
io_notif_flush();
io_req_msg_cleanup();
The easiest fix is to null the notification. io_send_zc_cleanup() can
still be called after, but it's tolerated.
Reported-by: syzbot+cf285a028ffba71b2ef5@syzkaller.appspotmail.com
Tested-by: syzbot+cf285a028ffba71b2ef5@syzkaller.appspotmail.com
Fixes: cc34d8330e036 ("io_uring/net: don't clear REQ_F_NEED_CLEANUP unconditionally")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e1306007458b8891c88c4f20c966a17595f766b0.1742643795.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | io_uring/net.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/io_uring/net.c b/io_uring/net.c index 28688b6a3a50..f4c626029ba7 100644 --- a/io_uring/net.c +++ b/io_uring/net.c @@ -1439,6 +1439,7 @@ int io_send_zc(struct io_kiocb *req, unsigned int issue_flags) */ if (!(issue_flags & IO_URING_F_UNLOCKED)) { io_notif_flush(zc->notif); + zc->notif = NULL; io_req_msg_cleanup(req, 0); } io_req_set_res(req, ret, IORING_CQE_F_MORE); @@ -1499,6 +1500,7 @@ int io_sendmsg_zc(struct io_kiocb *req, unsigned int issue_flags) */ if (!(issue_flags & IO_URING_F_UNLOCKED)) { io_notif_flush(sr->notif); + sr->notif = NULL; io_req_msg_cleanup(req, 0); } io_req_set_res(req, ret, IORING_CQE_F_MORE); |