5.10-stable patches

added patches:
	io_uring-io-wq-check-io_wq_bit_exit-inside-work-run-loop.patch

diff --git a/queue-5.10/io_uring-io-wq-check-io_wq_bit_exit-inside-work-run-loop.patch b/queue-5.10/io_uring-io-wq-check-io_wq_bit_exit-inside-work-run-loop.patch
new file mode 100644 (file)
index 0000000..6f0a5c7
--- /dev/null
+++ b/queue-5.10/io_uring-io-wq-check-io_wq_bit_exit-inside-work-run-loop.patch
@@ -0,0 +1,91 @@
+From 10dc959398175736e495f71c771f8641e1ca1907 Mon Sep 17 00:00:00 2001
+From: Jens Axboe <axboe@kernel.dk>
+Date: Tue, 20 Jan 2026 07:42:50 -0700
+Subject: io_uring/io-wq: check IO_WQ_BIT_EXIT inside work run loop
+
+From: Jens Axboe <axboe@kernel.dk>
+
+commit 10dc959398175736e495f71c771f8641e1ca1907 upstream.
+
+Currently this is checked before running the pending work. Normally this
+is quite fine, as work items either end up blocking (which will create a
+new worker for other items), or they complete fairly quickly. But syzbot
+reports an issue where io-wq takes seemingly forever to exit, and with a
+bit of debugging, this turns out to be because it queues a bunch of big
+(2GB - 4096b) reads with a /dev/msr* file. Since this file type doesn't
+support ->read_iter(), loop_rw_iter() ends up handling them. Each read
+returns 16MB of data read, which takes 20 (!!) seconds. With a bunch of
+these pending, processing the whole chain can take a long time. Easily
+longer than the syzbot uninterruptible sleep timeout of 140 seconds.
+This then triggers a complaint off the io-wq exit path:
+
+INFO: task syz.4.135:6326 blocked for more than 143 seconds.
+      Not tainted syzkaller #0
+      Blocked by coredump.
+"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
+task:syz.4.135       state:D stack:26824 pid:6326  tgid:6324  ppid:5957   task_flags:0x400548 flags:0x00080000
+Call Trace:
+ <TASK>
+ context_switch kernel/sched/core.c:5256 [inline]
+ __schedule+0x1139/0x6150 kernel/sched/core.c:6863
+ __schedule_loop kernel/sched/core.c:6945 [inline]
+ schedule+0xe7/0x3a0 kernel/sched/core.c:6960
+ schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
+ do_wait_for_common kernel/sched/completion.c:100 [inline]
+ __wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:121
+ io_wq_exit_workers io_uring/io-wq.c:1328 [inline]
+ io_wq_put_and_exit+0x271/0x8a0 io_uring/io-wq.c:1356
+ io_uring_clean_tctx+0x10d/0x190 io_uring/tctx.c:203
+ io_uring_cancel_generic+0x69c/0x9a0 io_uring/cancel.c:651
+ io_uring_files_cancel include/linux/io_uring.h:19 [inline]
+ do_exit+0x2ce/0x2bd0 kernel/exit.c:911
+ do_group_exit+0xd3/0x2a0 kernel/exit.c:1112
+ get_signal+0x2671/0x26d0 kernel/signal.c:3034
+ arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337
+ __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
+ exit_to_user_mode_loop+0x8c/0x540 kernel/entry/common.c:75
+ __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
+ syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
+ syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
+ syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
+ do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
+ entry_SYSCALL_64_after_hwframe+0x77/0x7f
+RIP: 0033:0x7fa02738f749
+RSP: 002b:00007fa0281ae0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
+RAX: fffffffffffffe00 RBX: 00007fa0275e6098 RCX: 00007fa02738f749
+RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fa0275e6098
+RBP: 00007fa0275e6090 R08: 0000000000000000 R09: 0000000000000000
+R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
+R13: 00007fa0275e6128 R14: 00007fff14e4fcb0 R15: 00007fff14e4fd98
+
+There's really nothing wrong here, outside of processing these reads
+will take a LONG time. However, we can speed up the exit by checking the
+IO_WQ_BIT_EXIT inside the io_worker_handle_work() loop, as syzbot will
+exit the ring after queueing up all of these reads. Then once the first
+item is processed, io-wq will simply cancel the rest. That should avoid
+syzbot running into this complaint again.
+
+Cc: stable@vger.kernel.org
+Link: https://lore.kernel.org/all/68a2decc.050a0220.e29e5.0099.GAE@google.com/
+Reported-by: syzbot+4eb282331cab6d5b6588@syzkaller.appspotmail.com
+Signed-off-by: Jens Axboe <axboe@kernel.dk>
+[ Minor conflict resolved. ]
+Signed-off-by: Jianqiang kang <jianqkang@sina.cn>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ io_uring/io-wq.c |    2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/io_uring/io-wq.c
++++ b/io_uring/io-wq.c
+@@ -554,9 +554,9 @@ static void io_worker_handle_work(struct
+       struct io_wqe_acct *acct = io_wqe_get_acct(worker);
+       struct io_wqe *wqe = worker->wqe;
+       struct io_wq *wq = wqe->wq;
+-      bool do_kill = test_bit(IO_WQ_BIT_EXIT, &wq->state);
+ 
+       do {
++              bool do_kill = test_bit(IO_WQ_BIT_EXIT, &wq->state);
+               struct io_wq_work *work;
+ get_next:
+               /*

diff --git a/queue-5.10/series b/queue-5.10/series
index ef188512acf0c6fed915913a92acf7e45e7e5bd8..4517f448f83a498206d8912bc3cc4e50cb00a970 100644 (file)
--- a/queue-5.10/series
+++ b/queue-5.10/series
@@ -134,3 +134,4 @@ iio-gyro-mpu3050-i2c-fix-pm_runtime-error-handling.patch
 iio-imu-inv_icm42600-fix-odr-switch-to-the-same-value.patch
 bpf-forget-ranges-when-refining-tnum-after-jset.patch
 l2tp-do-not-use-sock_hold-in-pppol2tp_session_get_sock.patch
+io_uring-io-wq-check-io_wq_bit_exit-inside-work-run-loop.patch