The patch below does not apply to the 6.8-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.8.y git checkout FETCH_HEAD git cherry-pick -x 978e5c19dfefc271e5550efba92fcef0d3f62864 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024041501-repulsion-purging-1a06@gregkh' --subject-prefix 'PATCH 6.8.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 978e5c19dfefc271e5550efba92fcef0d3f62864 Mon Sep 17 00:00:00 2001 From: Alexey Izbyshev izbyshev@ispras.ru Date: Fri, 5 Apr 2024 15:55:51 +0300 Subject: [PATCH] io_uring: Fix io_cqring_wait() not restoring sigmask on get_timespec64() failure

This bug was introduced in commit 950e79dd7313 ("io_uring: minor io_cqring_wait() optimization"), which was made in preparation for adc8682ec690 ("io_uring: Add support for napi_busy_poll"). The latter got reverted in cb3182167325 ("Revert "io_uring: Add support for napi_busy_poll""), so simply undo the former as well.

Cc: stable@vger.kernel.org Fixes: 950e79dd7313 ("io_uring: minor io_cqring_wait() optimization") Signed-off-by: Alexey Izbyshev izbyshev@ispras.ru Link: https://lore.kernel.org/r/20240405125551.237142-1-izbyshev@ispras.ru Signed-off-by: Jens Axboe axboe@kernel.dk

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 4521c2b66b98..c170a2b8d2cf 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -2602,19 +2602,6 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, if (__io_cqring_events_user(ctx) >= min_events) return 0;

- if (sig) { -#ifdef CONFIG_COMPAT - if (in_compat_syscall()) - ret = set_compat_user_sigmask((const compat_sigset_t __user *)sig, - sigsz); - else -#endif - ret = set_user_sigmask(sig, sigsz); - - if (ret) - return ret; - } - init_waitqueue_func_entry(&iowq.wq, io_wake_function); iowq.wq.private = current; INIT_LIST_HEAD(&iowq.wq.entry); @@ -2633,6 +2620,19 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, io_napi_adjust_timeout(ctx, &iowq, &ts); }

+ if (sig) { +#ifdef CONFIG_COMPAT + if (in_compat_syscall()) + ret = set_compat_user_sigmask((const compat_sigset_t __user *)sig, + sigsz); + else +#endif + ret = set_user_sigmask(sig, sigsz); + + if (ret) + return ret; + } + io_napi_busy_loop(ctx, &iowq);

trace_io_uring_cqring_wait(ctx, min_events);