6.8-stable review patch. If anyone has any objections, please let me know.
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From: Kent Overstreet kent.overstreet@linux.dev
commit caeb4b0a11b3393e43f7fa8e0a5a18462acc66bd upstream.
list_del_init_careful() needs to be the last access to the wait queue entry - it effectively unlocks access.
Previously, finish_wait() would see the empty list head and skip taking the lock, and then we'd return - but the completion path would still attempt to do the wakeup after the task_struct pointer had been overwritten.
Fixes: 71eb6b6b0ba9 ("fs/aio: obey min_nr when doing wakeups") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/linux-fsdevel/CAHTA-ubfwwB51A5Wg5M6H_rPEQK9pNf8FkAGH... Signed-off-by: Kent Overstreet kent.overstreet@linux.dev Link: https://lore.kernel.org/stable/20240331215212.522544-1-kent.overstreet%40lin... Link: https://lore.kernel.org/r/20240331215212.522544-1-kent.overstreet@linux.dev Signed-off-by: Christian Brauner brauner@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/aio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/aio.c +++ b/fs/aio.c @@ -1202,8 +1202,8 @@ static void aio_complete(struct aio_kioc spin_lock_irqsave(&ctx->wait.lock, flags); list_for_each_entry_safe(curr, next, &ctx->wait.head, w.entry) if (avail >= curr->min_nr) { - list_del_init_careful(&curr->w.entry); wake_up_process(curr->w.private); + list_del_init_careful(&curr->w.entry); } spin_unlock_irqrestore(&ctx->wait.lock, flags); }