| commit | caeb4b0a11b3393e43f7fa8e0a5a18462acc66bd | [log] [tgz] |
|---|---|---|
| author | Kent Overstreet <kent.overstreet@linux.dev> | Sun Mar 31 17:52:12 2024 -0400 |
| committer | Christian Brauner <brauner@kernel.org> | Fri Apr 05 11:20:28 2024 +0200 |
| tree | 4da15d8b35f3fc59a96524eb7aa55852f87fe98f | |
| parent | 22650a99821dda3d05f1c334ea90330b4982de56 [diff] |
aio: Fix null ptr deref in aio_complete() wakeup
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=vr=FEkyRrtqw@mail.gmail.com/
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Link: https://lore.kernel.org/stable/20240331215212.522544-1-kent.overstreet%40linux.dev
Link: https://lore.kernel.org/r/20240331215212.522544-1-kent.overstreet@linux.dev
Signed-off-by: Christian Brauner <brauner@kernel.org>
diff --git a/fs/aio.c b/fs/aio.c index 9cdaa2f..0f4f531 100644 --- a/fs/aio.c +++ b/fs/aio.c
@@ -1202,8 +1202,8 @@ 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); }