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: linux-stable@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/linux-fsdevel/CAHTA-ubfwwB51A5Wg5M6H_rPEQK9pNf8FkAGH=vr=FEkyRrtqw@xxxxxxxxxxxxxx/ Signed-off-by: Kent Overstreet <kent.overstreet@xxxxxxxxx> --- fs/aio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/aio.c b/fs/aio.c index 9cdaa2faa536..0f4f531c9780 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -1202,8 +1202,8 @@ static void aio_complete(struct aio_kiocb *iocb) 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); } -- 2.43.0
