From a8a86d78d673b1c99fe9b0064739fde9e9774184 Mon Sep 17 00:00:00 2001 From: Tahsin Erdogan Date: Thu, 12 Jan 2017 12:04:04 -0800 Subject: [PATCH] fuse: clear FR_PENDING flag when moving requests out of pending queue fuse_abort_conn() moves requests from pending list to a temporary list before canceling them. This operation races with request_wait_answer() which also tries to remove the request after it gets a fatal signal. It checks FR_PENDING flag to determine whether the request is still in the pending list. Make fuse_abort_conn() clear FR_PENDING flag so that request_wait_answer() does not remove the request from temporary list. This bug causes an Oops when trying to delete an already deleted list entry in end_requests(). Fixes: ee314a870e40 ("fuse: abort: no fc->lock needed for request ending") Signed-off-by: Tahsin Erdogan Signed-off-by: Miklos Szeredi Cc: # 4.2+ --- fs/fuse/dev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index 70ea57c7b6bb..4e06a27ed7f8 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -2025,7 +2025,6 @@ static void end_requests(struct fuse_conn *fc, struct list_head *head) struct fuse_req *req; req = list_entry(head->next, struct fuse_req, list); req->out.h.error = -ECONNABORTED; - clear_bit(FR_PENDING, &req->flags); clear_bit(FR_SENT, &req->flags); list_del_init(&req->list); request_end(fc, req); @@ -2103,6 +2102,8 @@ void fuse_abort_conn(struct fuse_conn *fc) spin_lock(&fiq->waitq.lock); fiq->connected = 0; list_splice_init(&fiq->pending, &to_end2); + list_for_each_entry(req, &to_end2, list) + clear_bit(FR_PENDING, &req->flags); while (forget_pending(fiq)) kfree(dequeue_forget(fiq, 1, NULL)); wake_up_all_locked(&fiq->waitq);