From 2b319d1f6f92a4ced9897678113d176ee16ae85d Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Mon, 21 Oct 2019 09:11:40 +0200 Subject: fuse: don't dereference req->args on finished request Move the check for async request after check for the request being already finished and done with. Reported-by: syzbot+ae0bb7aae3de6b4594e2@syzkaller.appspotmail.com Fixes: d49937749fef ("fuse: stop copying args to fuse_req") Signed-off-by: Miklos Szeredi --- fs/fuse/dev.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index dadd617d826c..ed1abc9e33cf 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -276,10 +276,12 @@ static void flush_bg_queue(struct fuse_conn *fc) void fuse_request_end(struct fuse_conn *fc, struct fuse_req *req) { struct fuse_iqueue *fiq = &fc->iq; - bool async = req->args->end; + bool async; if (test_and_set_bit(FR_FINISHED, &req->flags)) goto put_request; + + async = req->args->end; /* * test_and_set_bit() implies smp_mb() between bit * changing and below intr_entry check. Pairs with -- cgit v1.2.3-59-g8ed1b