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| author | Tahsin Erdogan <tahsin@google.com> | 2017-01-12 12:04:04 -0800 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2017-01-13 12:03:47 +0100 |
| commit | a8a86d78d673b1c99fe9b0064739fde9e9774184 (patch) | |
| tree | 12aaf53834805de16bf1cb6af09aa107695babde | |
| parent | a121103c922847ba5010819a3f250f1f7fc84ab8 (diff) | |
| download | linux-a8a86d78d673b1c99fe9b0064739fde9e9774184.tar.gz linux-a8a86d78d673b1c99fe9b0064739fde9e9774184.tar.bz2 linux-a8a86d78d673b1c99fe9b0064739fde9e9774184.zip | |
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 <tahsin@google.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: <stable@vger.kernel.org> # 4.2+
| -rw-r--r-- | fs/fuse/dev.c | 3 |
1 files changed, 2 insertions, 1 deletions
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); |