Backport from ml:
commit a8a86d78d673b1c99fe9b0064739fde9e9774184
Author: Tahsin Erdogan <[email protected]>
Date: Thu Jan 12 12:04:04 2017 -0800
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 <[email protected]>
Signed-off-by: Miklos Szeredi <[email protected]>
Signed-off-by: Maxim Patlasov <[email protected]>
---
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 d8360e6..69353e4 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -2078,7 +2078,6 @@ 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);
@@ -2156,6 +2155,8 @@ 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);
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