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author | Miklos Szeredi <mszeredi@redhat.com> | 2021-06-22 09:15:35 +0200 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-20 16:15:42 +0200 |
commit | 1c37784a00edfb88be67b24f7e776cda9eb803fd (patch) | |
tree | 0ec581ee3530f81f9fea27ee27a849922d52f94a /fs | |
parent | 77c94b2a1deea733e2796a2da7b637c1afd0cdb8 (diff) | |
download | linux-stable-1c37784a00edfb88be67b24f7e776cda9eb803fd.tar.gz linux-stable-1c37784a00edfb88be67b24f7e776cda9eb803fd.tar.bz2 linux-stable-1c37784a00edfb88be67b24f7e776cda9eb803fd.zip |
fuse: check connected before queueing on fpq->io
commit 80ef08670d4c28a06a3de954bd350368780bcfef upstream.
A request could end up on the fpq->io list after fuse_abort_conn() has
reset fpq->connected and aborted requests on that list:
Thread-1 Thread-2
======== ========
->fuse_simple_request() ->shutdown
->__fuse_request_send()
->queue_request() ->fuse_abort_conn()
->fuse_dev_do_read() ->acquire(fpq->lock)
->wait_for(fpq->lock) ->set err to all req's in fpq->io
->release(fpq->lock)
->acquire(fpq->lock)
->add req to fpq->io
After the userspace copy is done the request will be ended, but
req->out.h.error will remain uninitialized. Also the copy might block
despite being already aborted.
Fix both issues by not allowing the request to be queued on the fpq->io
list after fuse_abort_conn() has processed this list.
Reported-by: Pradeep P V K <pragalla@codeaurora.org>
Fixes: fd22d62ed0c3 ("fuse: no fc->lock for iqueue parts")
Cc: <stable@vger.kernel.org> # v4.2
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/fuse/dev.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index 1ff5a6b21db0..498a4fab4080 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -1310,6 +1310,15 @@ static ssize_t fuse_dev_do_read(struct fuse_dev *fud, struct file *file, goto restart; } spin_lock(&fpq->lock); + /* + * Must not put request on fpq->io queue after having been shut down by + * fuse_abort_conn() + */ + if (!fpq->connected) { + req->out.h.error = err = -ECONNABORTED; + goto out_end; + + } list_add(&req->list, &fpq->io); spin_unlock(&fpq->lock); cs->req = req; |