diff options
| author | Kirill Tkhai <ktkhai@virtuozzo.com> | 2018-09-25 12:52:42 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-11-21 09:19:14 +0100 |
| commit | 569fda5c0183f36ea86185ca505fdf91dfcf4def (patch) | |
| tree | 9f5c9156e41cbced529a5c3ea321e2ad8ae09e1a | |
| parent | e8e17b1be3e804ae552677c8159825718d29f68a (diff) | |
fuse: Fix use-after-free in fuse_dev_do_write()
commit d2d2d4fb1f54eff0f3faa9762d84f6446a4bc5d0 upstream.
After we found req in request_find() and released the lock,
everything may happen with the req in parallel:
cpu0 cpu1
fuse_dev_do_write() fuse_dev_do_write()
req = request_find(fpq, ...) ...
spin_unlock(&fpq->lock) ...
... req = request_find(fpq, oh.unique)
... spin_unlock(&fpq->lock)
queue_interrupt(&fc->iq, req); ...
... ...
... ...
request_end(fc, req);
fuse_put_request(fc, req);
... queue_interrupt(&fc->iq, req);
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 46c34a348b0a ("fuse: no fc->lock for pqueue parts")
Cc: <stable@vger.kernel.org> # v4.2
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/fuse/dev.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index 675caed3e655..c2af8042f176 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -1877,16 +1877,20 @@ static ssize_t fuse_dev_do_write(struct fuse_dev *fud, /* Is it an interrupt reply? */ if (req->intr_unique == oh.unique) { + __fuse_get_request(req); spin_unlock(&fpq->lock); err = -EINVAL; - if (nbytes != sizeof(struct fuse_out_header)) + if (nbytes != sizeof(struct fuse_out_header)) { + fuse_put_request(fc, req); goto err_finish; + } if (oh.error == -ENOSYS) fc->no_interrupt = 1; else if (oh.error == -EAGAIN) queue_interrupt(&fc->iq, req); + fuse_put_request(fc, req); fuse_copy_finish(cs); return nbytes; |