Message ID | 20190801163206.7906-1-stefanha@redhat.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | virtiofsd: fix req use-after-free in lo_flush() | expand |
* Stefan Hajnoczi (stefanha@redhat.com) wrote: > Isn't it funny that a commit trying to fix use-after-free introduced its > own use-after-free? > > fuse_reply_err() frees the request so we cannot call lo_data(req) > afterwards. > > Fixes: a5081fc6fc3603671383616127b3a5e169cf64ed > ("virtiofsd: introduce inode refcount to prevent use-after-free") > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Squashed into the top. Dave > --- > contrib/virtiofsd/passthrough_ll.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/contrib/virtiofsd/passthrough_ll.c b/contrib/virtiofsd/passthrough_ll.c > index ee8627446a..a81c01d0d1 100644 > --- a/contrib/virtiofsd/passthrough_ll.c > +++ b/contrib/virtiofsd/passthrough_ll.c > @@ -1969,9 +1969,8 @@ static void lo_flush(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi) > pthread_mutex_unlock(&inode->plock_mutex); > > res = close(dup(lo_fi_fd(req, fi))); > - fuse_reply_err(req, res == -1 ? errno : 0); > - > lo_inode_put(lo_data(req), &inode); > + fuse_reply_err(req, res == -1 ? errno : 0); > } > > static void lo_fsync(fuse_req_t req, fuse_ino_t ino, int datasync, > -- > 2.21.0 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
diff --git a/contrib/virtiofsd/passthrough_ll.c b/contrib/virtiofsd/passthrough_ll.c index ee8627446a..a81c01d0d1 100644 --- a/contrib/virtiofsd/passthrough_ll.c +++ b/contrib/virtiofsd/passthrough_ll.c @@ -1969,9 +1969,8 @@ static void lo_flush(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi) pthread_mutex_unlock(&inode->plock_mutex); res = close(dup(lo_fi_fd(req, fi))); - fuse_reply_err(req, res == -1 ? errno : 0); - lo_inode_put(lo_data(req), &inode); + fuse_reply_err(req, res == -1 ? errno : 0); } static void lo_fsync(fuse_req_t req, fuse_ino_t ino, int datasync,
Isn't it funny that a commit trying to fix use-after-free introduced its own use-after-free? fuse_reply_err() frees the request so we cannot call lo_data(req) afterwards. Fixes: a5081fc6fc3603671383616127b3a5e169cf64ed ("virtiofsd: introduce inode refcount to prevent use-after-free") Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> --- contrib/virtiofsd/passthrough_ll.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)