diff options
| author | Miklos Szeredi <mszeredi@redhat.com> | 2019-01-16 10:27:59 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-12 19:47:24 +0100 |
| commit | 6ccc9e1128e50e518ecdf9e1b120c735e40de25a (patch) | |
| tree | 472de6aedac39abbc952a2ac967da9a9d37c88fd | |
| parent | f99027ab63bee0cbbde549ff663aef8b1c1944b5 (diff) | |
fuse: handle zero sized retrieve correctly
commit 97e1532ef81acb31c30f9e75bf00306c33a77812 upstream.
Dereferencing req->page_descs[0] will Oops if req->max_pages is zero.
Reported-by: syzbot+c1e36d30ee3416289cc0@syzkaller.appspotmail.com
Tested-by: syzbot+c1e36d30ee3416289cc0@syzkaller.appspotmail.com
Fixes: b2430d7567a3 ("fuse: add per-page descriptor <offset, length> to fuse_req")
Cc: <stable@vger.kernel.org> # v3.9
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/fuse/dev.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index c5e38061a48b..baaed4d05b22 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -1698,7 +1698,6 @@ static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode, req->in.h.nodeid = outarg->nodeid; req->in.numargs = 2; req->in.argpages = 1; - req->page_descs[0].offset = offset; req->end = fuse_retrieve_end; index = outarg->offset >> PAGE_SHIFT; @@ -1713,6 +1712,7 @@ static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode, this_num = min_t(unsigned, num, PAGE_SIZE - offset); req->pages[req->num_pages] = page; + req->page_descs[req->num_pages].offset = offset; req->page_descs[req->num_pages].length = this_num; req->num_pages++; |