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| author | Amir Goldstein <amir73il@gmail.com> | 2018-09-28 21:00:48 +0300 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2018-10-04 14:49:10 +0200 |
| commit | 601350ff58d5415a001769532f6b8333820e5786 (patch) | |
| tree | 56ac78548e6345a2f5c3a6d96dd5d9fe304d69ed | |
| parent | 69383c5913a5d74b4aa7e2b78a5cf14ebfbba538 (diff) | |
| download | linux-601350ff58d5415a001769532f6b8333820e5786.tar.bz2 | |
ovl: fix access beyond unterminated strings
KASAN detected slab-out-of-bounds access in printk from overlayfs,
because string format used %*s instead of %.*s.
> BUG: KASAN: slab-out-of-bounds in string+0x298/0x2d0 lib/vsprintf.c:604
> Read of size 1 at addr ffff8801c36c66ba by task syz-executor2/27811
>
> CPU: 0 PID: 27811 Comm: syz-executor2 Not tainted 4.19.0-rc5+ #36
...
> printk+0xa7/0xcf kernel/printk/printk.c:1996
> ovl_lookup_index.cold.15+0xe8/0x1f8 fs/overlayfs/namei.c:689
Reported-by: syzbot+376cea2b0ef340db3dd4@syzkaller.appspotmail.com
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 359f392ca53e ("ovl: lookup index entry for copy up origin")
Cc: <stable@vger.kernel.org> # v4.13
| -rw-r--r-- | fs/overlayfs/namei.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c index f28711846dd6..9c0ca6a7becf 100644 --- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -686,7 +686,7 @@ struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper, index = NULL; goto out; } - pr_warn_ratelimited("overlayfs: failed inode index lookup (ino=%lu, key=%*s, err=%i);\n" + pr_warn_ratelimited("overlayfs: failed inode index lookup (ino=%lu, key=%.*s, err=%i);\n" "overlayfs: mount with '-o index=off' to disable inodes index.\n", d_inode(origin)->i_ino, name.len, name.name, err); |