| From f0d07a98a070bb5e443df19c3aa55693cbca9341 Mon Sep 17 00:00:00 2001 |
| From: Eric Biggers <ebiggers@google.com> |
| Date: Mon, 20 Jan 2020 14:31:59 -0800 |
| Subject: ubifs: don't trigger assertion on invalid no-key filename |
| |
| From: Eric Biggers <ebiggers@google.com> |
| |
| commit f0d07a98a070bb5e443df19c3aa55693cbca9341 upstream. |
| |
| If userspace provides an invalid fscrypt no-key filename which encodes a |
| hash value with any of the UBIFS node type bits set (i.e. the high 3 |
| bits), gracefully report ENOENT rather than triggering ubifs_assert(). |
| |
| Test case with kvm-xfstests shell: |
| |
| . fs/ubifs/config |
| . ~/xfstests/common/encrypt |
| dev=$(__blkdev_to_ubi_volume /dev/vdc) |
| ubiupdatevol $dev -t |
| mount $dev /mnt -t ubifs |
| mkdir /mnt/edir |
| xfs_io -c set_encpolicy /mnt/edir |
| rm /mnt/edir/_,,,,,DAAAAAAAAAAAAAAAAAAAAAAAAAA |
| |
| With the bug, the following assertion fails on the 'rm' command: |
| |
| [ 19.066048] UBIFS error (ubi0:0 pid 379): ubifs_assert_failed: UBIFS assert failed: !(hash & ~UBIFS_S_KEY_HASH_MASK), in fs/ubifs/key.h:170 |
| |
| Fixes: f4f61d2cc6d8 ("ubifs: Implement encrypted filenames") |
| Cc: <stable@vger.kernel.org> # v4.10+ |
| Link: https://lore.kernel.org/r/20200120223201.241390-5-ebiggers@kernel.org |
| Signed-off-by: Eric Biggers <ebiggers@google.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| fs/ubifs/dir.c | 2 ++ |
| 1 file changed, 2 insertions(+) |
| |
| --- a/fs/ubifs/dir.c |
| +++ b/fs/ubifs/dir.c |
| @@ -242,6 +242,8 @@ static struct dentry *ubifs_lookup(struc |
| if (nm.hash) { |
| ubifs_assert(c, fname_len(&nm) == 0); |
| ubifs_assert(c, fname_name(&nm) == NULL); |
| + if (nm.hash & ~UBIFS_S_KEY_HASH_MASK) |
| + goto done; /* ENOENT */ |
| dent_key_init_hash(c, &key, dir->i_ino, nm.hash); |
| err = ubifs_tnc_lookup_dh(c, &key, dent, nm.minor_hash); |
| } else { |
