diff options
| author | Anirudh Rayabharam <mail@anirudhrb.com> | 2021-05-07 00:26:54 +0530 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2021-06-17 10:53:19 -0400 |
| commit | ce3aba43599f0b50adbebff133df8d08a3d5fffe (patch) | |
| tree | be466ea324adc1db0512031e2282c6551a2f7850 /fs/ext4 | |
| parent | 618f003199c6188e01472b03cdbba227f1dc5f24 (diff) | |
ext4: fix kernel infoleak via ext4_extent_header
Initialize eh_generation of struct ext4_extent_header to prevent leaking
info to userspace. Fixes KMSAN kernel-infoleak bug reported by syzbot at:
http://syzkaller.appspot.com/bug?id=78e9ad0e6952a3ca16e8234724b2fa92d041b9b8
Cc: stable@kernel.org
Reported-by: syzbot+2dcfeaf8cb49b05e8f1a@syzkaller.appspotmail.com
Fixes: a86c61812637 ("[PATCH] ext3: add extent map support")
Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com>
Link: https://lore.kernel.org/r/20210506185655.7118-1-mail@anirudhrb.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4')
| -rw-r--r-- | fs/ext4/extents.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index cbf37b2cf871..1293de50c8d4 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -825,6 +825,7 @@ void ext4_ext_tree_init(handle_t *handle, struct inode *inode) eh->eh_entries = 0; eh->eh_magic = EXT4_EXT_MAGIC; eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0)); + eh->eh_generation = 0; ext4_mark_inode_dirty(handle, inode); } @@ -1090,6 +1091,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode, neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0)); neh->eh_magic = EXT4_EXT_MAGIC; neh->eh_depth = 0; + neh->eh_generation = 0; /* move remainder of path[depth] to the new leaf */ if (unlikely(path[depth].p_hdr->eh_entries != @@ -1167,6 +1169,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode, neh->eh_magic = EXT4_EXT_MAGIC; neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0)); neh->eh_depth = cpu_to_le16(depth - i); + neh->eh_generation = 0; fidx = EXT_FIRST_INDEX(neh); fidx->ei_block = border; ext4_idx_store_pblock(fidx, oldblock); |