diff options
| author | Anirudh Rayabharam <mail@anirudhrb.com> | 2021-05-07 00:26:54 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-20 16:22:30 +0200 |
| commit | ce14bff239a107344b153bd6504a2f8165f672e9 (patch) | |
| tree | a494ea9406ea1aed0ae4f18dbe909837beac0ec0 /fs/ext4 | |
| parent | 12b4715523efc6844dc1fb1924441e9b990705fd (diff) | |
ext4: fix kernel infoleak via ext4_extent_header
commit ce3aba43599f0b50adbebff133df8d08a3d5fffe upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 50f98d6a4416..07ae78ba27a1 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -865,6 +865,7 @@ int 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); return 0; } @@ -1128,6 +1129,7 @@ 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 != @@ -1205,6 +1207,7 @@ 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); |