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| author | Jan Kara <jack@suse.cz> | 2018-05-25 12:51:25 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2018-05-25 12:51:25 -0400 |
| commit | 4f2f76f751433908364ccff82f437a57d0e6e9b7 (patch) | |
| tree | 0b46191e9c1550811dbe0b02aa7818c04244d3bb /fs/ext4/resize.c | |
| parent | 8a2b307c21d4b290e3cbe33f768f194286d07c23 (diff) | |
| download | lwn-4f2f76f751433908364ccff82f437a57d0e6e9b7.tar.gz lwn-4f2f76f751433908364ccff82f437a57d0e6e9b7.zip | |
ext4: fix fencepost error in check for inode count overflow during resize
ext4_resize_fs() has an off-by-one bug when checking whether growing of
a filesystem will not overflow inode count. As a result it allows a
filesystem with 8192 inodes per group to grow to 64TB which overflows
inode count to 0 and makes filesystem unusable. Fix it.
Cc: stable@vger.kernel.org
Fixes: 3f8a6411fbada1fa482276591e037f3b1adcf55b
Reported-by: Jaco Kroon <jaco@uls.co.za>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Diffstat (limited to 'fs/ext4/resize.c')
| -rw-r--r-- | fs/ext4/resize.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index b6bec270a8e4..d792b7689d92 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1933,7 +1933,7 @@ retry: return 0; n_group = ext4_get_group_number(sb, n_blocks_count - 1); - if (n_group > (0xFFFFFFFFUL / EXT4_INODES_PER_GROUP(sb))) { + if (n_group >= (0xFFFFFFFFUL / EXT4_INODES_PER_GROUP(sb))) { ext4_warning(sb, "resize would cause inodes_count overflow"); return -EINVAL; } |