diff options
Diffstat (limited to 'ext4-fix-false-negative-and-false-positives.patch')
| -rw-r--r-- | ext4-fix-false-negative-and-false-positives.patch | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/ext4-fix-false-negative-and-false-positives.patch b/ext4-fix-false-negative-and-false-positives.patch new file mode 100644 index 000000000..2beba4f94 --- /dev/null +++ b/ext4-fix-false-negative-and-false-positives.patch @@ -0,0 +1,56 @@ +From 44de022c4382541cebdd6de4465d1f4f465ff1dd Mon Sep 17 00:00:00 2001 +From: Theodore Ts'o <tytso@mit.edu> +Date: Sun, 8 Jul 2018 19:35:02 -0400 +Subject: ext4: fix false negatives *and* false positives in + ext4_check_descriptors() + +Ext4_check_descriptors() was getting called before s_gdb_count was +initialized. So for file systems w/o the meta_bg feature, allocation +bitmaps could overlap the block group descriptors and ext4 wouldn't +notice. + +For file systems with the meta_bg feature enabled, there was a +fencepost error which would cause the ext4_check_descriptors() to +incorrectly believe that the block allocation bitmap overlaps with the +block group descriptor blocks, and it would reject the mount. + +Fix both of these problems. + +Signed-off-by: Theodore Ts'o <tytso@mit.edu> +Cc: stable@vger.kernel.org +--- + fs/ext4/super.c | 5 ++--- + 1 file changed, 2 insertions(+), 3 deletions(-) + +diff --git a/fs/ext4/super.c b/fs/ext4/super.c +index ba2396a7bd04..eff5c983e067 100644 +--- a/fs/ext4/super.c ++++ b/fs/ext4/super.c +@@ -2342,7 +2342,7 @@ static int ext4_check_descriptors(struct super_block *sb, + struct ext4_sb_info *sbi = EXT4_SB(sb); + ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block); + ext4_fsblk_t last_block; +- ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0) + 1; ++ ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0); + ext4_fsblk_t block_bitmap; + ext4_fsblk_t inode_bitmap; + ext4_fsblk_t inode_table; +@@ -4085,14 +4085,13 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) + goto failed_mount2; + } + } ++ sbi->s_gdb_count = db_count; + if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) { + ext4_msg(sb, KERN_ERR, "group descriptors corrupted!"); + ret = -EFSCORRUPTED; + goto failed_mount2; + } + +- sbi->s_gdb_count = db_count; +- + timer_setup(&sbi->s_err_report, print_daily_error_info, 0); + + /* Register extent status tree shrinker */ +-- +cgit 1.2-0.3.lf.el7 + |