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authorTheodore Ts'o <tytso@mit.edu>2018-06-13 23:08:26 -0400
committerTheodore Ts'o <tytso@mit.edu>2018-06-13 23:08:26 -0400
commit77260807d1170a8cf35dbb06e07461a655f67eee (patch)
treeb2390b2107ca0fead0013c5545c9d448d1a99103 /fs/ext4
parent819b23f1c501b17b9694325471789e6b5cc2d0d2 (diff)
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ext4: make sure bitmaps and the inode table don't overlap with bg descriptors
It's really bad when the allocation bitmaps and the inode table overlap with the block group descriptors, since it causes random corruption of the bg descriptors. So we really want to head those off at the pass. https://bugzilla.kernel.org/show_bug.cgi?id=199865 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
Diffstat (limited to 'fs/ext4')
-rw-r--r--fs/ext4/super.c25
1 files changed, 25 insertions, 0 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index c8b7b8302e90..c61675d62195 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2348,6 +2348,7 @@ 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 block_bitmap;
ext4_fsblk_t inode_bitmap;
ext4_fsblk_t inode_table;
@@ -2380,6 +2381,14 @@ static int ext4_check_descriptors(struct super_block *sb,
if (!sb_rdonly(sb))
return 0;
}
+ if (block_bitmap >= sb_block + 1 &&
+ block_bitmap <= last_bg_block) {
+ ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+ "Block bitmap for group %u overlaps "
+ "block group descriptors", i);
+ if (!sb_rdonly(sb))
+ return 0;
+ }
if (block_bitmap < first_block || block_bitmap > last_block) {
ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
"Block bitmap for group %u not in group "
@@ -2394,6 +2403,14 @@ static int ext4_check_descriptors(struct super_block *sb,
if (!sb_rdonly(sb))
return 0;
}
+ if (inode_bitmap >= sb_block + 1 &&
+ inode_bitmap <= last_bg_block) {
+ ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+ "Inode bitmap for group %u overlaps "
+ "block group descriptors", i);
+ if (!sb_rdonly(sb))
+ return 0;
+ }
if (inode_bitmap < first_block || inode_bitmap > last_block) {
ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
"Inode bitmap for group %u not in group "
@@ -2408,6 +2425,14 @@ static int ext4_check_descriptors(struct super_block *sb,
if (!sb_rdonly(sb))
return 0;
}
+ if (inode_table >= sb_block + 1 &&
+ inode_table <= last_bg_block) {
+ ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+ "Inode table for group %u overlaps "
+ "block group descriptors", i);
+ if (!sb_rdonly(sb))
+ return 0;
+ }
if (inode_table < first_block ||
inode_table + sbi->s_itb_per_group - 1 > last_block) {
ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "