Commit 18db4b4e authored by Theodore Ts'o's avatar Theodore Ts'o

ext4: don't allow r/w mounts if metadata blocks overlap the superblock

If some metadata block, such as an allocation bitmap, overlaps the
superblock, it's very likely that if the file system is mounted
read/write, the results will not be pretty.  So disallow r/w mounts
for file systems corrupted in this particular way.
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
parent a45403b5
...@@ -2335,6 +2335,8 @@ static int ext4_check_descriptors(struct super_block *sb, ...@@ -2335,6 +2335,8 @@ static int ext4_check_descriptors(struct super_block *sb,
ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: " ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
"Block bitmap for group %u overlaps " "Block bitmap for group %u overlaps "
"superblock", i); "superblock", i);
if (!sb_rdonly(sb))
return 0;
} }
if (block_bitmap < first_block || block_bitmap > last_block) { if (block_bitmap < first_block || block_bitmap > last_block) {
ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: " ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
...@@ -2347,6 +2349,8 @@ static int ext4_check_descriptors(struct super_block *sb, ...@@ -2347,6 +2349,8 @@ static int ext4_check_descriptors(struct super_block *sb,
ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: " ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
"Inode bitmap for group %u overlaps " "Inode bitmap for group %u overlaps "
"superblock", i); "superblock", i);
if (!sb_rdonly(sb))
return 0;
} }
if (inode_bitmap < first_block || inode_bitmap > last_block) { if (inode_bitmap < first_block || inode_bitmap > last_block) {
ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: " ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
...@@ -2359,6 +2363,8 @@ static int ext4_check_descriptors(struct super_block *sb, ...@@ -2359,6 +2363,8 @@ static int ext4_check_descriptors(struct super_block *sb,
ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: " ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
"Inode table for group %u overlaps " "Inode table for group %u overlaps "
"superblock", i); "superblock", i);
if (!sb_rdonly(sb))
return 0;
} }
if (inode_table < first_block || if (inode_table < first_block ||
inode_table + sbi->s_itb_per_group - 1 > last_block) { inode_table + sbi->s_itb_per_group - 1 > last_block) {
......
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