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authorTheodore Ts'o <tytso@mit.edu>2018-03-30 04:10:35 +0200
committerTheodore Ts'o <tytso@mit.edu>2018-03-30 04:10:35 +0200
commit18db4b4e6fc31eda838dd1c1296d67dbcb3dc957 (patch)
tree0a87b79441cdac031e35498a4cef0969c9646fe5 /fs/ext4
parentext4: always initialize the crc32c checksum driver (diff)
downloadlinux-18db4b4e6fc31eda838dd1c1296d67dbcb3dc957.tar.xz
linux-18db4b4e6fc31eda838dd1c1296d67dbcb3dc957.zip
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: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org
Diffstat (limited to 'fs/ext4')
-rw-r--r--fs/ext4/super.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 7cd022c344d1..edcfe6956eba 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2335,6 +2335,8 @@ static int ext4_check_descriptors(struct super_block *sb,
ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
"Block bitmap for group %u overlaps "
"superblock", i);
+ if (!sb_rdonly(sb))
+ return 0;
}
if (block_bitmap < first_block || block_bitmap > last_block) {
ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
@@ -2347,6 +2349,8 @@ static int ext4_check_descriptors(struct super_block *sb,
ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
"Inode bitmap for group %u overlaps "
"superblock", i);
+ if (!sb_rdonly(sb))
+ return 0;
}
if (inode_bitmap < first_block || inode_bitmap > last_block) {
ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
@@ -2359,6 +2363,8 @@ static int ext4_check_descriptors(struct super_block *sb,
ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
"Inode table for group %u overlaps "
"superblock", i);
+ if (!sb_rdonly(sb))
+ return 0;
}
if (inode_table < first_block ||
inode_table + sbi->s_itb_per_group - 1 > last_block) {