Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 fixes from Ted Ts'o:
 "Fix bugs that could cause kernel deadlocks or file system corruption
  while moving xattrs to expand the extended inode.

  Also add some sanity checks to the block group descriptors to make
  sure we don't end up overwriting the superblock"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: avoid deadlock when expanding inode size
  ext4: properly align shifted xattrs when expanding inodes
  ext4: fix xattr shifting when expanding inodes part 2
  ext4: fix xattr shifting when expanding inodes
  ext4: validate that metadata blocks do not overlap superblock
  ext4: reserve xattr index for the Hurd

1 files changed, 17 insertions, 1 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 1c593aa0218e..3ec8708989ca 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2211,6 +2211,7 @@ void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
 
 /* Called at mount-time, super-block is locked */
 static int ext4_check_descriptors(struct super_block *sb,
+				  ext4_fsblk_t sb_block,
 				  ext4_group_t *first_not_zeroed)
 {
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
@@ -2241,6 +2242,11 @@ static int ext4_check_descriptors(struct super_block *sb,
 			grp = i;
 
 		block_bitmap = ext4_block_bitmap(sb, gdp);
+		if (block_bitmap == sb_block) {
+			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+				 "Block bitmap for group %u overlaps "
+				 "superblock", i);
+		}
 		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 "
@@ -2248,6 +2254,11 @@ static int ext4_check_descriptors(struct super_block *sb,
 			return 0;
 		}
 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
+		if (inode_bitmap == sb_block) {
+			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+				 "Inode bitmap for group %u overlaps "
+				 "superblock", i);
+		}
 		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 "
@@ -2255,6 +2266,11 @@ static int ext4_check_descriptors(struct super_block *sb,
 			return 0;
 		}
 		inode_table = ext4_inode_table(sb, gdp);
+		if (inode_table == sb_block) {
+			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+				 "Inode table for group %u overlaps "
+				 "superblock", i);
+		}
 		if (inode_table < first_block ||
 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
@@ -3757,7 +3773,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 			goto failed_mount2;
 		}
 	}
-	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
+	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
 		ret = -EFSCORRUPTED;
 		goto failed_mount2;