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FAILED: patch "[PATCH] ext4: don't allow r/w mounts if metadata blocks overlap the" failed to apply to 4.4-stable tree

PATCH [email protected] 1 participant 1 message Apr 20, 2018

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The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

Quoted 1 line

From 18db4b4e6fc31eda838dd1c1296d67dbcb3dc957 Mon Sep 17 00:00:00 2001

From: Theodore Ts'o <[email protected]>
Date: Thu, 29 Mar 2018 22:10:35 -0400
Subject: [PATCH] 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 <[email protected]>
Cc [email protected]
fs/ext4/super.c +6 -0
index 7cd022c344d1..edcfe6956eba 100644
@@ -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) {