4.9-stable patches

added patches:
	ext4-don-t-allow-r-w-mounts-if-metadata-blocks-overlap-the-superblock.patch

diff --git a/queue-4.9/ext4-don-t-allow-r-w-mounts-if-metadata-blocks-overlap-the-superblock.patch b/queue-4.9/ext4-don-t-allow-r-w-mounts-if-metadata-blocks-overlap-the-superblock.patch
new file mode 100644 (file)
index 0000000..24df6db
--- /dev/null
+++ b/queue-4.9/ext4-don-t-allow-r-w-mounts-if-metadata-blocks-overlap-the-superblock.patch
@@ -0,0 +1,57 @@
+From 18db4b4e6fc31eda838dd1c1296d67dbcb3dc957 Mon Sep 17 00:00:00 2001
+From: Theodore Ts'o <tytso@mit.edu>
+Date: Thu, 29 Mar 2018 22:10:35 -0400
+Subject: ext4: don't allow r/w mounts if metadata blocks overlap the superblock
+
+From: Theodore Ts'o <tytso@mit.edu>
+
+commit 18db4b4e6fc31eda838dd1c1296d67dbcb3dc957 upstream.
+
+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.
+
+Backport notes:
+3.18.y is missing bc98a42c1f7d ("VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb)")
+and e462ec50cb5f ("VFS: Differentiate mount flags (MS_*) from internal superblock flags")
+so we simply use the sb MS_RDONLY check from pre bc98a42c1f7d in place of the sb_rdonly
+function used in the upstream variant of the patch.
+
+Signed-off-by: Theodore Ts'o <tytso@mit.edu>
+Cc: stable@vger.kernel.org
+Signed-off-by: Harsh Shandilya <harsh@prjkt.io>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ fs/ext4/super.c |    6 ++++++
+ 1 file changed, 6 insertions(+)
+
+--- a/fs/ext4/super.c
++++ b/fs/ext4/super.c
+@@ -2260,6 +2260,8 @@ static int ext4_check_descriptors(struct
+                       ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+                                "Block bitmap for group %u overlaps "
+                                "superblock", i);
++                      if (!(sb->s_flags & MS_RDONLY))
++                              return 0;
+               }
+               if (block_bitmap < first_block || block_bitmap > last_block) {
+                       ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+@@ -2272,6 +2274,8 @@ static int ext4_check_descriptors(struct
+                       ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+                                "Inode bitmap for group %u overlaps "
+                                "superblock", i);
++                      if (!(sb->s_flags & MS_RDONLY))
++                              return 0;
+               }
+               if (inode_bitmap < first_block || inode_bitmap > last_block) {
+                       ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+@@ -2284,6 +2288,8 @@ static int ext4_check_descriptors(struct
+                       ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+                                "Inode table for group %u overlaps "
+                                "superblock", i);
++                      if (!(sb->s_flags & MS_RDONLY))
++                              return 0;
+               }
+               if (inode_table < first_block ||
+                   inode_table + sbi->s_itb_per_group - 1 > last_block) {

diff --git a/queue-4.9/series b/queue-4.9/series
index d9dc5b2fa53de632bb143a427cfba8f189e76ddd..766e5420c059dfcc4ac147cc56d5836814baf16e 100644 (file)
--- a/queue-4.9/series
+++ b/queue-4.9/series
@@ -62,3 +62,4 @@ alsa-pcm-avoid-potential-races-between-oss-ioctls-and-read-write.patch
 alsa-pcm-return-ebusy-for-oss-ioctls-changing-busy-streams.patch
 alsa-pcm-fix-mutex-unbalance-in-oss-emulation-ioctls.patch
 alsa-pcm-fix-endless-loop-for-xrun-recovery-in-oss-emulation.patch
+ext4-don-t-allow-r-w-mounts-if-metadata-blocks-overlap-the-superblock.patch