[PATCH 3.16 050/245] btrfs: validate type when reading a chunk

Ben Hutchings
2020-04-23T23:21:55Z

From: Gu Jinxiang <gujx@cn.fujitsu.com>

commit 315409b0098fb2651d86553f0436b70502b29bb2 upstream.

Reported in https://bugzilla.kernel.org/show_bug.cgi?id=199839, with an
image that has an invalid chunk type but does not return an error.

Add chunk type check in btrfs_check_chunk_valid, to detect the wrong
type combinations.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=199839
Reported-by: Xu Wen <wen.xu@gatech.edu>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Gu Jinxiang <gujx@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Backported to 4.4: Use root->fs_info instead of fs_info]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
fs/btrfs/volumes.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)

--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -5815,6 +5815,8 @@ static int btrfs_check_chunk_valid(struc
u16 num_stripes;
u16 sub_stripes;
u64 type;
+ u64 features;
+ bool mixed = false;

length = btrfs_chunk_length(leaf, chunk);
stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
@@ -5855,6 +5857,32 @@ static int btrfs_check_chunk_valid(struc
btrfs_chunk_type(leaf, chunk));
return -EIO;
}
+
+ if ((type & BTRFS_BLOCK_GROUP_TYPE_MASK) == 0) {
+ btrfs_err(root->fs_info, "missing chunk type flag: 0x%llx", type);
+ return -EIO;
+ }
+
+ if ((type & BTRFS_BLOCK_GROUP_SYSTEM) &&
+ (type & (BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA))) {
+ btrfs_err(root->fs_info,
+ "system chunk with data or metadata type: 0x%llx", type);
+ return -EIO;
+ }
+
+ features = btrfs_super_incompat_flags(root->fs_info->super_copy);
+ if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
+ mixed = true;
+
+ if (!mixed) {
+ if ((type & BTRFS_BLOCK_GROUP_METADATA) &&
+ (type & BTRFS_BLOCK_GROUP_DATA)) {
+ btrfs_err(root->fs_info,
+ "mixed chunk type in non-mixed mode: 0x%llx", type);
+ return -EIO;
+ }
+ }
+
if ((type & BTRFS_BLOCK_GROUP_RAID10 && sub_stripes != 2) ||
(type & BTRFS_BLOCK_GROUP_RAID1 && num_stripes < 1) ||
(type & BTRFS_BLOCK_GROUP_RAID5 && num_stripes < 2) ||