@@ -19,6 +19,7 @@
#include "tree-checker.h"
#include "disk-io.h"
#include "compression.h"
+#include "volumes.h"
/*
* Error message should follow the following format:
@@ -353,6 +354,103 @@ static int check_dir_item(struct btrfs_fs_info *fs_info,
return 0;
}
+__printf(4, 5)
+__cold
+static void block_group_err(const struct btrfs_fs_info *fs_info,
+ const struct extent_buffer *eb, int slot,
+ const char *fmt, ...)
+{
+ struct btrfs_key key;
+ struct va_format vaf;
+ va_list args;
+
+ btrfs_item_key_to_cpu(eb, &key, slot);
+ va_start(args, fmt);
+
+ vaf.fmt = fmt;
+ vaf.va = &args;
+
+ btrfs_crit(fs_info,
+ "corrupt %s: root=%llu block=%llu slot=%d bg_start=%llu bg_len=%llu, %pV",
+ btrfs_header_level(eb) == 0 ? "leaf" : "node",
+ btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot,
+ key.objectid, key.offset, &vaf);
+ va_end(args);
+}
+
+static int check_block_group_item(struct btrfs_fs_info *fs_info,
+ struct extent_buffer *leaf,
+ struct btrfs_key *key, int slot)
+{
+ struct btrfs_block_group_item bgi;
+ u32 item_size = btrfs_item_size_nr(leaf, slot);
+ u64 flags;
+ u64 type_flags;
+
+ /*
+ * Here we don't really care about unalignment since extent allocator
+ * can handle it.
+ * We care more about the size, as if one block group is larger than
+ * maximum size, it's must be some obvious corruption
+ */
+ if (key->offset > BTRFS_MAX_DATA_CHUNK_SIZE || key->offset == 0) {
+ block_group_err(fs_info, leaf, slot,
+ "invalid block group size, have %llu expect (0, %llu]",
+ key->offset, 10ULL * SZ_1G);
+ return -EUCLEAN;
+ }
+
+ if (item_size != sizeof(bgi)) {
+ block_group_err(fs_info, leaf, slot,
+ "invalid item size, have %u expect %lu",
+ item_size, sizeof(bgi));
+ return -EUCLEAN;
+ }
+
+ read_extent_buffer(leaf, &bgi, btrfs_item_ptr_offset(leaf, slot),
+ sizeof(bgi));
+ if (btrfs_block_group_chunk_objectid(&bgi) !=
+ BTRFS_FIRST_CHUNK_TREE_OBJECTID) {
+ block_group_err(fs_info, leaf, slot,
+ "invalid block group chunk objectid, have %llu expect %llu",
+ btrfs_block_group_chunk_objectid(&bgi),
+ BTRFS_FIRST_CHUNK_TREE_OBJECTID);
+ return -EUCLEAN;
+ }
+
+ if (btrfs_block_group_used(&bgi) > key->offset) {
+ block_group_err(fs_info, leaf, slot,
+ "invalid block group used, have %llu expect [0, %llu)",
+ btrfs_block_group_used(&bgi), key->offset);
+ return -EUCLEAN;
+ }
+
+ flags = btrfs_block_group_flags(&bgi);
+ if (hweight64(flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) > 1) {
+ block_group_err(fs_info, leaf, slot,
+"invalid profile flags, have 0x%llx (%lu bits set) expect no more than 1 bit set",
+ flags & BTRFS_BLOCK_GROUP_PROFILE_MASK,
+ hweight64(flags & BTRFS_BLOCK_GROUP_PROFILE_MASK));
+ return -EUCLEAN;
+ }
+
+ type_flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
+ if (type_flags != BTRFS_BLOCK_GROUP_DATA &&
+ type_flags != BTRFS_BLOCK_GROUP_METADATA &&
+ type_flags != BTRFS_BLOCK_GROUP_SYSTEM &&
+ type_flags != (BTRFS_BLOCK_GROUP_METADATA |
+ BTRFS_BLOCK_GROUP_DATA)) {
+ block_group_err(fs_info, leaf, slot,
+"invalid type flags, have 0x%llx (%lu bits set) expect either 0x%llx, 0x%llx, 0x%llu or 0x%llx",
+ type_flags, hweight64(type_flags),
+ BTRFS_BLOCK_GROUP_DATA, BTRFS_BLOCK_GROUP_METADATA,
+ BTRFS_BLOCK_GROUP_SYSTEM,
+ BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA);
+ return -EUCLEAN;
+ }
+ return 0;
+}
+
/*
* Common point to switch the item-specific validation.
*/
@@ -374,6 +472,9 @@ static int check_leaf_item(struct btrfs_fs_info *fs_info,
case BTRFS_XATTR_ITEM_KEY:
ret = check_dir_item(fs_info, leaf, key, slot);
break;
+ case BTRFS_BLOCK_GROUP_ITEM_KEY:
+ ret = check_block_group_item(fs_info, leaf, key, slot);
+ break;
}
return ret;
}
@@ -4690,7 +4690,7 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
if (type & BTRFS_BLOCK_GROUP_DATA) {
max_stripe_size = SZ_1G;
- max_chunk_size = 10 * max_stripe_size;
+ max_chunk_size = BTRFS_MAX_DATA_CHUNK_SIZE;
if (!devs_max)
devs_max = BTRFS_MAX_DEVS(info);
} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
@@ -11,6 +11,8 @@
#include <linux/btrfs.h>
#include "async-thread.h"
+#define BTRFS_MAX_DATA_CHUNK_SIZE (10ULL * SZ_1G)
+
extern struct mutex uuid_mutex;
#define BTRFS_STRIPE_LEN SZ_64K
As reported in https://bugzilla.kernel.org/show_bug.cgi?id=199849, a crafted image with invalid block group items could make free space cache code to cause panic. We could early detect such invalid block group item by checking: 1) Item size Fixed value. 2) Block group size (key.offset) We have a up limit on block group item (10G) 3) Chunk objectid Fixed value. 4) Type Only 4 valid type values, DATA, METADATA, SYSTEM and DATA|METADATA. No more than 1 bit set for profile type. 5) Used space No more than block group size. This should allow btrfs to detect and refuse to mount the crafted image. Reported-by: Xu Wen <wen.xu@gatech.edu> Signed-off-by: Qu Wenruo <wqu@suse.com> --- changelog: v2: Format change for if() code block, added one new line for each block. Use "hweight64() > 1" to detect profile error, replacing the bloated !(flags & MASK == 0 || hweight64() == 1) condition. v3: Allow special case for mixed block groups (type == (DATA | METADATA)). Use constant define for max data chunk size. --- fs/btrfs/tree-checker.c | 101 ++++++++++++++++++++++++++++++++++++++++ fs/btrfs/volumes.c | 2 +- fs/btrfs/volumes.h | 2 + 3 files changed, 104 insertions(+), 1 deletion(-)