Commit 40c3c409 authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba

btrfs: Add sanity check for EXTENT_DATA when reading out leaf

Add extra checks for item with EXTENT_DATA type.  This checks the
following thing:

0) Key offset
   All key offsets must be aligned to sectorsize.
   Inline extent must have 0 for key offset.

1) Item size
   Uncompressed inline file extent size must match item size.
   (Compressed inline file extent has no information about its on-disk size.)
   Regular/preallocated file extent size must be a fixed value.

2) Every member of regular file extent item
   Including alignment for bytenr and offset, possible value for
   compression/encryption/type.

3) Type/compression/encode must be one of the valid values.

This should be the most comprehensive and strict check in the context
of btrfs_item for EXTENT_DATA.
Signed-off-by: default avatarQu Wenruo <quwenruo.btrfs@gmx.com>
Reviewed-by: default avatarNikolay Borisov <nborisov@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
[ switch to BTRFS_FILE_EXTENT_TYPES, similar to what
  BTRFS_COMPRESS_TYPES does ]
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 7f43d4af
...@@ -549,6 +549,100 @@ static int check_tree_block_fsid(struct btrfs_fs_info *fs_info, ...@@ -549,6 +549,100 @@ static int check_tree_block_fsid(struct btrfs_fs_info *fs_info,
btrfs_header_level(eb) == 0 ? "leaf" : "node", \ btrfs_header_level(eb) == 0 ? "leaf" : "node", \
reason, btrfs_header_bytenr(eb), root->objectid, slot) reason, btrfs_header_bytenr(eb), root->objectid, slot)
static int check_extent_data_item(struct btrfs_root *root,
struct extent_buffer *leaf,
struct btrfs_key *key, int slot)
{
struct btrfs_file_extent_item *fi;
u32 sectorsize = root->fs_info->sectorsize;
u32 item_size = btrfs_item_size_nr(leaf, slot);
if (!IS_ALIGNED(key->offset, sectorsize)) {
CORRUPT("unaligned key offset for file extent",
leaf, root, slot);
return -EUCLEAN;
}
fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
if (btrfs_file_extent_type(leaf, fi) > BTRFS_FILE_EXTENT_TYPES) {
CORRUPT("invalid file extent type", leaf, root, slot);
return -EUCLEAN;
}
/*
* Support for new compression/encrption must introduce incompat flag,
* and must be caught in open_ctree().
*/
if (btrfs_file_extent_compression(leaf, fi) > BTRFS_COMPRESS_TYPES) {
CORRUPT("invalid file extent compression", leaf, root, slot);
return -EUCLEAN;
}
if (btrfs_file_extent_encryption(leaf, fi)) {
CORRUPT("invalid file extent encryption", leaf, root, slot);
return -EUCLEAN;
}
if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) {
/* Inline extent must have 0 as key offset */
if (key->offset) {
CORRUPT("inline extent has non-zero key offset",
leaf, root, slot);
return -EUCLEAN;
}
/* Compressed inline extent has no on-disk size, skip it */
if (btrfs_file_extent_compression(leaf, fi) !=
BTRFS_COMPRESS_NONE)
return 0;
/* Uncompressed inline extent size must match item size */
if (item_size != BTRFS_FILE_EXTENT_INLINE_DATA_START +
btrfs_file_extent_ram_bytes(leaf, fi)) {
CORRUPT("plaintext inline extent has invalid size",
leaf, root, slot);
return -EUCLEAN;
}
return 0;
}
/* Regular or preallocated extent has fixed item size */
if (item_size != sizeof(*fi)) {
CORRUPT(
"regluar or preallocated extent data item size is invalid",
leaf, root, slot);
return -EUCLEAN;
}
if (!IS_ALIGNED(btrfs_file_extent_ram_bytes(leaf, fi), sectorsize) ||
!IS_ALIGNED(btrfs_file_extent_disk_bytenr(leaf, fi), sectorsize) ||
!IS_ALIGNED(btrfs_file_extent_disk_num_bytes(leaf, fi), sectorsize) ||
!IS_ALIGNED(btrfs_file_extent_offset(leaf, fi), sectorsize) ||
!IS_ALIGNED(btrfs_file_extent_num_bytes(leaf, fi), sectorsize)) {
CORRUPT(
"regular or preallocated extent data item has unaligned value",
leaf, root, slot);
return -EUCLEAN;
}
return 0;
}
/*
* Common point to switch the item-specific validation.
*/
static int check_leaf_item(struct btrfs_root *root,
struct extent_buffer *leaf,
struct btrfs_key *key, int slot)
{
int ret = 0;
switch (key->type) {
case BTRFS_EXTENT_DATA_KEY:
ret = check_extent_data_item(root, leaf, key, slot);
break;
}
return ret;
}
static noinline int check_leaf(struct btrfs_root *root, static noinline int check_leaf(struct btrfs_root *root,
struct extent_buffer *leaf) struct extent_buffer *leaf)
{ {
...@@ -605,9 +699,13 @@ static noinline int check_leaf(struct btrfs_root *root, ...@@ -605,9 +699,13 @@ static noinline int check_leaf(struct btrfs_root *root,
* 1) key order * 1) key order
* 2) item offset and size * 2) item offset and size
* No overlap, no hole, all inside the leaf. * No overlap, no hole, all inside the leaf.
* 3) item content
* If possible, do comprehensive sanity check.
* NOTE: All checks must only rely on the item data itself.
*/ */
for (slot = 0; slot < nritems; slot++) { for (slot = 0; slot < nritems; slot++) {
u32 item_end_expected; u32 item_end_expected;
int ret;
btrfs_item_key_to_cpu(leaf, &key, slot); btrfs_item_key_to_cpu(leaf, &key, slot);
...@@ -650,6 +748,11 @@ static noinline int check_leaf(struct btrfs_root *root, ...@@ -650,6 +748,11 @@ static noinline int check_leaf(struct btrfs_root *root,
return -EUCLEAN; return -EUCLEAN;
} }
/* Check if the item size and content meet other criteria */
ret = check_leaf_item(root, leaf, &key, slot);
if (ret < 0)
return ret;
prev_key.objectid = key.objectid; prev_key.objectid = key.objectid;
prev_key.type = key.type; prev_key.type = key.type;
prev_key.offset = key.offset; prev_key.offset = key.offset;
......
...@@ -732,6 +732,7 @@ struct btrfs_balance_item { ...@@ -732,6 +732,7 @@ struct btrfs_balance_item {
#define BTRFS_FILE_EXTENT_INLINE 0 #define BTRFS_FILE_EXTENT_INLINE 0
#define BTRFS_FILE_EXTENT_REG 1 #define BTRFS_FILE_EXTENT_REG 1
#define BTRFS_FILE_EXTENT_PREALLOC 2 #define BTRFS_FILE_EXTENT_PREALLOC 2
#define BTRFS_FILE_EXTENT_TYPES 2
struct btrfs_file_extent_item { struct btrfs_file_extent_item {
/* /*
......
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