diff options
author | Qu Wenruo <wqu@suse.com> | 2018-02-14 16:15:46 +0100 |
---|---|---|
committer | David Sterba <dsterba@suse.com> | 2018-02-14 16:20:30 +0100 |
commit | 54246115ba343d07651eff05e8bf7d159a897670 (patch) | |
tree | d316b32ed61f736ef292b879da1ef673d6977e87 /check | |
parent | e6477462d313b03feed68e828484abc807d7e928 (diff) |
btrfs-progs: btrfs-progs: Fix read beyond boundary bug in build_roots_info_cache()
This bug is exposed by fsck-test with D=asan, hit by test case 020, with
the following error report:
=================================================================
==10740==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x621000061580 at pc 0x56051f0db6cd bp 0x7ffe170f3e20 sp 0x7ffe170f3e10
READ of size 1 at 0x621000061580 thread T0
#0 0x56051f0db6cc in btrfs_extent_inline_ref_type /home/adam/btrfs/btrfs-progs/ctree.h:1727
#1 0x56051f13b669 in build_roots_info_cache /home/adam/btrfs/btrfs-progs/cmds-check.c:14306
#2 0x56051f13c86a in repair_root_items /home/adam/btrfs/btrfs-progs/cmds-check.c:14450
#3 0x56051f13ea89 in cmd_check /home/adam/btrfs/btrfs-progs/cmds-check.c:14965
#4 0x56051efe75bb in main /home/adam/btrfs/btrfs-progs/btrfs.c:302
#5 0x7f04ddbb0f49 in __libc_start_main (/usr/lib/libc.so.6+0x20f49)
#6 0x56051efe68c9 in _start (/home/adam/btrfs/btrfs-progs/btrfs+0x5b8c9)
0x621000061580 is located 0 bytes to the right of 4224-byte region [0x621000060500,0x621000061580)
allocated by thread T0 here:
#0 0x7f04ded50ce1 in __interceptor_calloc /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cc:70
#1 0x56051f04685e in __alloc_extent_buffer /home/adam/btrfs/btrfs-progs/extent_io.c:553
#2 0x56051f047563 in alloc_extent_buffer /home/adam/btrfs/btrfs-progs/extent_io.c:687
#3 0x56051efff1d1 in btrfs_find_create_tree_block /home/adam/btrfs/btrfs-progs/disk-io.c:187
#4 0x56051f000133 in read_tree_block /home/adam/btrfs/btrfs-progs/disk-io.c:327
#5 0x56051efeddb8 in read_node_slot /home/adam/btrfs/btrfs-progs/ctree.c:652
#6 0x56051effb0d9 in btrfs_next_leaf /home/adam/btrfs/btrfs-progs/ctree.c:2853
#7 0x56051f13b343 in build_roots_info_cache /home/adam/btrfs/btrfs-progs/cmds-check.c:14267
#8 0x56051f13c86a in repair_root_items /home/adam/btrfs/btrfs-progs/cmds-check.c:14450
#9 0x56051f13ea89 in cmd_check /home/adam/btrfs/btrfs-progs/cmds-check.c:14965
#10 0x56051efe75bb in main /home/adam/btrfs/btrfs-progs/btrfs.c:302
#11 0x7f04ddbb0f49 in __libc_start_main (/usr/lib/libc.so.6+0x20f49)
It's completely possible that one extent/metadata item has no inline
reference, while build_roots_info_cache() doesn't have such check.
Fix it by checking @iref against item end to avoid such problem.
Issue: #92
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'check')
-rw-r--r-- | check/main.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/check/main.c b/check/main.c index c051a862..97baae58 100644 --- a/check/main.c +++ b/check/main.c @@ -9054,6 +9054,7 @@ static int build_roots_info_cache(struct btrfs_fs_info *info) struct btrfs_key found_key; struct btrfs_extent_item *ei; struct btrfs_extent_inline_ref *iref; + unsigned long item_end; int slot = path.slots[0]; int type; u64 flags; @@ -9082,6 +9083,7 @@ static int build_roots_info_cache(struct btrfs_fs_info *info) ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); flags = btrfs_extent_flags(leaf, ei); + item_end = (unsigned long)ei + btrfs_item_size_nr(leaf, slot); if (found_key.type == BTRFS_EXTENT_ITEM_KEY && !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) @@ -9099,6 +9101,15 @@ static int build_roots_info_cache(struct btrfs_fs_info *info) } /* + * It's a valid extent/metadata item that has no inline ref, + * but SHARED_BLOCK_REF or other shared references. + * So we need to do extra check to avoid reading beyond leaf + * boudnary. + */ + if ((unsigned long)iref >= item_end) + goto next; + + /* * For a root extent, it must be of the following type and the * first (and only one) iref in the item. */ |