63 lines
3.7 KiB
Plaintext
63 lines
3.7 KiB
Plaintext
URL: https://bugzilla.kernel.org/show_bug.cgi?id=156471
|
|
Lukas Lueg 2016-09-09 18:58:27 UTC
|
|
|
|
More news from the fuzzer and (up to now) the only news from UBSAN using
|
|
btrfs-progs v4.7-42-g56e9586. The attached image causes btrfsck to trigger
|
|
undefined behavior by dereferencing a ptr to a long unsigned int that was cast
|
|
from an uchar with no alignment guarantees.
|
|
|
|
UBSAN complains:
|
|
crc32c.c:75:19: runtime error: load of misaligned address 0x000001b3736c for
|
|
type 'long unsigned int', which requires 8 byte alignment
|
|
|
|
I've attached an image and a log, the behavior is triggered all the time and
|
|
unspecific, though.
|
|
|
|
AFAIC the problem is that *ptmp is cast from *data. This may actually not cause
|
|
the CPU to fault due to how *data is de-facto aligned by it's callers. The code
|
|
may still cause nose demons as the pure act of having *ptmp is undefined
|
|
behavior.
|
|
|
|
crc32c.c:75:19: runtime error: load of misaligned address 0x000001b3736c for type 'long unsigned int', which requires 8 byte alignment
|
|
0x000001b3736c: note: pointer points here
|
|
00 00 00 00 b7 0e 65 6c 64 61 40 4b a5 0d 0f ba 33 0c 75 27 00 00 02 00 00 00 00 00 01 00 00 00
|
|
^
|
|
#0 0x4f4308 in crc32c_intel /home/lukas/dev/btrfsfuzz/src-ubsan/crc32c.c:75
|
|
#1 0x4f43f3 in crc32c_le /home/lukas/dev/btrfsfuzz/src-ubsan/crc32c.c:221
|
|
#2 0x486c39 in __csum_tree_block_size /home/lukas/dev/btrfsfuzz/src-ubsan/disk-io.c:139
|
|
#3 0x486c39 in csum_tree_block_size /home/lukas/dev/btrfsfuzz/src-ubsan/disk-io.c:159
|
|
#4 0x486d48 in csum_tree_block_fs_info /home/lukas/dev/btrfsfuzz/src-ubsan/disk-io.c:174
|
|
#5 0x48ba29 in read_tree_block_fs_info /home/lukas/dev/btrfsfuzz/src-ubsan/disk-io.c:348
|
|
#6 0x48d48d in read_tree_block /home/lukas/dev/btrfsfuzz/src-ubsan/disk-io.h:112
|
|
#7 0x48d48d in btrfs_setup_chunk_tree_and_device_map /home/lukas/dev/btrfsfuzz/src-ubsan/disk-io.c:1210
|
|
#8 0x48d95b in __open_ctree_fd /home/lukas/dev/btrfsfuzz/src-ubsan/disk-io.c:1322
|
|
#9 0x48dd80 in open_ctree_fs_info /home/lukas/dev/btrfsfuzz/src-ubsan/disk-io.c:1381
|
|
#10 0x45011a in cmd_check /home/lukas/dev/btrfsfuzz/src-ubsan/cmds-check.c:11449
|
|
#11 0x40a799 in main /home/lukas/dev/btrfsfuzz/src-ubsan/btrfs.c:243
|
|
#12 0x7fdf11c96730 in __libc_start_main (/lib64/libc.so.6+0x20730)
|
|
#13 0x40a1e8 in _start (/home/lukas/dev/btrfsfuzz/bin-ubsan/bin/btrfs+0x40a1e8)
|
|
|
|
key (3472328296227680304 INODE_EXTREF 3472328296227680304)slot end outside of leaf 12360 > 3995
|
|
parent transid verify failed on 4227072 wanted 3472328296227680304 found 4
|
|
Ignoring transid failure
|
|
checking extents
|
|
Checking filesystem on ubsan_logs/id:000990,src:000816,op:flip1,pos:3845.img
|
|
UUID: b70e656c-6461-404b-a50d-0fba330c7527
|
|
key (3472328296227680304 INODE_EXTREF 3472328296227680304)slot end outside of leaf 12360 > 3995
|
|
Invalid key type(ROOT_ITEM) found in root(3472328296227680304)
|
|
ignoring invalid key
|
|
Invalid key type(ROOT_ITEM) found in root(3472328296227680304)
|
|
ignoring invalid key
|
|
Invalid key type(ROOT_ITEM) found in root(3472328296227680304)
|
|
ignoring invalid key
|
|
Invalid key type(ROOT_ITEM) found in root(3472328296227680304)
|
|
ignoring invalid key
|
|
key (3472328296227680304 INODE_EXTREF 3472328296227680304)slot end outside of leaf 12360 > 3995
|
|
key (3472328296227680304 INODE_EXTREF 3472328296227680304)slot end outside of leaf 12360 > 3995
|
|
key (3472328296227680304 INODE_EXTREF 3472328296227680304)slot end outside of leaf 12360 > 3995
|
|
key (3472328296227680304 INODE_EXTREF 3472328296227680304)slot end outside of leaf 12360 > 3995
|
|
key (3472328296227680304 INODE_EXTREF 3472328296227680304)slot end outside of leaf 12360 > 3995
|
|
bad block 4202496
|
|
Errors found in extent allocation tree or chunk allocation
|
|
key (3472328296227680304 INODE_EXTREF 3472328296227680304)slot end outside of leaf 12360 > 3995
|