URL: https://bugzilla.kernel.org/show_bug.cgi?id=155201
Lukas Lueg 2016-08-28 19:15:53 UTC 

Created attachment 230921 [details]
Image causing SIGFPE in btrfsck

News from the fuzzer. See the attached image to reproduce using btrfs-progs
v4.7-42-g56e9586.


[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
checking extents
Chunk[0, 4194304] existed.
Chunk[18446744073709551607, 228, 0]: length(1), offset(0), type(4160) mismatch
with block group[0, 192, 4194304]: offset(4194304), objectid(0), flags(2)

Program received signal SIGFPE, Arithmetic exception.
0x000000000042b178 in calc_stripe_length (type=4160, length=1, num_stripes=0)
at cmds-check.c:8018
8018			stripe_size /= num_stripes;
#0  0x000000000042b178 in calc_stripe_length (type=4160, length=1,
num_stripes=0) at cmds-check.c:8018
#1  0x000000000042b56d in check_chunk_refs (silent=0,
dev_extent_cache=0x7fffffffdd30, block_group_cache=0x7fffffffdd60,
chunk_rec=0x6b92c0) at cmds-check.c:8101
#2  check_chunks (chunk_cache=chunk_cache@entry=0x7fffffffdd80,
block_group_cache=block_group_cache@entry=0x7fffffffdd60,
dev_extent_cache=dev_extent_cache@entry=0x7fffffffdd30, good=good@entry=0x0,
bad=bad@entry=0x0, rebuild=rebuild@entry=0x0, silent=0) at cmds-check.c:8165
#3  0x000000000042bbdd in check_chunks_and_extents (root=root@entry=0x6b2cf0)
at cmds-check.c:8524
#4  0x000000000042e3cb in cmd_check (argc=<optimized out>, argv=<optimized
out>) at cmds-check.c:11430
#5  0x000000000040a416 in main (argc=2, argv=0x7fffffffe218) at btrfs.c:243