URL: https://bugzilla.kernel.org/show_bug.cgi?id=154021
Lukas Lueg 2016-08-26 22:53:42 UTC

Created attachment 230361 [details]
Image triggering btrfsck to segv

The fuzzer hit again:

==32522==ERROR: AddressSanitizer: SEGV on unknown address 0x00027fff801c (pc
0x0000004a952e bp 0x7fff5222ce70 sp 0x7fff5222c600 T0)
    #0 0x4a952d in __asan_memcpy
(/home/lukas/dev/btrfsfuzz/bin-asan/bin/btrfs+0x4a952d)
    #1 0x66a323 in read_extent_buffer
/home/lukas/dev/btrfsfuzz/src-asan/extent_io.c:867:2
    #2 0x55ad25 in btrfs_node_key
/home/lukas/dev/btrfsfuzz/src-asan/./ctree.h:1668:2
    #3 0x58573b in check_fs_root
/home/lukas/dev/btrfsfuzz/src-asan/cmds-check.c:3748:3
    #4 0x544136 in check_fs_roots
/home/lukas/dev/btrfsfuzz/src-asan/cmds-check.c:3896:10
    #5 0x53d8c5 in cmd_check
/home/lukas/dev/btrfsfuzz/src-asan/cmds-check.c:11470:8
    #6 0x4f105f in main /home/lukas/dev/btrfsfuzz/src-asan/btrfs.c:243:8
    #7 0x7fea1bcb7730 in __libc_start_main (/lib64/libc.so.6+0x20730)
    #8 0x421238 in _start
(/home/lukas/dev/btrfsfuzz/bin-asan/bin/btrfs+0x421238)


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