Re: KMSAN: uninit-value in udf_get_pblock_spar15

[Jan Kara]

On Thu 24-09-20 02:26:29, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    c5a13b33 kmsan: clang-format core
> git tree:       https://github.com/google/kmsan.git master
> console output: https://syzkaller.appspot.com/x/log.txt?x=12152c81900000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=20f149ad694ba4be
> dashboard link: https://syzkaller.appspot.com/bug?extid=9991561e714f597095da
> compiler:       clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
> userspace arch: i386
> 
> Unfortunately, I don't have any reproducer for this issue yet.
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+9991561e714f597095da@xxxxxxxxxxxxxxxxxxxxxxxxx
> 
> =====================================================
> BUG: KMSAN: uninit-value in udf_get_pblock_spar15+0x4de/0x6b0 fs/udf/partition.c:138
> CPU: 0 PID: 27543 Comm: syz-executor.4 Not tainted 5.9.0-rc4-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Call Trace:
>  __dump_stack lib/dump_stack.c:77 [inline]
>  dump_stack+0x21c/0x280 lib/dump_stack.c:118
>  kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:122
>  __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:219
>  udf_get_pblock_spar15+0x4de/0x6b0 fs/udf/partition.c:138

I suppose this could result from UDF image where sparing table is larger
than a block. I've added check of the sparing table size to the mount path.

								Honza
-- 
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR