On Thu, Dec 5, 2019 at 6:45 AM syzbot <syzbot+c0d17fd100b00692b701@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: 818fcf71 Revert "kmsan: disable strscpy() optimization und.. > git tree: https://github.com/google/kmsan.git master > console output: https://syzkaller.appspot.com/x/log.txt?x=11b8bb7ae00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=fde150fb1e865232 > dashboard link: https://syzkaller.appspot.com/bug?extid=c0d17fd100b00692b701 > compiler: clang version 9.0.0 (/home/glider/llvm/clang > 80fee25776c2fb61e74c1ecb1a523375c2500b69) > > Unfortunately, I don't have any reproducer for this crash yet. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+c0d17fd100b00692b701@xxxxxxxxxxxxxxxxxxxxxxxxx #syz-fix: kmsan: disable strscpy() optimization under KMSAN This is a false positive that was accidentally sent upstream. > ===================================================== > BUG: KMSAN: uninit-value in seq_commit include/linux/seq_file.h:89 [inline] > BUG: KMSAN: uninit-value in proc_task_name+0x574/0x590 fs/proc/array.c:121 > CPU: 1 PID: 5202 Comm: ps Not tainted 5.4.0-rc8-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+0x1c9/0x220 lib/dump_stack.c:118 > kmsan_report+0x128/0x220 mm/kmsan/kmsan_report.c:108 > __msan_warning+0x57/0xa0 mm/kmsan/kmsan_instr.c:245 > seq_commit include/linux/seq_file.h:89 [inline] > proc_task_name+0x574/0x590 fs/proc/array.c:121 > do_task_stat+0x1a7b/0x3090 fs/proc/array.c:540 > proc_tgid_stat+0xbe/0xf0 fs/proc/array.c:632 > proc_single_show+0x1a8/0x2b0 fs/proc/base.c:756 > seq_read+0xac6/0x1d90 fs/seq_file.c:229 > __vfs_read+0x1a9/0xc90 fs/read_write.c:425 > vfs_read+0x359/0x6f0 fs/read_write.c:461 > ksys_read+0x265/0x430 fs/read_write.c:587 > __do_sys_read fs/read_write.c:597 [inline] > __se_sys_read+0x92/0xb0 fs/read_write.c:595 > __x64_sys_read+0x4a/0x70 fs/read_write.c:595 > do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:291 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > RIP: 0033:0x7fd34fa40310 > Code: 73 01 c3 48 8b 0d 28 4b 2b 00 31 d2 48 29 c2 64 89 11 48 83 c8 ff eb > ea 90 90 83 3d e5 a2 2b 00 00 75 10 b8 00 00 00 00 0f 05 <48> 3d 01 f0 ff > ff 73 31 c3 48 83 ec 08 e8 6e 8a 01 00 48 89 04 24 > RSP: 002b:00007ffc157facf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 > RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00007fd34fa40310 > RDX: 0000000000000fff RSI: 00007fd34ff0dd00 RDI: 0000000000000006 > RBP: 0000000000000fff R08: 0000000000000000 R09: 00007fd34fd08a10 > R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd34ff0dd00 > R13: 0000000001a59150 R14: 0000000000000005 R15: 0000000000000000 > > Local variable description: ----tcomm@proc_task_name > Variable was created at: > proc_task_name+0x8d/0x590 fs/proc/array.c:103 > proc_task_name+0x8d/0x590 fs/proc/array.c:103 > ===================================================== > > > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. -- Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Straße, 33 80636 München Geschäftsführer: Paul Manicle, Halimah DeLaine Prado Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg
