On Mon, Aug 3, 2020 at 6:55 AM Dmitry Vyukov <dvyu...@google.com> wrote: > > On Mon, Aug 3, 2020 at 5:24 AM butt3rflyh4ck <butterflyhuan...@gmail.com> > wrote: > > > > Hi, syzkaller always get this crashes, I think this crash is not a > > bug, maybe some wrong configs > > cause, can you give me some help. thanks. > > > > log is below: > > ffff888063151a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > > ffff888063151a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > > ================================================================== > > Kernel panic - not syncing: panic_on_warn set ... > > CPU: 0 PID: 18555 Comm: syz-executor.2 Tainted: G B > > 5.8.0-rc7+ #3 > > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > > 1.10.2-1ubuntu1 04/01/2014 > > Call Trace: > > __dump_stack lib/dump_stack.c:77 [inline] > > dump_stack+0x18f/0x20d lib/dump_stack.c:118 > > panic+0x2e3/0x75c kernel/panic.c:231 > > end_report+0x4d/0x53 mm/kasan/report.c:104 > > __kasan_report mm/kasan/report.c:520 [inline] > > kasan_report.cold+0xd/0x37 mm/kasan/report.c:530 > > __fb_pad_aligned_buffer include/linux/fb.h:655 [inline] > > bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] > > bit_putcs+0xbb6/0xd20 drivers/video/fbdev/core/bitblit.c:185 > > fbcon_putcs+0x33c/0x3f0 drivers/video/fbdev/core/fbcon.c:1362 > > do_update_region+0x399/0x630 drivers/tty/vt/vt.c:683 > > redraw_screen+0x64c/0x770 drivers/tty/vt/vt.c:1029 > > vc_do_resize+0x1111/0x13f0 drivers/tty/vt/vt.c:1320 > > vt_ioctl+0x2037/0x2670 drivers/tty/vt/vt_ioctl.c:901 > > tty_ioctl+0x1019/0x15f0 drivers/tty/tty_io.c:2656 > > vfs_ioctl fs/ioctl.c:48 [inline] > > ksys_ioctl+0x11a/0x180 fs/ioctl.c:753 > > __do_sys_ioctl fs/ioctl.c:762 [inline] > > __se_sys_ioctl fs/ioctl.c:760 [inline] > > __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:760 > > do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 > > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > RIP: 0033:0x467129 > > Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 > > 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d > > 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 > > RSP: 002b:00007fb6f7854c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 > > RAX: ffffffffffffffda RBX: 000000000071e7c0 RCX: 0000000000467129 > > RDX: 0000000020000000 RSI: 000000000000560a RDI: 0000000000000003 > > RBP: 00000000004c0bd5 R08: 0000000000000000 R09: 0000000000000000 > > R10: 0000000000000000 R11: 0000000000000246 R12: 000000000076bf00 > > R13: 0000000000000000 R14: 000000000076bf00 R15: 00007ffd478a3fc0 > > Dumping ftrace buffer: > > (ftrace buffer empty) > > Kernel Offset: disabled > > Rebooting in 1 seconds.. > > +syzkaller mailing list, LKML > -syzkaller-bugs to BCC > > Hi butt3rflyh4ck, > > This is a very real kernel bug, see: > https://groups.google.com/forum/#!searchin/syzkaller-bugs/%22bit_putcs_aligned%22%7Csort:date > There are some reproducers available if you need them.
Or if you are asking about "Kernel panic - not syncing: panic_on_warn set" specifically, it happens because you set panic_on_warn=1 cmdline argument. But it only happens if there is a bug happened in the kernel before, it just turns some non-fatal bugs into fatal. So removing panic_on_warn=1 won't help. It's the right setting for syzkaller.