[syzbot] BUG: unable to handle kernel paging request in bitfill_aligned (3)

syzbot syzbot+a168dbeaaa7778273c1b at syzkaller.appspotmail.com
Mon Jul 11 07:58:21 UTC 2022


Hello,

syzbot found the following issue on:

HEAD commit:    e35e5b6f695d Merge tag 'xsa-5.19-tag' of git://git.kernel...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17f49bbc080000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f3bf7765b1ebd721
dashboard link: https://syzkaller.appspot.com/bug?extid=a168dbeaaa7778273c1b
compiler:       Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2

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+a168dbeaaa7778273c1b at syzkaller.appspotmail.com

BUG: unable to handle page fault for address: ffffc90004331000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 11c00067 P4D 11c00067 PUD 11dc5067 PMD 1cffd067 PTE 0
Oops: 0002 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 11483 Comm: syz-executor.4 Not tainted 5.19.0-rc5-syzkaller-00056-ge35e5b6f695d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
RIP: 0010:memset64 arch/x86/include/asm/string_64.h:49 [inline]
RIP: 0010:memset_l include/linux/string.h:128 [inline]
RIP: 0010:bitfill_aligned+0x1ad/0x270 drivers/video/fbdev/core/sysfillrect.c:53
Code: 08 49 31 ef eb 66 e8 32 9c 05 fd 45 89 e6 4c 8b 64 24 10 44 89 f0 31 d2 f7 f3 89 c3 48 8b 6c 24 08 48 89 e8 4c 89 e7 48 89 d9 <f3> 48 ab 31 ff 44 89 ee e8 26 a0 05 fd 4d 85 ed 74 5f 4d 8d 24 dc
RSP: 0018:ffffc9000ae3f7e8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000001800 RCX: 0000000000001200
RDX: 0000000000000000 RSI: 0000000000000bca RDI: ffffc90004331000
RBP: 0000000000000000 R08: ffffffff8481e07e R09: 0000000000000040
R10: 0000000000000002 R11: ffff88803938d880 R12: ffffc9000432e000
R13: 0000000000000000 R14: 0000000000060000 R15: ffffffffffffffff
FS:  00007f8c16811700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc90004331000 CR3: 000000006dd66000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 sys_fillrect+0x5ce/0x7f0 drivers/video/fbdev/core/sysfillrect.c:281
 drm_fb_helper_sys_fillrect drivers/gpu/drm/drm_fb_helper.c:795 [inline]
 drm_fbdev_fb_fillrect+0x163/0x300 drivers/gpu/drm/drm_fb_helper.c:2310
 bit_clear_margins+0x3f1/0x6e0 drivers/video/fbdev/core/bitblit.c:232
 fbcon_clear_margins drivers/video/fbdev/core/fbcon.c:1304 [inline]
 fbcon_do_set_font+0xd7c/0x1330 drivers/video/fbdev/core/fbcon.c:2434
 fbcon_set_font+0xa9c/0xd80 drivers/video/fbdev/core/fbcon.c:2517
 con_font_set drivers/tty/vt/vt.c:4666 [inline]
 con_font_op+0xbe8/0x1070 drivers/tty/vt/vt.c:4710
 vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline]
 vt_ioctl+0x172e/0x1d00 drivers/tty/vt/vt_ioctl.c:752
 tty_ioctl+0x874/0xc60 drivers/tty/tty_io.c:2778
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7f8c15689109
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8c16811168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f8c1579bf60 RCX: 00007f8c15689109
RDX: 0000000020000040 RSI: 0000000000004b72 RDI: 0000000000000003
RBP: 00007f8c156e305d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffdfe77e39f R14: 00007f8c16811300 R15: 0000000000022000
 </TASK>
Modules linked in:
CR2: ffffc90004331000
---[ end trace 0000000000000000 ]---
RIP: 0010:memset64 arch/x86/include/asm/string_64.h:49 [inline]
RIP: 0010:memset_l include/linux/string.h:128 [inline]
RIP: 0010:bitfill_aligned+0x1ad/0x270 drivers/video/fbdev/core/sysfillrect.c:53
Code: 08 49 31 ef eb 66 e8 32 9c 05 fd 45 89 e6 4c 8b 64 24 10 44 89 f0 31 d2 f7 f3 89 c3 48 8b 6c 24 08 48 89 e8 4c 89 e7 48 89 d9 <f3> 48 ab 31 ff 44 89 ee e8 26 a0 05 fd 4d 85 ed 74 5f 4d 8d 24 dc
RSP: 0018:ffffc9000ae3f7e8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000001800 RCX: 0000000000001200
RDX: 0000000000000000 RSI: 0000000000000bca RDI: ffffc90004331000
RBP: 0000000000000000 R08: ffffffff8481e07e R09: 0000000000000040
R10: 0000000000000002 R11: ffff88803938d880 R12: ffffc9000432e000
R13: 0000000000000000 R14: 0000000000060000 R15: ffffffffffffffff
FS:  00007f8c16811700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc90004331000 CR3: 000000006dd66000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	08 49 31             	or     %cl,0x31(%rcx)
   3:	ef                   	out    %eax,(%dx)
   4:	eb 66                	jmp    0x6c
   6:	e8 32 9c 05 fd       	callq  0xfd059c3d
   b:	45 89 e6             	mov    %r12d,%r14d
   e:	4c 8b 64 24 10       	mov    0x10(%rsp),%r12
  13:	44 89 f0             	mov    %r14d,%eax
  16:	31 d2                	xor    %edx,%edx
  18:	f7 f3                	div    %ebx
  1a:	89 c3                	mov    %eax,%ebx
  1c:	48 8b 6c 24 08       	mov    0x8(%rsp),%rbp
  21:	48 89 e8             	mov    %rbp,%rax
  24:	4c 89 e7             	mov    %r12,%rdi
  27:	48 89 d9             	mov    %rbx,%rcx
* 2a:	f3 48 ab             	rep stos %rax,%es:(%rdi) <-- trapping instruction
  2d:	31 ff                	xor    %edi,%edi
  2f:	44 89 ee             	mov    %r13d,%esi
  32:	e8 26 a0 05 fd       	callq  0xfd05a05d
  37:	4d 85 ed             	test   %r13,%r13
  3a:	74 5f                	je     0x9b
  3c:	4d 8d 24 dc          	lea    (%r12,%rbx,8),%r12


---
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