BUG: unable to handle kernel paging request in bitfill_aligned

Status: upstream: reported on 2026/08/15 01:29
Reported-by: syzbot+6af5de424a53c7e0070e@syzkaller.appspotmail.com
First crash: 6d01h, last: 2d22h
Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream BUG: unable to handle kernel paging request in bitfill_aligned (4) fbdev 8 8 539d 620d 0/29 auto-obsoleted due to no activity on 2025/06/07 17:05
linux-4.14 BUG: unable to handle kernel paging request in bitfill_aligned 8 1 1463d 1463d 0/1 auto-obsoleted due to no activity on 2022/12/16 16:52
linux-4.19 BUG: unable to handle kernel paging request in bitfill_aligned 8 syz, C error 11 1284d 1714d 0/1 upstream: reported C repro on 2021/12/10 10:17
upstream BUG: unable to handle kernel paging request in bitfill_aligned (3) fbdev 8 syz, C unreliable 11 1459d 1501d 22/29 fixed on 2023/02/24 13:50
upstream BUG: unable to handle kernel paging request in bitfill_aligned (2) fbdev 21 syz, C inconclusive done 26 1694d 2102d 20/29 fixed on 2022/05/13 11:13
upstream BUG: unable to handle kernel paging request in bitfill_aligned fbdev 8 1 2293d 2291d 0/29 closed as dup on 2020/08/16 15:35

Sample crash report:
BUG: unable to handle page fault for address: ffffc900046b9000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 17400067 P4D 17400067 PUD 17622067 PMD 248e3067 PTE 0
Oops: 0002 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 16999 Comm: syz.4.2547 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:memset64 arch/x86/include/asm/string_64.h:64 [inline]
RIP: 0010:memset_l include/linux/string.h:169 [inline]
RIP: 0010:bitfill_aligned+0x18e/0x230 drivers/video/fbdev/core/sysfillrect.c:53
Code: 48 31 c3 49 89 1e eb 73 e8 af d8 2c fd 44 89 e3 4c 8b 64 24 08 4c 8b 2c 24 89 d8 31 d2 f7 f5 89 c3 4c 89 e0 4c 89 ef 48 89 d9 <f3> 48 ab 31 ff 44 89 fe e8 e5 db 2c fd 4d 85 ff 74 3a e8 7b d8 2c
RSP: 0018:ffffc900036672e8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 000000000000017a RCX: 000000000000017a
RDX: 0000000000000000 RSI: 00000000000130ac RDI: ffffc900046b9000
RBP: 0000000000000040 R08: 0000000000005e80 R09: 0000000000000040
R10: 0000000000000001 R11: 0000000000000002 R12: 0000000000000000
R13: ffffc900046b9000 R14: ffffffffffffffff R15: 0000000000000000
FS:  00007fbc808396c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc900046b9000 CR3: 00000000285ab000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 sys_fillrect+0x5e0/0x7d0 drivers/video/fbdev/core/sysfillrect.c:281
 drm_fb_helper_sys_fillrect+0x2e/0x510 drivers/gpu/drm/drm_fb_helper.c:834
 bit_clear+0x15f/0x1f0 drivers/video/fbdev/core/bitblit.c:73
 __fbcon_clear+0x4c3/0x820 drivers/video/fbdev/core/fbcon.c:1283
 fbcon_scroll+0x43e/0x760 drivers/video/fbdev/core/fbcon.c:1851
 con_scroll+0x50e/0x7a0 drivers/tty/vt/vt.c:630
 csi_M+0xa8/0x140 drivers/tty/vt/vt.c:2055
 do_con_trol drivers/tty/vt/vt.c:2463 [inline]
 do_con_write+0x4289/0x6c40 drivers/tty/vt/vt.c:2951
 con_write+0x1f/0x40 drivers/tty/vt/vt.c:3295
 process_output_block drivers/tty/n_tty.c:586 [inline]
 n_tty_write+0xd61/0x11e0 drivers/tty/n_tty.c:2377
 do_tty_write drivers/tty/tty_io.c:1018 [inline]
 file_tty_write+0x4c7/0x840 drivers/tty/tty_io.c:1089
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x482/0x9a0 fs/read_write.c:584
 ksys_write+0x14d/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fbc7f99e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fbc80839028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fbc7fc26180 RCX: 00007fbc7f99e0d9
RDX: 0000000000001006 RSI: 0000200000000000 RDI: 0000000000000008
RBP: 00007fbc7fa35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbc7fc26218 R14: 00007fbc7fc26180 R15: 00007ffc903699a8
 </TASK>
Modules linked in:
CR2: ffffc900046b9000
---[ end trace 0000000000000000 ]---
RIP: 0010:memset64 arch/x86/include/asm/string_64.h:64 [inline]
RIP: 0010:memset_l include/linux/string.h:169 [inline]
RIP: 0010:bitfill_aligned+0x18e/0x230 drivers/video/fbdev/core/sysfillrect.c:53
Code: 48 31 c3 49 89 1e eb 73 e8 af d8 2c fd 44 89 e3 4c 8b 64 24 08 4c 8b 2c 24 89 d8 31 d2 f7 f5 89 c3 4c 89 e0 4c 89 ef 48 89 d9 <f3> 48 ab 31 ff 44 89 fe e8 e5 db 2c fd 4d 85 ff 74 3a e8 7b d8 2c
RSP: 0018:ffffc900036672e8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 000000000000017a RCX: 000000000000017a
RDX: 0000000000000000 RSI: 00000000000130ac RDI: ffffc900046b9000
RBP: 0000000000000040 R08: 0000000000005e80 R09: 0000000000000040
R10: 0000000000000001 R11: 0000000000000002 R12: 0000000000000000
R13: ffffc900046b9000 R14: ffffffffffffffff R15: 0000000000000000
FS:  00007fbc808396c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc900046b9000 CR3: 00000000285ab000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	48 31 c3             	xor    %rax,%rbx
   3:	49 89 1e             	mov    %rbx,(%r14)
   6:	eb 73                	jmp    0x7b
   8:	e8 af d8 2c fd       	call   0xfd2cd8bc
   d:	44 89 e3             	mov    %r12d,%ebx
  10:	4c 8b 64 24 08       	mov    0x8(%rsp),%r12
  15:	4c 8b 2c 24          	mov    (%rsp),%r13
  19:	89 d8                	mov    %ebx,%eax
  1b:	31 d2                	xor    %edx,%edx
  1d:	f7 f5                	div    %ebp
  1f:	89 c3                	mov    %eax,%ebx
  21:	4c 89 e0             	mov    %r12,%rax
  24:	4c 89 ef             	mov    %r13,%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 fe             	mov    %r15d,%esi
  32:	e8 e5 db 2c fd       	call   0xfd2cdc1c
  37:	4d 85 ff             	test   %r15,%r15
  3a:	74 3a                	je     0x76
  3c:	e8                   	.byte 0xe8
  3d:	7b d8                	jnp    0x17
  3f:	2c                   	.byte 0x2c

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/18 04:32 linux-6.1.y e4f7d8be268e 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan BUG: unable to handle kernel paging request in bitfill_aligned
2026/08/15 01:29 linux-6.1.y e4f7d8be268e 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in bitfill_aligned
* Struck through repros no longer work on HEAD.