[moderation] [kernel?] BUG: unable to handle kernel paging request in cirrus_primary_plane_helper_atomic_update
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syzbot
Aug 9, 2026, 8:14:27 PM (10 hours ago) Aug 9
to syzkaller-upst...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 848acc8ffe1b Merge tag 'fsverity-for-linus' of git://git.k..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=112fb649580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f221a1b5d497ed15
dashboard link: https://syzkaller.appspot.com/bug?extid=25c2e33af9e4356a3f10
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
userspace arch: i386
CC: [b...@alien8.de dave....@linux.intel.com h...@zytor.com linux-...@vger.kernel.org mi...@redhat.com tg...@kernel.org x...@kernel.org]
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-848acc8f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/31f94fe4d67f/vmlinux-848acc8f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/391ba15cbf42/bzImage-848acc8f.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+25c2e3...@syzkaller.appspotmail.com
BUG: unable to handle page fault for address: ffffc90007196000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 1bc00067 P4D 1bc00067 PUD 1d293067 PMD 22034067 PTE 0
Oops: Oops: 0002 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 6226 Comm: syz.2.83 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:rep_movs arch/x86/lib/iomem.c:13 [inline]
RIP: 0010:string_memcpy_toio arch/x86/lib/iomem.c:64 [inline]
RIP: 0010:memcpy_toio+0x87/0xe0 arch/x86/lib/iomem.c:110
Code: b8 fc 49 89 dd 31 ff 41 83 e5 02 4c 89 ee e8 f0 28 b8 fc 4d 85 ed 75 33 e8 46 2e b8 fc 48 89 e9 48 89 df 4c 89 e6 48 c1 e9 02 <f3> a5 40 f6 c5 02 74 02 66 a5 40 f6 c5 01 74 01 a4 e8 23 2e b8 fc
RSP: 0018:ffffc9000782f5c0 EFLAGS: 00010206
RAX: 0000000000000000 RBX: ffffc90007195d20 RCX: 00000000000000d8
RDX: ffff88802232ca80 RSI: ffffc90004051f60 RDI: ffffc90007196000
RBP: 0000000000000640 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 000000000000001e R12: ffffc90004051c80
R13: 0000000000000000 R14: ffffc90007195d20 R15: 0000000000000640
FS: 0000000000000000(0000) GS:ffff888096bdf000(0063) knlGS:0000000056b41480
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: ffffc90007196000 CR3: 0000000070295000 CR4: 0000000000352ef0
Call Trace:
<TASK>
iosys_map_memcpy_to include/linux/iosys-map.h:285 [inline]
drm_fb_memcpy+0x459/0x620 drivers/gpu/drm/drm_format_helper.c:442
cirrus_primary_plane_helper_atomic_update+0xb1d/0xfe0 drivers/gpu/drm/tiny/cirrus-qemu.c:358
drm_atomic_helper_commit_planes+0x497/0xf10 drivers/gpu/drm/drm_atomic_helper.c:3038
drm_atomic_helper_commit_tail+0x7f/0x130 drivers/gpu/drm/drm_atomic_helper.c:1989
commit_tail+0x338/0x430 drivers/gpu/drm/drm_atomic_helper.c:2074
drm_atomic_helper_commit+0x303/0x380 drivers/gpu/drm/drm_atomic_helper.c:2312
drm_atomic_commit+0x230/0x300 drivers/gpu/drm/drm_atomic.c:1789
drm_client_modeset_commit_atomic+0x6a6/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1104
drm_client_modeset_commit_locked+0x14d/0x580 drivers/gpu/drm/drm_client_modeset.c:1207
drm_client_modeset_commit+0x4f/0x80 drivers/gpu/drm/drm_client_modeset.c:1233
__drm_fb_helper_restore_fbdev_mode_unlocked.part.0+0x137/0x160 drivers/gpu/drm/drm_fb_helper.c:138
__drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:126 [inline]
drm_fb_helper_restore_fbdev_mode_unlocked+0x93/0xc0 drivers/gpu/drm/drm_fb_helper.c:169
drm_fbdev_client_restore+0x1b/0x30 drivers/gpu/drm/clients/drm_fbdev_client.c:45
drm_client_dev_restore+0x205/0x2a0 drivers/gpu/drm/drm_client_event.c:118
drm_lastclose drivers/gpu/drm/drm_file.c:408 [inline]
drm_release+0x2c6/0x360 drivers/gpu/drm/drm_file.c:441
__fput+0x3ff/0xb50 fs/file_table.c:512
task_work_run+0x150/0x240 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
exit_to_user_mode_loop+0x1d8/0x6f0 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
__do_fast_syscall_32+0x701/0x970 arch/x86/entry/syscall_32.c:310
do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f15fec
Code: Unable to access opcode bytes at 0xf7f15fc2.
RSP: 002b:00000000ffd3840c EFLAGS: 00000202
ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 000000000000001e
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
Modules linked in:
CR2: ffffc90007196000
---[ end trace 0000000000000000 ]---
RIP: 0010:rep_movs arch/x86/lib/iomem.c:13 [inline]
RIP: 0010:string_memcpy_toio arch/x86/lib/iomem.c:64 [inline]
RIP: 0010:memcpy_toio+0x87/0xe0 arch/x86/lib/iomem.c:110
Code: b8 fc 49 89 dd 31 ff 41 83 e5 02 4c 89 ee e8 f0 28 b8 fc 4d 85 ed 75 33 e8 46 2e b8 fc 48 89 e9 48 89 df 4c 89 e6 48 c1 e9 02 <f3> a5 40 f6 c5 02 74 02 66 a5 40 f6 c5 01 74 01 a4 e8 23 2e b8 fc
RSP: 0018:ffffc9000782f5c0 EFLAGS: 00010206
RAX: 0000000000000000 RBX: ffffc90007195d20 RCX: 00000000000000d8
RDX: ffff88802232ca80 RSI: ffffc90004051f60 RDI: ffffc90007196000
RBP: 0000000000000640 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 000000000000001e R12: ffffc90004051c80
R13: 0000000000000000 R14: ffffc90007195d20 R15: 0000000000000640
FS: 0000000000000000(0000) GS:ffff888096bdf000(0063) knlGS:0000000056b41480
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f7f16000 CR3: 0000000070295000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
0: b8 fc 49 89 dd mov $0xdd8949fc,%eax
5: 31 ff xor %edi,%edi
7: 41 83 e5 02 and $0x2,%r13d
b: 4c 89 ee mov %r13,%rsi
e: e8 f0 28 b8 fc call 0xfcb82903
13: 4d 85 ed test %r13,%r13
16: 75 33 jne 0x4b
18: e8 46 2e b8 fc call 0xfcb82e63
1d: 48 89 e9 mov %rbp,%rcx
20: 48 89 df mov %rbx,%rdi
23: 4c 89 e6 mov %r12,%rsi
26: 48 c1 e9 02 shr $0x2,%rcx
* 2a: f3 a5 rep movsl %ds:(%rsi),%es:(%rdi) <-- trapping instruction
2c: 40 f6 c5 02 test $0x2,%bpl
30: 74 02 je 0x34
32: 66 a5 movsw %ds:(%rsi),%es:(%rdi)
34: 40 f6 c5 01 test $0x1,%bpl
38: 74 01 je 0x3b
3a: a4 movsb %ds:(%rsi),%es:(%rdi)
3b: e8 23 2e b8 fc call 0xfcb82e63
---
This report 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 syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot found the following issue on:
HEAD commit: 848acc8ffe1b Merge tag 'fsverity-for-linus' of git://git.k..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=112fb649580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f221a1b5d497ed15
dashboard link: https://syzkaller.appspot.com/bug?extid=25c2e33af9e4356a3f10
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
userspace arch: i386
CC: [b...@alien8.de dave....@linux.intel.com h...@zytor.com linux-...@vger.kernel.org mi...@redhat.com tg...@kernel.org x...@kernel.org]
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-848acc8f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/31f94fe4d67f/vmlinux-848acc8f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/391ba15cbf42/bzImage-848acc8f.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+25c2e3...@syzkaller.appspotmail.com
BUG: unable to handle page fault for address: ffffc90007196000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 1bc00067 P4D 1bc00067 PUD 1d293067 PMD 22034067 PTE 0
Oops: Oops: 0002 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 6226 Comm: syz.2.83 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:rep_movs arch/x86/lib/iomem.c:13 [inline]
RIP: 0010:string_memcpy_toio arch/x86/lib/iomem.c:64 [inline]
RIP: 0010:memcpy_toio+0x87/0xe0 arch/x86/lib/iomem.c:110
Code: b8 fc 49 89 dd 31 ff 41 83 e5 02 4c 89 ee e8 f0 28 b8 fc 4d 85 ed 75 33 e8 46 2e b8 fc 48 89 e9 48 89 df 4c 89 e6 48 c1 e9 02 <f3> a5 40 f6 c5 02 74 02 66 a5 40 f6 c5 01 74 01 a4 e8 23 2e b8 fc
RSP: 0018:ffffc9000782f5c0 EFLAGS: 00010206
RAX: 0000000000000000 RBX: ffffc90007195d20 RCX: 00000000000000d8
RDX: ffff88802232ca80 RSI: ffffc90004051f60 RDI: ffffc90007196000
RBP: 0000000000000640 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 000000000000001e R12: ffffc90004051c80
R13: 0000000000000000 R14: ffffc90007195d20 R15: 0000000000000640
FS: 0000000000000000(0000) GS:ffff888096bdf000(0063) knlGS:0000000056b41480
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: ffffc90007196000 CR3: 0000000070295000 CR4: 0000000000352ef0
Call Trace:
<TASK>
iosys_map_memcpy_to include/linux/iosys-map.h:285 [inline]
drm_fb_memcpy+0x459/0x620 drivers/gpu/drm/drm_format_helper.c:442
cirrus_primary_plane_helper_atomic_update+0xb1d/0xfe0 drivers/gpu/drm/tiny/cirrus-qemu.c:358
drm_atomic_helper_commit_planes+0x497/0xf10 drivers/gpu/drm/drm_atomic_helper.c:3038
drm_atomic_helper_commit_tail+0x7f/0x130 drivers/gpu/drm/drm_atomic_helper.c:1989
commit_tail+0x338/0x430 drivers/gpu/drm/drm_atomic_helper.c:2074
drm_atomic_helper_commit+0x303/0x380 drivers/gpu/drm/drm_atomic_helper.c:2312
drm_atomic_commit+0x230/0x300 drivers/gpu/drm/drm_atomic.c:1789
drm_client_modeset_commit_atomic+0x6a6/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1104
drm_client_modeset_commit_locked+0x14d/0x580 drivers/gpu/drm/drm_client_modeset.c:1207
drm_client_modeset_commit+0x4f/0x80 drivers/gpu/drm/drm_client_modeset.c:1233
__drm_fb_helper_restore_fbdev_mode_unlocked.part.0+0x137/0x160 drivers/gpu/drm/drm_fb_helper.c:138
__drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:126 [inline]
drm_fb_helper_restore_fbdev_mode_unlocked+0x93/0xc0 drivers/gpu/drm/drm_fb_helper.c:169
drm_fbdev_client_restore+0x1b/0x30 drivers/gpu/drm/clients/drm_fbdev_client.c:45
drm_client_dev_restore+0x205/0x2a0 drivers/gpu/drm/drm_client_event.c:118
drm_lastclose drivers/gpu/drm/drm_file.c:408 [inline]
drm_release+0x2c6/0x360 drivers/gpu/drm/drm_file.c:441
__fput+0x3ff/0xb50 fs/file_table.c:512
task_work_run+0x150/0x240 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
exit_to_user_mode_loop+0x1d8/0x6f0 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
__do_fast_syscall_32+0x701/0x970 arch/x86/entry/syscall_32.c:310
do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f15fec
Code: Unable to access opcode bytes at 0xf7f15fc2.
RSP: 002b:00000000ffd3840c EFLAGS: 00000202
ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 000000000000001e
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
Modules linked in:
CR2: ffffc90007196000
---[ end trace 0000000000000000 ]---
RIP: 0010:rep_movs arch/x86/lib/iomem.c:13 [inline]
RIP: 0010:string_memcpy_toio arch/x86/lib/iomem.c:64 [inline]
RIP: 0010:memcpy_toio+0x87/0xe0 arch/x86/lib/iomem.c:110
Code: b8 fc 49 89 dd 31 ff 41 83 e5 02 4c 89 ee e8 f0 28 b8 fc 4d 85 ed 75 33 e8 46 2e b8 fc 48 89 e9 48 89 df 4c 89 e6 48 c1 e9 02 <f3> a5 40 f6 c5 02 74 02 66 a5 40 f6 c5 01 74 01 a4 e8 23 2e b8 fc
RSP: 0018:ffffc9000782f5c0 EFLAGS: 00010206
RAX: 0000000000000000 RBX: ffffc90007195d20 RCX: 00000000000000d8
RDX: ffff88802232ca80 RSI: ffffc90004051f60 RDI: ffffc90007196000
RBP: 0000000000000640 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 000000000000001e R12: ffffc90004051c80
R13: 0000000000000000 R14: ffffc90007195d20 R15: 0000000000000640
FS: 0000000000000000(0000) GS:ffff888096bdf000(0063) knlGS:0000000056b41480
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f7f16000 CR3: 0000000070295000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
0: b8 fc 49 89 dd mov $0xdd8949fc,%eax
5: 31 ff xor %edi,%edi
7: 41 83 e5 02 and $0x2,%r13d
b: 4c 89 ee mov %r13,%rsi
e: e8 f0 28 b8 fc call 0xfcb82903
13: 4d 85 ed test %r13,%r13
16: 75 33 jne 0x4b
18: e8 46 2e b8 fc call 0xfcb82e63
1d: 48 89 e9 mov %rbp,%rcx
20: 48 89 df mov %rbx,%rdi
23: 4c 89 e6 mov %r12,%rsi
26: 48 c1 e9 02 shr $0x2,%rcx
* 2a: f3 a5 rep movsl %ds:(%rsi),%es:(%rdi) <-- trapping instruction
2c: 40 f6 c5 02 test $0x2,%bpl
30: 74 02 je 0x34
32: 66 a5 movsw %ds:(%rsi),%es:(%rdi)
34: 40 f6 c5 01 test $0x1,%bpl
38: 74 01 je 0x3b
3a: a4 movsb %ds:(%rsi),%es:(%rdi)
3b: e8 23 2e b8 fc call 0xfcb82e63
---
This report 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 syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
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