Hello,

syzbot found the following issue on:

HEAD commit: e66435936756 mm: fix mismerge of folio page flag manipulat.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=14c79e0eb00000 kernel config: https://syzkaller.appspot.com/x/.config?x=ca1c2027dfeaf335 dashboard link: https://syzkaller.appspot.com/bug?extid=f01248cf57e6929868e4 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, 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+f01248cf57e6929868e4@syzkaller.appspotmail.com

R13: 00007ffe6190e50f R14: 00007f51be874300 R15: 0000000000022000 ================================================================== BUG: KASAN: out-of-bounds in memset include/linux/fortify-string.h:175 [inline] BUG: KASAN: out-of-bounds in virtio_gpu_cmd_transfer_to_host_2d+0x160/0x4a0 drivers/gpu/drm/virtio/virtgpu_vq.c:618 Write of size 56 at addr fffffffffffffff4 by task syz-executor.1/13670

CPU: 2 PID: 13670 Comm: syz-executor.1 Not tainted 5.15.0-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0xf/0x2d6 mm/kasan/report.c:256 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189 memset+0x20/0x40 mm/kasan/shadow.c:44 memset include/linux/fortify-string.h:175 [inline] virtio_gpu_cmd_transfer_to_host_2d+0x160/0x4a0 drivers/gpu/drm/virtio/virtgpu_vq.c:618 virtio_gpu_update_dumb_bo drivers/gpu/drm/virtio/virtgpu_plane.c:128 [inline] virtio_gpu_primary_plane_update+0xfcb/0x1650 drivers/gpu/drm/virtio/virtgpu_plane.c:199 drm_atomic_helper_commit_planes+0x332/0xb60 drivers/gpu/drm/drm_atomic_helper.c:2552 drm_atomic_helper_commit_tail+0x62/0xf0 drivers/gpu/drm/drm_atomic_helper.c:1582 commit_tail+0x32d/0x420 drivers/gpu/drm/drm_atomic_helper.c:1667 drm_atomic_helper_commit drivers/gpu/drm/drm_atomic_helper.c:1884 [inline] drm_atomic_helper_commit+0x2eb/0x370 drivers/gpu/drm/drm_atomic_helper.c:1817 drm_atomic_commit+0xd8/0x110 drivers/gpu/drm/drm_atomic.c:1412 drm_client_modeset_commit_atomic+0x685/0x7c0 drivers/gpu/drm/drm_client_modeset.c:1043 drm_client_modeset_commit_locked+0x145/0x580 drivers/gpu/drm/drm_client_modeset.c:1146 drm_client_modeset_commit+0x4d/0x80 drivers/gpu/drm/drm_client_modeset.c:1172 __drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:252 [inline] __drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:231 [inline] drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:279 [inline] drm_fb_helper_lastclose drivers/gpu/drm/drm_fb_helper.c:1997 [inline] drm_fbdev_client_restore+0xe3/0x1a0 drivers/gpu/drm/drm_fb_helper.c:2397 drm_client_dev_restore+0x184/0x290 drivers/gpu/drm/drm_client.c:226 drm_lastclose drivers/gpu/drm/drm_file.c:467 [inline] drm_release+0x441/0x530 drivers/gpu/drm/drm_file.c:498 __fput+0x286/0x9f0 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f51c12b1a04 Code: 84 00 00 00 00 00 44 89 54 24 0c e8 96 f9 ff ff 44 8b 54 24 0c 44 89 e2 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 34 44 89 c7 89 44 24 0c e8 c8 f9 ff ff 8b 44 RSP: 002b:00007f51be873cc0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffea RBX: 6666666666666667 RCX: 00007f51c12b1a04 RDX: 000000000000ff00 RSI: 00007f51be873d60 RDI: 00000000ffffff9c RBP: 00007f51be873d60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 000000000000ff00 R13: 00007ffe6190e50f R14: 00007f51be874300 R15: 0000000000022000

Memory state around the buggy address: fffffffffffffe80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffffffffffff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

ffffffffffffff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

general protection fault, maybe for address 0xffffc9000422f80c: 0000 [#1] PREEMPT SMP KASAN CPU: 2 PID: 13670 Comm: syz-executor.1 Not tainted 5.15.0-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 RIP: 0010:memcpy_erms+0x6/0x10 arch/x86/lib/memcpy_64.S:55 Code: cc cc cc cc eb 1e 0f 1f 00 48 89 f8 48 89 d1 48 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 c3 66 0f 1f 44 00 00 48 89 f8 48 89 d1 <f3> a4 c3 0f 1f 80 00 00 00 00 48 89 f8 48 83 fa 20 72 7e 40 38 fe RSP: 0018:ffffc9000422f800 EFLAGS: 00010086 RAX: ffffc9000422f80c RBX: 0000000000000000 RCX: 0000000000000010 RDX: 0000000000000010 RSI: dffffc0000000000 RDI: ffffc9000422f80c RBP: fffffffffffffff4 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff83f599a3 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000080 R14: ffffffff84620a60 R15: 0000000000000000 FS: 00007f51be874700(0000) GS:ffff88802cc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f51be873f78 CR3: 0000000077e04000 CR4: 0000000000150ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: print_memory_metadata+0x5a/0xdf mm/kasan/report.c:322 __kasan_report mm/kasan/report.c:444 [inline] kasan_report.cold+0x99/0xdf mm/kasan/report.c:459 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189 memset+0x20/0x40 mm/kasan/shadow.c:44 memset include/linux/fortify-string.h:175 [inline] virtio_gpu_cmd_transfer_to_host_2d+0x160/0x4a0 drivers/gpu/drm/virtio/virtgpu_vq.c:618 virtio_gpu_update_dumb_bo drivers/gpu/drm/virtio/virtgpu_plane.c:128 [inline] virtio_gpu_primary_plane_update+0xfcb/0x1650 drivers/gpu/drm/virtio/virtgpu_plane.c:199 drm_atomic_helper_commit_planes+0x332/0xb60 drivers/gpu/drm/drm_atomic_helper.c:2552 drm_atomic_helper_commit_tail+0x62/0xf0 drivers/gpu/drm/drm_atomic_helper.c:1582 commit_tail+0x32d/0x420 drivers/gpu/drm/drm_atomic_helper.c:1667 drm_atomic_helper_commit drivers/gpu/drm/drm_atomic_helper.c:1884 [inline] drm_atomic_helper_commit+0x2eb/0x370 drivers/gpu/drm/drm_atomic_helper.c:1817 drm_atomic_commit+0xd8/0x110 drivers/gpu/drm/drm_atomic.c:1412 drm_client_modeset_commit_atomic+0x685/0x7c0 drivers/gpu/drm/drm_client_modeset.c:1043 drm_client_modeset_commit_locked+0x145/0x580 drivers/gpu/drm/drm_client_modeset.c:1146 drm_client_modeset_commit+0x4d/0x80 drivers/gpu/drm/drm_client_modeset.c:1172 __drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:252 [inline] __drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:231 [inline] drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:279 [inline] drm_fb_helper_lastclose drivers/gpu/drm/drm_fb_helper.c:1997 [inline] drm_fbdev_client_restore+0xe3/0x1a0 drivers/gpu/drm/drm_fb_helper.c:2397 drm_client_dev_restore+0x184/0x290 drivers/gpu/drm/drm_client.c:226 drm_lastclose drivers/gpu/drm/drm_file.c:467 [inline] drm_release+0x441/0x530 drivers/gpu/drm/drm_file.c:498 __fput+0x286/0x9f0 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f51c12b1a04 Code: 84 00 00 00 00 00 44 89 54 24 0c e8 96 f9 ff ff 44 8b 54 24 0c 44 89 e2 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 34 44 89 c7 89 44 24 0c e8 c8 f9 ff ff 8b 44 RSP: 002b:00007f51be873cc0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffea RBX: 6666666666666667 RCX: 00007f51c12b1a04 RDX: 000000000000ff00 RSI: 00007f51be873d60 RDI: 00000000ffffff9c RBP: 00007f51be873d60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 000000000000ff00 R13: 00007ffe6190e50f R14: 00007f51be874300 R15: 0000000000022000 Modules linked in: ---[ end trace f65df7177f1d34a7 ]--- RIP: 0010:memcpy_erms+0x6/0x10 arch/x86/lib/memcpy_64.S:55 Code: cc cc cc cc eb 1e 0f 1f 00 48 89 f8 48 89 d1 48 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 c3 66 0f 1f 44 00 00 48 89 f8 48 89 d1 <f3> a4 c3 0f 1f 80 00 00 00 00 48 89 f8 48 83 fa 20 72 7e 40 38 fe RSP: 0018:ffffc9000422f800 EFLAGS: 00010086 RAX: ffffc9000422f80c RBX: 0000000000000000 RCX: 0000000000000010 RDX: 0000000000000010 RSI: dffffc0000000000 RDI: ffffc9000422f80c RBP: fffffffffffffff4 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff83f599a3 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000080 R14: ffffffff84620a60 R15: 0000000000000000 FS: 00007f51be874700(0000) GS:ffff88802cc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f51be873f78 CR3: 0000000077e04000 CR4: 0000000000150ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: cc int3 1: cc int3 2: cc int3 3: cc int3 4: eb 1e jmp 0x24 6: 0f 1f 00 nopl (%rax) 9: 48 89 f8 mov %rdi,%rax c: 48 89 d1 mov %rdx,%rcx f: 48 c1 e9 03 shr $0x3,%rcx 13: 83 e2 07 and $0x7,%edx 16: f3 48 a5 rep movsq %ds:(%rsi),%es:(%rdi) 19: 89 d1 mov %edx,%ecx 1b: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) 1d: c3 retq 1e: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 24: 48 89 f8 mov %rdi,%rax 27: 48 89 d1 mov %rdx,%rcx * 2a: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction 2c: c3 retq 2d: 0f 1f 80 00 00 00 00 nopl 0x0(%rax) 34: 48 89 f8 mov %rdi,%rax 37: 48 83 fa 20 cmp $0x20,%rdx 3b: 72 7e jb 0xbb 3d: 40 38 fe cmp %dil,%sil

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