Hello, When using Healer to fuzz the latest Linux kernel, the following crash was triggered. HEAD commit: 42d43c92fc57 Merge branch 'for-linus' git tree: upstream console output: https://drive.google.com/file/d/1TXbZJ5Reefwpvr_wk3N1rGVKIMnF6fbP/view?usp=sharing kernel config: https://drive.google.com/file/d/15vWoQRbJuuMu4ovWhUm1h4SrHyNwK8im/view?usp=sharing Sorry, I don't have a reproducer for this crash, hope the symbolized report can help. If you fix this issue, please add the following tag to the commit: Reported-by: Hao Sun <sunhao.th@xxxxxxxxx> BUG: unable to handle page fault for address: ffffc900085e8070 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 10c00067 P4D 10c00067 PUD 10dbc067 PMD 1c94d067 PTE 0 Oops: 0002 [#1] PREEMPT SMP KASAN CPU: 3 PID: 33 Comm: kworker/3:0 Not tainted 5.15.0-rc3+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Workqueue: events drm_fb_helper_damage_work RIP: 0010:rep_movs arch/x86/lib/iomem.c:12 [inline] RIP: 0010:memcpy_toio+0x83/0xe0 arch/x86/lib/iomem.c:57 Code: 7a fd 49 89 dd 31 ff 41 83 e5 02 4c 89 ee e8 44 73 7a fd 4d 85 ed 75 2e e8 ba 71 7a fd 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 5b 5d 41 5c 41 RSP: 0018:ffffc90000887be0 EFLAGS: 00010212 RAX: 0000000000000000 RBX: ffffc900085e8070 RCX: 000000000000094c RDX: 0000000000000000 RSI: ffffc90006599070 RDI: ffffc900085e8070 RBP: 0000000000002530 R08: ffffffff83fbd9c6 R09: 0000000000000000 R10: 0000000000000007 R11: fffff52000110f56 R12: ffffc90006599070 R13: 0000000000000000 R14: ffff888019db0140 R15: ffffc90006599070 FS: 0000000000000000(0000) GS:ffff888135d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffc900085e8070 CR3: 000000001d3fd000 CR4: 0000000000350ee0 Call Trace: dma_buf_map_memcpy_to ./include/linux/dma-buf-map.h:245 [inline] drm_fb_helper_damage_blit_real drivers/gpu/drm/drm_fb_helper.c:388 [inline] drm_fb_helper_damage_blit drivers/gpu/drm/drm_fb_helper.c:419 [inline] drm_fb_helper_damage_work+0x76d/0xb00 drivers/gpu/drm/drm_fb_helper.c:450 process_one_work+0x9df/0x16d0 kernel/workqueue.c:2297 worker_thread+0x90/0xed0 kernel/workqueue.c:2444 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Modules linked in: Dumping ftrace buffer: (ftrace buffer empty) CR2: ffffc900085e8070 ---[ end trace 000e7483a76d6bd7 ]--- RIP: 0010:rep_movs arch/x86/lib/iomem.c:12 [inline] RIP: 0010:memcpy_toio+0x83/0xe0 arch/x86/lib/iomem.c:57 Code: 7a fd 49 89 dd 31 ff 41 83 e5 02 4c 89 ee e8 44 73 7a fd 4d 85 ed 75 2e e8 ba 71 7a fd 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 5b 5d 41 5c 41 RSP: 0018:ffffc90000887be0 EFLAGS: 00010212 RAX: 0000000000000000 RBX: ffffc900085e8070 RCX: 000000000000094c RDX: 0000000000000000 RSI: ffffc90006599070 RDI: ffffc900085e8070 RBP: 0000000000002530 R08: ffffffff83fbd9c6 R09: 0000000000000000 R10: 0000000000000007 R11: fffff52000110f56 R12: ffffc90006599070 R13: 0000000000000000 R14: ffff888019db0140 R15: ffffc90006599070 FS: 0000000000000000(0000) GS:ffff888135d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffc900085e8070 CR3: 000000001d3fd000 CR4: 0000000000350ee0 ---------------- Code disassembly (best guess): 0: 7a fd jp 0xffffffff 2: 49 89 dd mov %rbx,%r13 5: 31 ff xor %edi,%edi 7: 41 83 e5 02 and $0x2,%r13d b: 4c 89 ee mov %r13,%rsi e: e8 44 73 7a fd callq 0xfd7a7357 13: 4d 85 ed test %r13,%r13 16: 75 2e jne 0x46 18: e8 ba 71 7a fd callq 0xfd7a71d7 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: 5b pop %rbx 3c: 5d pop %rbp 3d: 41 5c pop %r12 3f: 41 rex.B