8<--- cut here --- Unable to handle kernel paging request at virtual address fee00140 when write [fee00140] *pgd=80000080007003, *pmd=00000000 Internal error: Oops: a06 [#1] SMP ARM Modules linked in: CPU: 0 UID: 0 PID: 21445 Comm: syz.6.1746 Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: ARM-Versatile Express PC is at __raw_writeb arch/arm/include/asm/io.h:99 [inline] PC is at parport_attach drivers/comedi/drivers/comedi_parport.c:291 [inline] PC is at parport_attach+0x184/0x1e0 drivers/comedi/drivers/comedi_parport.c:224 LR is at parport_attach drivers/comedi/drivers/comedi_parport.c:291 [inline] LR is at parport_attach+0x174/0x1e0 drivers/comedi/drivers/comedi_parport.c:224 pc : [<81494524>] lr : [<81494514>] psr: 60000013 sp : dfd3dd30 ip : dfd3dd30 fp : dfd3dd54 r10: 82d30dfc r9 : 00000003 r8 : 8301a180 r7 : dfd3dd90 r6 : 8301a180 r5 : 00000000 r4 : 00000000 r3 : fee00140 r2 : 81e2dee8 r1 : 00000001 r0 : 81494184 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 841d29c0 DAC: fffffffd Register r0 information: non-slab/vmalloc memory Register r1 information: non-paged memory Register r2 information: non-slab/vmalloc memory Register r3 information: 0-page vmalloc region starting at 0xfee00000 allocated at pci_reserve_io+0x0/0x38 arch/arm/mm/mmu.c:1048 Register r4 information: NULL pointer Register r5 information: NULL pointer Register r6 information: slab kmalloc-192 start 8301a180 pointer offset 0 size 192 Register r7 information: 2-page vmalloc region starting at 0xdfd3c000 allocated at kernel_clone+0xc4/0x43c kernel/fork.c:2748 Register r8 information: slab kmalloc-192 start 8301a180 pointer offset 0 size 192 Register r9 information: non-paged memory Register r10 information: non-slab/vmalloc memory Register r11 information: 2-page vmalloc region starting at 0xdfd3c000 allocated at kernel_clone+0xc4/0x43c kernel/fork.c:2748 Register r12 information: 2-page vmalloc region starting at 0xdfd3c000 allocated at kernel_clone+0xc4/0x43c kernel/fork.c:2748 Process syz.6.1746 (pid: 21445, stack limit = 0xdfd3c000) Stack: (0xdfd3dd30 to 0xdfd3e000) dd20: ffffffff 00000004 82bd8ea0 82bd8ea0 dd40: 81e2e3a8 00000000 dfd3dd8c dfd3dd58 814900a0 814943ac 40946400 00000000 dd60: dfd3dd7c 200003c0 8301a180 b5403587 40946400 00000002 00000003 84083100 dd80: dfd3de4c dfd3dd90 8148b8a4 8148ffa4 656d6f63 705f6964 6f707261 00007472 dda0: 00000000 00000140 00000000 0001000c 0000dddc 00000000 00010000 00007fff ddc0: 00000006 00000007 0000c72c 02000004 0000000f 0000c000 00000008 000004ce dde0: 00008e99 00000001 000000ed 00000006 00000008 00000004 00000000 0000000a de00: 00000009 00000ffd 00000009 000000af 00000002 00000283 00008001 00000009 de20: 00000000 73d3a456 00000000 85befb00 8301a180 200003c0 40946400 00000002 de40: dfd3df14 dfd3de50 8148cbcc 8148b7e4 00000000 73d3a456 00000000 00000000 de60: 8254980c dfd3dea4 0000005f 83fdfa28 00000064 8301a1b0 dfd3dee4 dfd3de88 de80: 808062d4 807fc98c 00000064 00000001 00000000 dfd3dea4 86943110 83439aa0 dea0: 00006400 0000000b dfd3de98 00000000 00000000 73d3a456 00000000 85befb00 dec0: 40946400 200003c0 200003c0 85befb00 00000003 84083100 dfd3def4 dfd3dee8 dee0: 80806408 73d3a456 dfd3df14 00000000 85befb01 40946400 200003c0 85befb00 df00: 00000003 84083100 dfd3dfa4 dfd3df18 805baf7c 8148c884 ecac8b10 84083100 df20: dfd3df3c dfd3df30 81b5a5e0 81b5a4ac dfd3df54 dfd3df40 8025a7a8 8028e490 df40: dfd3dfb0 40000000 dfd3df84 dfd3df58 80220bdc 8025a764 00000000 82a1eb0c df60: dfd3dfb0 0013ea70 ecac8b10 80220b30 00000000 73d3a456 dfd3dfac 00000000 df80: 00000000 00356310 00000036 8020029c 84083100 00000036 00000000 dfd3dfa8 dfa0: 80200060 805bad44 00000000 00000000 00000003 40946400 200003c0 00000000 dfc0: 00000000 00000000 00356310 00000036 003562d8 00000000 00000001 76fd40dc dfe0: 76fd3e88 76fd3e78 00018ebc 001308d0 60000010 00000003 00000000 00000000 Call trace: [<814943a0>] (parport_attach) from [<814900a0>] (comedi_device_attach+0x108/0x244 drivers/comedi/drivers.c:1101) r6:00000000 r5:81e2e3a8 r4:82bd8ea0 [<8148ff98>] (comedi_device_attach) from [<8148b8a4>] (do_devconfig_ioctl+0xcc/0x218 drivers/comedi/comedi_fops.c:930) r10:84083100 r9:00000003 r8:00000002 r7:40946400 r6:b5403587 r5:8301a180 r4:200003c0 [<8148b7d8>] (do_devconfig_ioctl) from [<8148cbcc>] (comedi_unlocked_ioctl+0x354/0x1db8 drivers/comedi/comedi_fops.c:2302) r8:00000002 r7:40946400 r6:200003c0 r5:8301a180 r4:85befb00 [<8148c878>] (comedi_unlocked_ioctl) from [<805baf7c>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<8148c878>] (comedi_unlocked_ioctl) from [<805baf7c>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<8148c878>] (comedi_unlocked_ioctl) from [<805baf7c>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<8148c878>] (comedi_unlocked_ioctl) from [<805baf7c>] (sys_ioctl+0x244/0xb5c fs/ioctl.c:583) r10:84083100 r9:00000003 r8:85befb00 r7:200003c0 r6:40946400 r5:85befb01 r4:00000000 [<805bad38>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfd3dfa8 to 0xdfd3dff0) dfa0: 00000000 00000000 00000003 40946400 200003c0 00000000 dfc0: 00000000 00000000 00356310 00000036 003562d8 00000000 00000001 76fd40dc dfe0: 76fd3e88 76fd3e78 00018ebc 001308d0 r10:00000036 r9:84083100 r8:8020029c r7:00000036 r6:00356310 r5:00000000 r4:00000000 Code: e5963064 e3a04000 e7f33053 e2433612 (e5c34000) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: e5963064 ldr r3, [r6, #100] @ 0x64 4: e3a04000 mov r4, #0 8: e7f33053 ubfx r3, r3, #0, #20 c: e2433612 sub r3, r3, #18874368 @ 0x1200000 * 10: e5c34000 strb r4, [r3] <-- trapping instruction