8<--- cut here --- Unable to handle kernel paging request at virtual address fee00400 when write [fee00400] *pgd=80000080007003, *pmd=00000000 Internal error: Oops: a06 [#1] SMP ARM Modules linked in: CPU: 0 UID: 0 PID: 4800 Comm: syz.0.291 Not tainted syzkaller #0 PREEMPT Hardware name: ARM-Versatile Express PC is at __raw_writeb arch/arm/include/asm/io.h:88 [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 : [<81459afc>] lr : [<81459aec>] psr: 60000013 sp : dfbadd30 ip : dfbadd30 fp : dfbadd54 r10: 82d2cdc4 r9 : 00000003 r8 : 8334d840 r7 : dfbadd90 r6 : 8334d840 r5 : 00000000 r4 : 00000000 r3 : fee00400 r2 : 81e277a8 r1 : 00000001 r0 : 8145975c Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 862560c0 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 8334d840 pointer offset 0 size 192 Register r7 information: 2-page vmalloc region starting at 0xdfbac000 allocated at kernel_clone+0xbc/0x43c kernel/fork.c:2721 Register r8 information: slab kmalloc-192 start 8334d840 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 0xdfbac000 allocated at kernel_clone+0xbc/0x43c kernel/fork.c:2721 Register r12 information: 2-page vmalloc region starting at 0xdfbac000 allocated at kernel_clone+0xbc/0x43c kernel/fork.c:2721 Process syz.0.291 (pid: 4800, stack limit = 0xdfbac000) Stack: (0xdfbadd30 to 0xdfbae000) dd20: 824bcfa8 8334d840 00000000 82bd2c7c dd40: 81e27c68 00000000 dfbadd8c dfbadd58 81455660 81459984 40946400 00000000 dd60: dfbadd7c 20000140 8334d840 b5403587 40946400 00000001 00000003 85020c80 dd80: dfbade4c dfbadd90 81450e6c 81455564 656d6f63 705f6964 6f707261 00007472 dda0: 00000000 00000400 00000002 7fffffff 000084e1 0000002f 00002006 00000006 ddc0: 00000008 000a0ffa 00000000 00000007 00000002 00001003 01000004 0000000f dde0: 00010000 ffffffa8 7ffbfffd 000001ff 0000ecd0 00000010 0003fffe 00000008 de00: 00000007 0000746f 00000004 00000005 00000408 00000004 00000000 00007ffd de20: 00000000 7f6ed03a 00000000 838d8c80 8334d840 20000140 40946400 00000001 de40: dfbadf14 dfbade50 81452190 81450da4 00000000 7f6ed03a 00000000 00000000 de60: 82531804 dfbadea4 0000005f 84567dd8 00000064 8334d870 dfbadee4 dfbade88 de80: 807ea1fc 807e0510 00000064 00000001 00000000 dfbadea4 830ea190 834de330 dea0: 00006400 0000000b dfbade98 00000000 00000000 7f6ed03a 00000000 838d8c80 dec0: 40946400 20000140 20000140 838d8c80 00000003 85020c80 dfbadef4 dfbadee8 dee0: 807ea330 7f6ed03a dfbadf14 00000000 838d8c80 40946400 20000140 838d8c80 df00: 00000003 85020c80 dfbadfa4 dfbadf18 805a1b84 81451e48 ecac8b10 85020c80 df20: dfbadf3c dfbadf30 81b17c54 81b17b20 dfbadf54 dfbadf40 8025a6bc 8028e2a4 df40: dfbadfb0 40000000 dfbadf84 dfbadf58 80220be0 8025a678 00000000 82a1c63c df60: dfbadfb0 0013e9b0 ecac8b10 80220b34 00000000 7f6ed03a dfbadfac 00000000 df80: 00000000 00346310 00000036 8020029c 85020c80 00000036 00000000 dfbadfa8 dfa0: 80200060 805a194c 00000000 00000000 00000003 40946400 20000140 00000000 dfc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76fc00dc dfe0: 76fbfe88 76fbfe78 00018ebc 00130810 60000010 00000003 00000000 00000000 Call trace: [<81459978>] (parport_attach) from [<81455660>] (comedi_device_attach+0x108/0x244 drivers/comedi/drivers.c:1101) r6:00000000 r5:81e27c68 r4:82bd2c7c [<81455558>] (comedi_device_attach) from [<81450e6c>] (do_devconfig_ioctl+0xd4/0x21c drivers/comedi/comedi_fops.c:930) r10:85020c80 r9:00000003 r8:00000001 r7:40946400 r6:b5403587 r5:8334d840 r4:20000140 [<81450d98>] (do_devconfig_ioctl) from [<81452190>] (comedi_unlocked_ioctl+0x354/0x1db8 drivers/comedi/comedi_fops.c:2302) r8:00000001 r7:40946400 r6:20000140 r5:8334d840 r4:838d8c80 [<81451e3c>] (comedi_unlocked_ioctl) from [<805a1b84>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<81451e3c>] (comedi_unlocked_ioctl) from [<805a1b84>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<81451e3c>] (comedi_unlocked_ioctl) from [<805a1b84>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<81451e3c>] (comedi_unlocked_ioctl) from [<805a1b84>] (sys_ioctl+0x244/0xb5c fs/ioctl.c:583) r10:85020c80 r9:00000003 r8:838d8c80 r7:20000140 r6:40946400 r5:838d8c80 r4:00000000 [<805a1940>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfbadfa8 to 0xdfbadff0) dfa0: 00000000 00000000 00000003 40946400 20000140 00000000 dfc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76fc00dc dfe0: 76fbfe88 76fbfe78 00018ebc 00130810 r10:00000036 r9:85020c80 r8:8020029c r7:00000036 r6:00346310 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