8<--- cut here --- Unable to handle kernel paging request at virtual address fee00078 when write [fee00078] *pgd=80000080007003, *pmd=00000000 Internal error: Oops: a06 [#1] SMP ARM Modules linked in: CPU: 0 UID: 0 PID: 6838 Comm: syz.4.481 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: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 : [<8145a1ec>] lr : [<8145a1dc>] psr: 60000013 sp : e03fdd30 ip : e03fdd30 fp : e03fdd54 r10: 82d2cdd4 r9 : 00000003 r8 : 8301b240 r7 : e03fdd90 r6 : 8301b240 r5 : 00000000 r4 : 00000000 r3 : fee00078 r2 : 81e277a8 r1 : 00000001 r0 : 81459e4c Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 85de1dc0 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 8301b240 pointer offset 0 size 192 Register r7 information: 2-page vmalloc region starting at 0xe03fc000 allocated at kernel_clone+0xbc/0x43c kernel/fork.c:2721 Register r8 information: slab kmalloc-192 start 8301b240 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 0xe03fc000 allocated at kernel_clone+0xbc/0x43c kernel/fork.c:2721 Register r12 information: 2-page vmalloc region starting at 0xe03fc000 allocated at kernel_clone+0xbc/0x43c kernel/fork.c:2721 Process syz.4.481 (pid: 6838, stack limit = 0xe03fc000) Stack: (0xe03fdd30 to 0xe03fe000) dd20: ffffffff 00000004 00000000 82bd2c7c dd40: 81e27c68 00000000 e03fdd8c e03fdd58 81455d4c 8145a074 40946400 00000000 dd60: e03fdd7c 20000600 8301b240 b5403587 40946400 00000003 00000003 833f2580 dd80: e03fde4c e03fdd90 81451558 81455c50 656d6f63 705f6964 6f707261 00007472 dda0: 00000000 00000078 00000000 00000000 0000000c 00000008 00000006 00100002 ddc0: 00000007 00000005 00000100 00000004 00000001 00000001 00020003 00000000 dde0: 00000101 00000083 00000007 00000003 00001b18 00000016 00000004 00000000 de00: ffffffff 0000000b 00000004 0000003b 0000000c 10000006 00000664 fffffff8 de20: 00000000 04bc9309 00000000 838ac200 8301b240 20000600 40946400 00000003 de40: e03fdf14 e03fde50 8145287c 81451490 00000000 04bc9309 00000000 00000000 de60: 82531804 e03fdea4 0000005f 84198990 00000064 8301b270 e03fdee4 e03fde88 de80: 807ea514 807e0828 00000064 00000001 00000000 e03fdea4 8335ae50 834ea550 dea0: 00006400 0000000b e03fde98 00000000 00000000 04bc9309 00000000 838ac200 dec0: 40946400 20000600 20000600 838ac200 00000003 833f2580 e03fdef4 e03fdee8 dee0: 807ea648 04bc9309 e03fdf14 00000000 838ac201 40946400 20000600 838ac200 df00: 00000003 833f2580 e03fdfa4 e03fdf18 805a1e5c 81452534 ecac8b10 833f2580 df20: e03fdf3c e03fdf30 81b18b14 81b189e0 e03fdf54 e03fdf40 8025a6bc 8028e2a4 df40: e03fdfb0 40000000 e03fdf84 e03fdf58 80220be0 8025a678 00000000 82a1c63c df60: e03fdfb0 0013e9b0 ecac8b10 80220b34 00000000 04bc9309 e03fdfac 00000000 df80: 00000000 00346310 00000036 8020029c 833f2580 00000036 00000000 e03fdfa8 dfa0: 80200060 805a1c24 00000000 00000000 00000003 40946400 20000600 00000000 dfc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76fa70dc dfe0: 76fa6e88 76fa6e78 00018ebc 00130810 60000010 00000003 00000000 00000000 Call trace: [<8145a068>] (parport_attach) from [<81455d4c>] (comedi_device_attach+0x108/0x244 drivers/comedi/drivers.c:1101) r6:00000000 r5:81e27c68 r4:82bd2c7c [<81455c44>] (comedi_device_attach) from [<81451558>] (do_devconfig_ioctl+0xd4/0x21c drivers/comedi/comedi_fops.c:930) r10:833f2580 r9:00000003 r8:00000003 r7:40946400 r6:b5403587 r5:8301b240 r4:20000600 [<81451484>] (do_devconfig_ioctl) from [<8145287c>] (comedi_unlocked_ioctl+0x354/0x1db8 drivers/comedi/comedi_fops.c:2302) r8:00000003 r7:40946400 r6:20000600 r5:8301b240 r4:838ac200 [<81452528>] (comedi_unlocked_ioctl) from [<805a1e5c>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<81452528>] (comedi_unlocked_ioctl) from [<805a1e5c>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<81452528>] (comedi_unlocked_ioctl) from [<805a1e5c>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<81452528>] (comedi_unlocked_ioctl) from [<805a1e5c>] (sys_ioctl+0x244/0xb5c fs/ioctl.c:583) r10:833f2580 r9:00000003 r8:838ac200 r7:20000600 r6:40946400 r5:838ac201 r4:00000000 [<805a1c18>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xe03fdfa8 to 0xe03fdff0) dfa0: 00000000 00000000 00000003 40946400 20000600 00000000 dfc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76fa70dc dfe0: 76fa6e88 76fa6e78 00018ebc 00130810 r10:00000036 r9:833f2580 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