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: 1 UID: 0 PID: 4700 Comm: syz.1.251 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 : [<8144d544>] lr : [<8144d534>] psr: 60000013 sp : dfb95d30 ip : dfb95d30 fp : dfb95d54 r10: 82d2bd44 r9 : 00000003 r8 : 8334b6c0 r7 : dfb95d90 r6 : 8334b6c0 r5 : 00000000 r4 : 00000000 r3 : fee00400 r2 : 81e274c8 r1 : 00000001 r0 : 8144d1a4 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 86262540 DAC: 00000000 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 8334b6c0 pointer offset 0 size 192 Register r7 information: 2-page vmalloc region starting at 0xdfb94000 allocated at kernel_clone+0xbc/0x438 kernel/fork.c:2723 Register r8 information: slab kmalloc-192 start 8334b6c0 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 0xdfb94000 allocated at kernel_clone+0xbc/0x438 kernel/fork.c:2723 Register r12 information: 2-page vmalloc region starting at 0xdfb94000 allocated at kernel_clone+0xbc/0x438 kernel/fork.c:2723 Process syz.1.251 (pid: 4700, stack limit = 0xdfb94000) Stack: (0xdfb95d30 to 0xdfb96000) 5d20: 824ba458 8334b6c0 00000000 82bd26a0 5d40: 81e27988 00000000 dfb95d8c dfb95d58 814490a4 8144d3cc 40946400 00000000 5d60: dfb95d7c 20000140 8334b6c0 b5403587 40946400 00000001 00000005 83fa1880 5d80: dfb95e4c dfb95d90 814448b0 81448fa8 656d6f63 705f6964 6f707261 00007472 5da0: 00000000 00000400 00000002 7fffffff 000084e1 0000002f 00002006 00000006 5dc0: 00000008 000a0ffa 00000000 00000007 00000002 00001003 01000004 0000000f 5de0: 00010000 ffffffa8 7ffbfffd 000001ff 0000ecd0 00000010 0003fffe 00000008 5e00: 00000007 0000746f 00000004 00000005 00000408 00000004 00000000 00007ffd 5e20: 00000000 c5ac77bf 00000000 838da380 8334b6c0 20000140 40946400 00000001 5e40: dfb95f14 dfb95e50 81445bd4 814447e8 00000000 c5ac77bf 00000000 00000000 5e60: 8252e804 dfb95ea4 0000005f 844010f0 00000064 8334b6f0 dfb95ee4 dfb95e88 5e80: 807ded8c 807d50bc 00000064 00000001 00000000 dfb95ea4 8383ed90 834e6ee0 5ea0: 00006400 0000000b dfb95e98 00000000 00000000 c5ac77bf 00000000 838da380 5ec0: 40946400 20000140 20000140 838da380 00000005 83fa1880 dfb95ef4 dfb95ee8 5ee0: 807deec0 c5ac77bf dfb95f14 00000000 838da381 40946400 20000140 838da380 5f00: 00000005 83fa1880 dfb95fa4 dfb95f18 8059c2ac 8144588c ecac8b10 83fa1880 5f20: dfb95f3c dfb95f30 81b058d4 81b057a0 dfb95f54 dfb95f40 8025a4dc 8028c2bc 5f40: dfb95fb0 40000000 dfb95f84 dfb95f58 80220be0 8025a498 00000000 82a1c33c 5f60: dfb95fb0 0013e940 ecac8b10 80220b34 00000000 c5ac77bf dfb95fac 00000000 5f80: 00000000 00346310 00000036 8020029c 83fa1880 00000036 00000000 dfb95fa8 5fa0: 80200060 8059c074 00000000 00000000 00000005 40946400 20000140 00000000 5fc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76fe80dc 5fe0: 76fe7e88 76fe7e78 00018e58 001307a0 60000010 00000005 00000000 00000000 Call trace: [<8144d3c0>] (parport_attach) from [<814490a4>] (comedi_device_attach+0x108/0x244 drivers/comedi/drivers.c:1101) r6:00000000 r5:81e27988 r4:82bd26a0 [<81448f9c>] (comedi_device_attach) from [<814448b0>] (do_devconfig_ioctl+0xd4/0x21c drivers/comedi/comedi_fops.c:930) r10:83fa1880 r9:00000005 r8:00000001 r7:40946400 r6:b5403587 r5:8334b6c0 r4:20000140 [<814447dc>] (do_devconfig_ioctl) from [<81445bd4>] (comedi_unlocked_ioctl+0x354/0x1db8 drivers/comedi/comedi_fops.c:2302) r8:00000001 r7:40946400 r6:20000140 r5:8334b6c0 r4:838da380 [<81445880>] (comedi_unlocked_ioctl) from [<8059c2ac>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<81445880>] (comedi_unlocked_ioctl) from [<8059c2ac>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<81445880>] (comedi_unlocked_ioctl) from [<8059c2ac>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<81445880>] (comedi_unlocked_ioctl) from [<8059c2ac>] (sys_ioctl+0x244/0xb5c fs/ioctl.c:583) r10:83fa1880 r9:00000005 r8:838da380 r7:20000140 r6:40946400 r5:838da381 r4:00000000 [<8059c068>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfb95fa8 to 0xdfb95ff0) 5fa0: 00000000 00000000 00000005 40946400 20000140 00000000 5fc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76fe80dc 5fe0: 76fe7e88 76fe7e78 00018e58 001307a0 r10:00000036 r9:83fa1880 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