8<--- cut here --- Unable to handle kernel paging request at virtual address fee04f27 when write [fee04f27] *pgd=80000080007003 , *pmd=00000000 Internal error: Oops: a06 [#1] SMP ARM Modules linked in: CPU: 1 UID: 0 PID: 5942 Comm: syz.2.450 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:289 [inline] PC is at parport_attach+0x174/0x1d0 drivers/comedi/drivers/comedi_parport.c:224 LR is at parport_attach drivers/comedi/drivers/comedi_parport.c:289 [inline] LR is at parport_attach+0x164/0x1d0 drivers/comedi/drivers/comedi_parport.c:224 pc : [<8143617c>] lr : [<8143616c>] psr: 60000013 sp : dfbcdd30 ip : dfbcdd30 fp : dfbcdd54 r10: 82b2f0bc r9 : 00000003 r8 : 8465ac00 r7 : dfbcdd90 r6 : 8465ac00 r5 : 00000000 r4 : 00000000 r3 : fee04f27 r2 : 81e24ef8 r1 : 00000001 r0 : 81435dec Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 86c3a6c0 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:1055 Register r4 information: NULL pointer Register r5 information: NULL pointer Register r6 information: slab kmalloc-192 start 8465ac00 pointer offset 0 size 192 Register r7 information: 2-page vmalloc region starting at 0xdfbcc000 allocated at kernel_clone+0xac/0x42c kernel/fork.c:2653 Register r8 information: slab kmalloc-192 start 8465ac00 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 0xdfbcc000 allocated at kernel_clone+0xac/0x42c kernel/fork.c:2653 Register r12 information: 2-page vmalloc region starting at 0xdfbcc000 allocated at kernel_clone+0xac/0x42c kernel/fork.c:2653 Process syz.2.450 (pid: 5942, stack limit = 0xdfbcc000) Stack: (0xdfbcdd30 to 0xdfbce000) dd20: dfbcdd4c dfbcdd40 829d6b1c 829d6b1c dd40: 81e253b8 00000000 dfbcdd8c dfbcdd58 81431cf0 81436014 40946400 00000000 dd60: dfbcdd7c 200000c0 8465ac00 b5403587 40946400 00000003 00000004 831e0000 dd80: dfbcde4c dfbcdd90 8142d4fc 81431bf0 656d6f63 705f6964 6f707261 00007472 dda0: 00000000 00004f27 00000000 00010000 00000004 00000003 00000cc7 00000004 ddc0: 00080008 0000000e 00000003 00000002 00000007 00000007 00000004 00000006 dde0: 00001000 00000000 0001a44d 00000003 3fff7fff 00000089 00000010 00800001 de00: 20001e58 0080000b 00000e69 0000003c 00000008 00000006 ffffffff effffff8 de20: 00000000 0f9bd277 00000000 85bd7000 8465ac00 200000c0 40946400 00000003 de40: dfbcdf14 dfbcde50 8142e820 8142d434 00000000 0f9bd277 00000000 00000000 de60: 824b957c dfbcdea4 0000005f 8419c250 00000064 8465ac30 dfbcdee4 dfbcde88 de80: 807d0ab0 807c6e88 00000064 00000001 00000000 dfbcdea4 865e3310 83433f68 dea0: 00006400 0000000b dfbcde98 00000000 00000000 0f9bd277 00000000 85bd7000 dec0: 40946400 200000c0 200000c0 85bd7000 00000004 831e0000 dfbcdef4 dfbcdee8 dee0: 807d0be0 0f9bd277 dfbcdf14 00000000 85bd7001 40946400 200000c0 85bd7000 df00: 00000004 831e0000 dfbcdfa4 dfbcdf18 80591278 8142e4d8 ecac8b10 831e0000 df20: dfbcdf3c dfbcdf30 81ae8614 81ae84e0 dfbcdf54 dfbcdf40 8025a894 8028c450 df40: dfbcdfb0 40000000 dfbcdf84 dfbcdf58 80220bf8 8025a850 00000000 8281d27c df60: dfbcdfb0 0013e4a0 ecac8b10 80220b4c 00000000 0f9bd277 dfbcdfac 00000000 df80: 00000000 00346310 00000036 8020029c 831e0000 00000036 00000000 dfbcdfa8 dfa0: 80200060 80591040 00000000 00000000 00000004 40946400 200000c0 00000000 dfc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76f020dc dfe0: 76f01e88 76f01e78 00018bc4 00130300 60000010 00000004 00000000 00000000 Call trace: [<81436008>] (parport_attach) from [<81431cf0>] (comedi_device_attach+0x10c/0x248 drivers/comedi/drivers.c:1077) r6:00000000 r5:81e253b8 r4:829d6b1c [<81431be4>] (comedi_device_attach) from [<8142d4fc>] (do_devconfig_ioctl+0xd4/0x21c drivers/comedi/comedi_fops.c:930) r10:831e0000 r9:00000004 r8:00000003 r7:40946400 r6:b5403587 r5:8465ac00 r4:200000c0 [<8142d428>] (do_devconfig_ioctl) from [<8142e820>] (comedi_unlocked_ioctl+0x354/0x1dbc drivers/comedi/comedi_fops.c:2302) r8:00000003 r7:40946400 r6:200000c0 r5:8465ac00 r4:85bd7000 [<8142e4cc>] (comedi_unlocked_ioctl) from [<80591278>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<8142e4cc>] (comedi_unlocked_ioctl) from [<80591278>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<8142e4cc>] (comedi_unlocked_ioctl) from [<80591278>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<8142e4cc>] (comedi_unlocked_ioctl) from [<80591278>] (sys_ioctl+0x244/0xb5c fs/ioctl.c:583) r10:831e0000 r9:00000004 r8:85bd7000 r7:200000c0 r6:40946400 r5:85bd7001 r4:00000000 [<80591034>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfbcdfa8 to 0xdfbcdff0) dfa0: 00000000 00000000 00000004 40946400 200000c0 00000000 dfc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76f020dc dfe0: 76f01e88 76f01e78 00018bc4 00130300 r10:00000036 r9:831e0000 r8:8020029c r7:00000036 r6:00346310 r5:00000000 r4:00000000 Code: e596306c e3a04000 e7f33053 e2433612 (e5c34000) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: e596306c ldr r3, [r6, #108] @ 0x6c 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