8<--- cut here --- Unable to handle kernel paging request at virtual address fee04f2a when write [fee04f2a] *pgd=80000080007003, *pmd=00000000 Internal error: Oops: a06 [#1] SMP ARM Modules linked in: CPU: 0 UID: 0 PID: 7969 Comm: syz.0.857 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 subdev_8255_io drivers/comedi/drivers/comedi_8255.c:47 [inline] PC is at subdev_8255_io+0x60/0x6c drivers/comedi/drivers/comedi_8255.c:43 LR is at subdev_8255_io drivers/comedi/drivers/comedi_8255.c:47 [inline] LR is at subdev_8255_io+0x4c/0x6c drivers/comedi/drivers/comedi_8255.c:43 pc : [<813b8ba8>] lr : [<813b8b94>] psr: 60000013 sp : dfa4dcb8 ip : dfa4dcb8 fp : dfa4dcd4 r10: 00000000 r9 : 00000000 r8 : 00000084 r7 : 00004f27 r6 : 0000009b r5 : 840886c0 r4 : 00004f2a r3 : 0000009b r2 : fee04f2a r1 : 00000001 r0 : 840886c0 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 85c15740 DAC: fffffffd Register r0 information: slab kmalloc-192 start 840886c0 pointer offset 0 size 192 Register r1 information: non-paged memory Register r2 information: 0-page vmalloc region starting at 0xfee00000 allocated at pci_reserve_io+0x0/0x38 arch/arm/mm/mmu.c:1055 Register r3 information: non-paged memory Register r4 information: non-paged memory Register r5 information: slab kmalloc-192 start 840886c0 pointer offset 0 size 192 Register r6 information: non-paged memory Register r7 information: non-paged memory Register r8 information: non-paged memory Register r9 information: NULL pointer Register r10 information: NULL pointer Register r11 information: 2-page vmalloc region starting at 0xdfa4c000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2605 Register r12 information: 2-page vmalloc region starting at 0xdfa4c000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2605 Process syz.0.857 (pid: 7969, stack limit = 0xdfa4c000) Stack: (0xdfa4dcb8 to 0xdfa4e000) dca0: 813b8b48 840886c0 dcc0: 00004f27 00004f27 dfa4dcf4 dfa4dcd8 813b8880 813b8b54 00004f27 80503b64 dce0: 84ef4000 84ef4000 dfa4dd14 dfa4dcf8 813b8c40 813b8834 84ef4000 840886c0 dd00: dfa4dda4 00004f27 dfa4dd54 dfa4dd18 813b8e34 813b8bc0 82ae3da0 83bd2c80 dd20: 828215b0 00000000 00000000 829d0144 840886c0 84088704 dfa4dd90 840886c0 dd40: 00000000 82b16f40 dfa4dd8c dfa4dd58 813a7d3c 813b8d84 200000c0 00000000 dd60: dfa4dd7c 200000c0 840886c0 b5403587 200000c0 85ae8c00 40946400 00000003 dd80: dfa4de4c dfa4dd90 813a3888 813a7c40 35353238 00000000 00000000 00000000 dda0: 00000000 00004f27 00000003 00010000 00000004 0000000c 00000cc6 00000010 ddc0: 00000007 0400000a fffffff8 00000003 00000000 00000000 00000001 00000006 dde0: 00000101 00000000 0001a449 00200003 00000000 00000007 00000009 fffffffe de00: 00000005 0000000b 01000e63 000004bc 00000008 00000006 02000000 fffffff4 de20: 00000000 c51cec00 00000000 85869e40 840886c0 200000c0 200000c0 85ae8c00 de40: dfa4df14 dfa4de50 813a4854 813a3794 00000000 00000000 00000000 c51cec00 de60: 00000000 00000000 8247054c 0000005f 83ca2a58 840886f0 8406f834 85ae8c00 de80: dfa4dee4 dfa4de90 80797aa4 8078de08 00000064 00000001 00000000 dfa4deac dea0: 857dd850 83434bb0 00006400 0000000b dfa4dea0 00000000 00000000 c51cec00 dec0: 85869e40 40946400 200000c0 200000c0 85869e40 00000003 dfa4def4 dfa4dee8 dee0: 80797bc4 c51cec00 dfa4df14 40946400 00000000 85869e41 200000c0 85869e40 df00: 00000003 85ae8c00 dfa4dfa4 dfa4df18 8056cdc8 813a4284 ecac8b10 85ae8c00 df20: dfa4df3c dfa4df30 81a39db8 81a39c88 dfa4df54 dfa4df40 8025e490 8028ef6c df40: dfa4dfb0 40000000 dfa4df84 dfa4df58 802229ec 8025e44c 00000000 8281cddc df60: dfa4dfb0 0014c820 ecac8b10 80222940 00000000 c51cec00 dfa4dfac 00000000 df80: 00000000 002f6308 00000036 8020029c 85ae8c00 00000036 00000000 dfa4dfa8 dfa0: 80200060 8056cca4 00000000 00000000 00000003 40946400 200000c0 00000000 dfc0: 00000000 00000000 002f6308 00000036 002e0000 00000000 00006364 76fba0bc dfe0: 76fb9ec0 76fb9eb0 0001948c 001322c0 60000010 00000003 00000000 00000000 Call trace: [<813b8b48>] (subdev_8255_io) from [<813b8880>] (subdev_8255_do_config+0x58/0x60 drivers/comedi/drivers/comedi_8255.c:115) r7:00004f27 r6:00004f27 r5:840886c0 r4:813b8b48 [<813b8828>] (subdev_8255_do_config) from [<813b8c40>] (__subdev_8255_init drivers/comedi/drivers/comedi_8255.c:172 [inline]) [<813b8828>] (subdev_8255_do_config) from [<813b8c40>] (subdev_8255_io_init+0x8c/0x9c drivers/comedi/drivers/comedi_8255.c:192) r4:84ef4000 [<813b8bb4>] (subdev_8255_io_init) from [<813b8e34>] (dev_8255_attach drivers/comedi/drivers/8255.c:83 [inline]) [<813b8bb4>] (subdev_8255_io_init) from [<813b8e34>] (dev_8255_attach+0xbc/0x114 drivers/comedi/drivers/8255.c:46) r7:00004f27 r6:dfa4dda4 r5:840886c0 r4:84ef4000 [<813b8d78>] (dev_8255_attach) from [<813a7d3c>] (comedi_device_attach+0x108/0x250 drivers/comedi/drivers.c:1007) r10:82b16f40 r9:00000000 r8:840886c0 r7:dfa4dd90 r6:84088704 r5:840886c0 r4:829d0144 [<813a7c34>] (comedi_device_attach) from [<813a3888>] (do_devconfig_ioctl+0x100/0x220 drivers/comedi/comedi_fops.c:872) r10:00000003 r9:40946400 r8:85ae8c00 r7:200000c0 r6:b5403587 r5:840886c0 r4:200000c0 [<813a3788>] (do_devconfig_ioctl) from [<813a4854>] (comedi_unlocked_ioctl+0x5dc/0x1c50 drivers/comedi/comedi_fops.c:2178) r8:85ae8c00 r7:200000c0 r6:200000c0 r5:840886c0 r4:85869e40 [<813a4278>] (comedi_unlocked_ioctl) from [<8056cdc8>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<813a4278>] (comedi_unlocked_ioctl) from [<8056cdc8>] (do_vfs_ioctl fs/ioctl.c:552 [inline]) [<813a4278>] (comedi_unlocked_ioctl) from [<8056cdc8>] (__do_sys_ioctl fs/ioctl.c:596 [inline]) [<813a4278>] (comedi_unlocked_ioctl) from [<8056cdc8>] (sys_ioctl+0x130/0xba0 fs/ioctl.c:584) r10:85ae8c00 r9:00000003 r8:85869e40 r7:200000c0 r6:85869e41 r5:00000000 r4:40946400 [<8056cc98>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfa4dfa8 to 0xdfa4dff0) dfa0: 00000000 00000000 00000003 40946400 200000c0 00000000 dfc0: 00000000 00000000 002f6308 00000036 002e0000 00000000 00006364 76fba0bc dfe0: 76fb9ec0 76fb9eb0 0001948c 001322c0 r10:00000036 r9:85ae8c00 r8:8020029c r7:00000036 r6:002f6308 r5:00000000 r4:00000000 Code: e6ef3076 e0842002 e7f32052 e2422612 (e5c23000) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: e6ef3076 uxtb r3, r6 4: e0842002 add r2, r4, r2 8: e7f32052 ubfx r2, r2, #0, #20 c: e2422612 sub r2, r2, #18874368 @ 0x1200000 * 10: e5c23000 strb r3, [r2] <-- trapping instruction