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: 16491 Comm: syz.3.10270 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 : [<813b8568>] lr : [<813b8554>] psr: 60000013 sp : dfd85cb8 ip : dfd85cb8 fp : dfd85cd4 r10: 00000000 r9 : 00000000 r8 : 00000084 r7 : 00004f27 r6 : 0000009b r5 : 840ed180 r4 : 00004f2a r3 : 0000009b r2 : fee04f2a r1 : 00000001 r0 : 840ed180 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 876a9c80 DAC: fffffffd Register r0 information: slab kmalloc-192 start 840ed180 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 840ed180 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 0xdfd84000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2605 Register r12 information: 2-page vmalloc region starting at 0xdfd84000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2605 Process syz.3.10270 (pid: 16491, stack limit = 0xdfd84000) Stack: (0xdfd85cb8 to 0xdfd86000) 5ca0: 813b8508 840ed180 5cc0: 00004f27 00004f27 dfd85cf4 dfd85cd8 813b8240 813b8514 00004f27 80503b98 5ce0: 85661800 85661800 dfd85d14 dfd85cf8 813b8600 813b81f4 85661800 840ed180 5d00: dfd85da4 00004f27 dfd85d54 dfd85d18 813b87f4 813b8580 82ae3d60 84ef1c00 5d20: 82821598 00000000 00000000 829d00c4 840ed180 840ed1c4 dfd85d90 840ed180 5d40: 00000000 82b16f00 dfd85d8c dfd85d58 813a76f8 813b8744 200000c0 00000000 5d60: dfd85d7c 200000c0 840ed180 b5403587 200000c0 8404b000 40946400 00000003 5d80: dfd85e4c dfd85d90 813a3278 813a75fc 35353238 00000000 00000000 00000000 5da0: 00000000 00004f27 00000005 00000002 00000401 00000001 00000cc7 00000fff 5dc0: 5c952399 00000005 000003ff 00000802 00001600 00000001 00000000 00000009 5de0: 0000e1cb 00000006 00000004 00000003 00000395 80000089 fffffffd 00000000 5e00: 00000006 ffffeadb 00000003 0001003c 00000008 00000004 08000000 00000005 5e20: 00000000 ef4ca71a 00000000 85932300 840ed180 200000c0 200000c0 8404b000 5e40: dfd85f14 dfd85e50 813a4244 813a3184 00000000 00000000 00000000 ef4ca71a 5e60: 00000000 00000000 8247054c 0000005f 83e53a58 840ed1b0 840dd3b4 8404b000 5e80: dfd85ee4 dfd85e90 807979b4 8078dd18 00000064 00000001 00000000 dfd85eac 5ea0: 84d89d90 834efbb0 00006400 0000000b dfd85ea0 00000000 00000000 ef4ca71a 5ec0: 85932300 40946400 200000c0 200000c0 85932300 00000003 dfd85ef4 dfd85ee8 5ee0: 80797ad4 ef4ca71a dfd85f14 40946400 00000000 85932301 200000c0 85932300 5f00: 00000003 8404b000 dfd85fa4 dfd85f18 8056cd60 813a3c74 ecac8b10 8404b000 5f20: dfd85f3c dfd85f30 81a394b8 81a39388 dfd85f54 dfd85f40 8025e490 8028ef64 5f40: dfd85fb0 40000000 dfd85f84 dfd85f58 802229ec 8025e44c 00000000 8281cddc 5f60: dfd85fb0 0014c820 ecac8b10 80222940 00000000 ef4ca71a dfd85fac 00000000 5f80: 00000000 002f6308 00000036 8020029c 8404b000 00000036 00000000 dfd85fa8 5fa0: 80200060 8056cc3c 00000000 00000000 00000003 40946400 200000c0 00000000 5fc0: 00000000 00000000 002f6308 00000036 002e0000 00000000 00006364 76fe90bc 5fe0: 76fe8ec0 76fe8eb0 0001948c 001322c0 60000010 00000003 00000000 00000000 Call trace: [<813b8508>] (subdev_8255_io) from [<813b8240>] (subdev_8255_do_config+0x58/0x60 drivers/comedi/drivers/comedi_8255.c:115) r7:00004f27 r6:00004f27 r5:840ed180 r4:813b8508 [<813b81e8>] (subdev_8255_do_config) from [<813b8600>] (__subdev_8255_init drivers/comedi/drivers/comedi_8255.c:172 [inline]) [<813b81e8>] (subdev_8255_do_config) from [<813b8600>] (subdev_8255_io_init+0x8c/0x9c drivers/comedi/drivers/comedi_8255.c:192) r4:85661800 [<813b8574>] (subdev_8255_io_init) from [<813b87f4>] (dev_8255_attach drivers/comedi/drivers/8255.c:83 [inline]) [<813b8574>] (subdev_8255_io_init) from [<813b87f4>] (dev_8255_attach+0xbc/0x114 drivers/comedi/drivers/8255.c:46) r7:00004f27 r6:dfd85da4 r5:840ed180 r4:85661800 [<813b8738>] (dev_8255_attach) from [<813a76f8>] (comedi_device_attach+0x108/0x250 drivers/comedi/drivers.c:1006) r10:82b16f00 r9:00000000 r8:840ed180 r7:dfd85d90 r6:840ed1c4 r5:840ed180 r4:829d00c4 [<813a75f0>] (comedi_device_attach) from [<813a3278>] (do_devconfig_ioctl+0x100/0x220 drivers/comedi/comedi_fops.c:872) r10:00000003 r9:40946400 r8:8404b000 r7:200000c0 r6:b5403587 r5:840ed180 r4:200000c0 [<813a3178>] (do_devconfig_ioctl) from [<813a4244>] (comedi_unlocked_ioctl+0x5dc/0x1c24 drivers/comedi/comedi_fops.c:2173) r8:8404b000 r7:200000c0 r6:200000c0 r5:840ed180 r4:85932300 [<813a3c68>] (comedi_unlocked_ioctl) from [<8056cd60>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<813a3c68>] (comedi_unlocked_ioctl) from [<8056cd60>] (do_vfs_ioctl fs/ioctl.c:552 [inline]) [<813a3c68>] (comedi_unlocked_ioctl) from [<8056cd60>] (__do_sys_ioctl fs/ioctl.c:596 [inline]) [<813a3c68>] (comedi_unlocked_ioctl) from [<8056cd60>] (sys_ioctl+0x130/0xba0 fs/ioctl.c:584) r10:8404b000 r9:00000003 r8:85932300 r7:200000c0 r6:85932301 r5:00000000 r4:40946400 [<8056cc30>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfd85fa8 to 0xdfd85ff0) 5fa0: 00000000 00000000 00000003 40946400 200000c0 00000000 5fc0: 00000000 00000000 002f6308 00000036 002e0000 00000000 00006364 76fe90bc 5fe0: 76fe8ec0 76fe8eb0 0001948c 001322c0 r10:00000036 r9:8404b000 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