8<--- cut here --- Unable to handle kernel paging request at virtual address fee04e2a when write [fee04e2a] *pgd=80000080007003, *pmd=00000000 Internal error: Oops: a06 [#1] SMP ARM Modules linked in: CPU: 0 UID: 0 PID: 9818 Comm: syz.1.1667 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 : [<8140e268>] lr : [<8140e254>] psr: 60000013 sp : df9d5cb8 ip : df9d5cb8 fp : df9d5cd4 r10: 00000000 r9 : 00000084 r8 : df9d5da4 r7 : 00004e27 r6 : 0000009b r5 : 840b0780 r4 : 00004e2a r3 : 0000009b r2 : fee04e2a r1 : 00000001 r0 : 840b0780 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 85f48f40 DAC: fffffffd Register r0 information: slab kmalloc-192 start 840b0780 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 840b0780 pointer offset 0 size 192 Register r6 information: non-paged memory Register r7 information: non-paged memory Register r8 information: 2-page vmalloc region starting at 0xdf9d4000 allocated at kernel_clone+0xac/0x3f4 kernel/fork.c:2651 Register r9 information: non-paged memory Register r10 information: NULL pointer Register r11 information: 2-page vmalloc region starting at 0xdf9d4000 allocated at kernel_clone+0xac/0x3f4 kernel/fork.c:2651 Register r12 information: 2-page vmalloc region starting at 0xdf9d4000 allocated at kernel_clone+0xac/0x3f4 kernel/fork.c:2651 Process syz.1.1667 (pid: 9818, stack limit = 0xdf9d4000) Stack: (0xdf9d5cb8 to 0xdf9d6000) 5ca0: 8140e208 00004e27 5cc0: 840b0780 00004e27 df9d5cf4 df9d5cd8 8140df44 8140e214 00004e27 805161bc 5ce0: 84dfd400 84dfd400 df9d5d14 df9d5cf8 8140e2fc 8140def8 840b0780 00000000 5d00: 84dfd400 00004e27 df9d5d54 df9d5d18 8140e4ac 8140e280 82b04544 86a9d880 5d20: 828215b0 00000000 00000000 829d4a44 840b0780 00000000 df9d5d90 840b0780 5d40: 00000000 82b29b30 df9d5d8c df9d5d58 813fcea0 8140e444 40946400 00000000 5d60: df9d5d7c 20000440 840b0780 b5403587 40946400 84c43000 00000003 840b07b0 5d80: df9d5e4c df9d5d90 813f87d8 813fcda0 35353238 00000000 00000000 00000000 5da0: 00000000 00004e27 00000005 00000003 00000b55 000000e7 80000008 00000000 5dc0: 00000a82 0000ff46 00000100 00000cf3 00000009 000001d8 00000002 00000006 5de0: 00000101 00000001 0001008b 00000003 00000000 00000004 80000001 00000008 5e00: 02000007 0000000b 00000005 0000003c 00000005 7fffffff 0000ffff fffffff8 5e20: 00000000 2efef8a9 00000000 85158900 840b0780 20000440 40946400 84c43000 5e40: df9d5f14 df9d5e50 813f9358 813f8710 00000000 2efef8a9 00000000 00000000 5e60: 824b15ec df9d5ea4 0000005f 842ae448 00000064 84106abc df9d5ee4 df9d5e88 5e80: 807b3fb4 807aa630 00000064 00000001 00000000 df9d5ea4 85d10790 834f7ee0 5ea0: 00006400 0000000b df9d5e98 00000000 00000000 2efef8a9 00000000 85158900 5ec0: 40946400 20000440 20000440 85158900 00000003 84c43000 df9d5ef4 df9d5ee8 5ee0: 807b40e4 2efef8a9 df9d5f14 00000000 85158901 40946400 20000440 85158900 5f00: 00000003 84c43000 df9d5fa4 df9d5f18 805821a4 813f9260 ecac8b10 84c43000 5f20: df9d5f3c df9d5f30 81aa6d38 81aa6c08 df9d5f54 df9d5f40 8025ba7c 8028ef68 5f40: df9d5fb0 40000000 df9d5f84 df9d5f58 80221a54 8025ba38 00000000 8281cf7c 5f60: df9d5fb0 0013ddc0 ecac8b10 802219a8 00000000 2efef8a9 df9d5fac 00000000 5f80: 00000000 00346310 00000036 8020029c 84c43000 00000036 00000000 df9d5fa8 5fa0: 80200060 80581f6c 00000000 00000000 00000003 40946400 20000440 00000000 5fc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76f490dc 5fe0: 76f48e88 76f48e78 00018734 0012fc20 60000010 00000003 00000000 00000000 Call trace: [<8140e208>] (subdev_8255_io) from [<8140df44>] (subdev_8255_do_config+0x58/0x60 drivers/comedi/drivers/comedi_8255.c:115) r7:00004e27 r6:840b0780 r5:00004e27 r4:8140e208 [<8140deec>] (subdev_8255_do_config) from [<8140e2fc>] (__subdev_8255_init drivers/comedi/drivers/comedi_8255.c:172 [inline]) [<8140deec>] (subdev_8255_do_config) from [<8140e2fc>] (subdev_8255_io_init+0x88/0x98 drivers/comedi/drivers/comedi_8255.c:192) r4:84dfd400 [<8140e274>] (subdev_8255_io_init) from [<8140e4ac>] (dev_8255_attach drivers/comedi/drivers/8255.c:82 [inline]) [<8140e274>] (subdev_8255_io_init) from [<8140e4ac>] (dev_8255_attach+0x74/0x120 drivers/comedi/drivers/8255.c:46) r7:00004e27 r6:84dfd400 r5:00000000 r4:840b0780 [<8140e438>] (dev_8255_attach) from [<813fcea0>] (comedi_device_attach+0x10c/0x248 drivers/comedi/drivers.c:1069) r10:82b29b30 r9:00000000 r8:840b0780 r7:df9d5d90 r6:00000000 r5:840b0780 r4:829d4a44 [<813fcd94>] (comedi_device_attach) from [<813f87d8>] (do_devconfig_ioctl+0xd4/0x21c drivers/comedi/comedi_fops.c:928) r10:840b07b0 r9:00000003 r8:84c43000 r7:40946400 r6:b5403587 r5:840b0780 r4:20000440 [<813f8704>] (do_devconfig_ioctl) from [<813f9358>] (comedi_unlocked_ioctl+0x104/0x1c80 drivers/comedi/comedi_fops.c:2240) r8:84c43000 r7:40946400 r6:20000440 r5:840b0780 r4:85158900 [<813f9254>] (comedi_unlocked_ioctl) from [<805821a4>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<813f9254>] (comedi_unlocked_ioctl) from [<805821a4>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<813f9254>] (comedi_unlocked_ioctl) from [<805821a4>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<813f9254>] (comedi_unlocked_ioctl) from [<805821a4>] (sys_ioctl+0x244/0xb58 fs/ioctl.c:583) r10:84c43000 r9:00000003 r8:85158900 r7:20000440 r6:40946400 r5:85158901 r4:00000000 [<80581f60>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdf9d5fa8 to 0xdf9d5ff0) 5fa0: 00000000 00000000 00000003 40946400 20000440 00000000 5fc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76f490dc 5fe0: 76f48e88 76f48e78 00018734 0012fc20 r10:00000036 r9:84c43000 r8:8020029c r7:00000036 r6:00346310 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