8<--- cut here --- Unable to handle kernel paging request at virtual address fee0472a when write [fee0472a] *pgd=80000080007003, *pmd=00000000 Internal error: Oops: a06 [#1] SMP ARM Modules linked in: CPU: 0 UID: 0 PID: 4256 Comm: syz.1.163 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 : [<8141571c>] lr : [<81415708>] psr: 60000013 sp : e01b1cb0 ip : e01b1cb0 fp : e01b1ccc r10: 00000001 r9 : 00000084 r8 : e01b1d9c r7 : 00004727 r6 : 0000009b r5 : 845efc00 r4 : 0000472a r3 : 0000009b r2 : fee0472a r1 : 00000001 r0 : 845efc00 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 8531c0c0 DAC: fffffffd Register r0 information: slab kmalloc-192 start 845efc00 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 845efc00 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 0xe01b0000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2651 Register r9 information: non-paged memory Register r10 information: non-paged memory Register r11 information: 2-page vmalloc region starting at 0xe01b0000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2651 Register r12 information: 2-page vmalloc region starting at 0xe01b0000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2651 Process syz.1.163 (pid: 4256, stack limit = 0xe01b0000) Stack: (0xe01b1cb0 to 0xe01b2000) 1ca0: 814156bc 845efc00 00004727 00004727 1cc0: e01b1cec e01b1cd0 814153f4 814156c8 00004727 80514ee4 85cad800 85cad800 1ce0: e01b1d0c e01b1cf0 814157b4 814153a8 845efc00 00000000 85cad800 00004727 1d00: e01b1d4c e01b1d10 81415960 81415734 8280cc60 83e9b700 828217b0 00000000 1d20: 00000000 829d46a0 845efc00 845efc44 e01b1d88 845efc00 00000000 82b28ad8 1d40: e01b1d84 e01b1d50 81404490 814158f8 845efc30 00000000 e01b1d74 20000240 1d60: 845efc00 b5403587 845efc30 84680000 40946400 00000003 e01b1e44 e01b1d88 1d80: 813ffde8 81404394 35353238 00000000 00000000 00000000 00000000 00004727 1da0: 04000005 08001022 00000002 00000001 00006dc2 00000ffe 00000000 0000006c 1dc0: 000003df 0000200e 004003ff 00000004 fffff350 00000009 00000009 00000004 1de0: 000007ff 00000002 00000009 80000089 fffffffe 00000008 fffffff5 00008000 1e00: 00000004 000003a6 00000000 00001e9f 000000c6 dffffffa 00000000 893e6583 1e20: 00000000 85f83b40 845efc00 20000240 845efc30 84680000 e01b1f14 e01b1e48 1e40: 81400ddc 813ffcf4 00000000 00000000 00000000 00000000 00000000 893e6583 1e60: 00000000 00000000 824a35ec 0000005f 83fd3de0 00000064 846275ac 84680000 1e80: e01b1ee4 e01b1e90 807b7d30 807ae254 00000064 00000001 00000000 e01b1eac 1ea0: 852dd010 834fc908 00006400 0000000b e01b1ea0 00000000 00000000 893e6583 1ec0: 85f83b40 40946400 20000240 20000240 85f83b40 00000003 e01b1ef4 e01b1ee8 1ee0: 807b7e50 893e6583 e01b1f14 40946400 00000000 85f83b41 20000240 85f83b40 1f00: 00000003 84680000 e01b1fa4 e01b1f18 805854f4 8140082c ecac8b10 84680000 1f20: e01b1f3c e01b1f30 81aaf29c 81aaf16c e01b1f54 e01b1f40 8025bcbc 8028e07c 1f40: e01b1fb0 40000000 e01b1f84 e01b1f58 80221a38 8025bc78 00000000 8281d17c 1f60: e01b1fb0 0014c880 ecac8b10 8022198c 00000000 893e6583 e01b1fac 00000000 1f80: 00000000 00316310 00000036 8020029c 84680000 00000036 00000000 e01b1fa8 1fa0: 80200060 805853d0 00000000 00000000 00000003 40946400 20000240 00000000 1fc0: 00000000 00000000 00316310 00000036 00300000 00000000 00006364 76f670bc 1fe0: 76f66ec0 76f66eb0 0001929c 00132320 60000010 00000003 00000000 00000000 Call trace: [<814156bc>] (subdev_8255_io) from [<814153f4>] (subdev_8255_do_config+0x58/0x60 drivers/comedi/drivers/comedi_8255.c:115) r7:00004727 r6:00004727 r5:845efc00 r4:814156bc [<8141539c>] (subdev_8255_do_config) from [<814157b4>] (__subdev_8255_init drivers/comedi/drivers/comedi_8255.c:172 [inline]) [<8141539c>] (subdev_8255_do_config) from [<814157b4>] (subdev_8255_io_init+0x8c/0x9c drivers/comedi/drivers/comedi_8255.c:192) r4:85cad800 [<81415728>] (subdev_8255_io_init) from [<81415960>] (dev_8255_attach drivers/comedi/drivers/8255.c:82 [inline]) [<81415728>] (subdev_8255_io_init) from [<81415960>] (dev_8255_attach+0x74/0x120 drivers/comedi/drivers/8255.c:46) r7:00004727 r6:85cad800 r5:00000000 r4:845efc00 [<814158ec>] (dev_8255_attach) from [<81404490>] (comedi_device_attach+0x108/0x250 drivers/comedi/drivers.c:1069) r10:82b28ad8 r9:00000000 r8:845efc00 r7:e01b1d88 r6:845efc44 r5:845efc00 r4:829d46a0 [<81404388>] (comedi_device_attach) from [<813ffde8>] (do_devconfig_ioctl+0x100/0x220 drivers/comedi/comedi_fops.c:928) r10:00000003 r9:40946400 r8:84680000 r7:845efc30 r6:b5403587 r5:845efc00 r4:20000240 [<813ffce8>] (do_devconfig_ioctl) from [<81400ddc>] (comedi_unlocked_ioctl+0x5bc/0x1c2c drivers/comedi/comedi_fops.c:2240) r8:84680000 r7:845efc30 r6:20000240 r5:845efc00 r4:85f83b40 [<81400820>] (comedi_unlocked_ioctl) from [<805854f4>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<81400820>] (comedi_unlocked_ioctl) from [<805854f4>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<81400820>] (comedi_unlocked_ioctl) from [<805854f4>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<81400820>] (comedi_unlocked_ioctl) from [<805854f4>] (sys_ioctl+0x130/0xba0 fs/ioctl.c:583) r10:84680000 r9:00000003 r8:85f83b40 r7:20000240 r6:85f83b41 r5:00000000 r4:40946400 [<805853c4>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xe01b1fa8 to 0xe01b1ff0) 1fa0: 00000000 00000000 00000003 40946400 20000240 00000000 1fc0: 00000000 00000000 00316310 00000036 00300000 00000000 00006364 76f670bc 1fe0: 76f66ec0 76f66eb0 0001929c 00132320 r10:00000036 r9:84680000 r8:8020029c r7:00000036 r6:00316310 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