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: 20149 Comm: syz.1.4829 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 : [<813b8bd8>] lr : [<813b8bc4>] psr: 60000013 sp : dfa31cb8 ip : dfa31cb8 fp : dfa31cd4 r10: 00000000 r9 : 00000000 r8 : 00000084 r7 : 00004f27 r6 : 0000009b r5 : 842a0180 r4 : 00004f2a r3 : 0000009b r2 : fee04f2a r1 : 00000001 r0 : 842a0180 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 84ecf5c0 DAC: fffffffd Register r0 information: slab kmalloc-192 start 842a0180 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 842a0180 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 0xdfa30000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2605 Register r12 information: 2-page vmalloc region starting at 0xdfa30000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2605 Process syz.1.4829 (pid: 20149, stack limit = 0xdfa30000) Stack: (0xdfa31cb8 to 0xdfa32000) 1ca0: 813b8b78 842a0180 1cc0: 00004f27 00004f27 dfa31cf4 dfa31cd8 813b88b0 813b8b84 00004f27 80503b64 1ce0: 8540b000 8540b000 dfa31d14 dfa31cf8 813b8c70 813b8864 8540b000 842a0180 1d00: dfa31da4 00004f27 dfa31d54 dfa31d18 813b8e64 813b8bf0 8078dc50 84bae880 1d20: 828215b0 00000000 00000000 829d0144 842a0180 842a01c4 dfa31d90 842a0180 1d40: 00000000 82b16f40 dfa31d8c dfa31d58 813a7d68 813b8db4 200000c0 00000000 1d60: dfa31d7c 200000c0 842a0180 b5403587 200000c0 838b2400 40946400 00000003 1d80: dfa31e4c dfa31d90 813a38b4 813a7c6c 35353238 00000000 00000000 00000000 1da0: 00000000 00004f27 00000005 0000a007 00000401 00000001 00000007 00000fff 1dc0: 5c952399 00000595 000003ff 00000802 00001600 00000001 00000000 00000006 1de0: 0000e1cb 00000006 00000004 00000003 00000395 80000089 fffffffd 00000000 1e00: 00000006 ffffeadb 00000003 0001003c 00000008 00000004 08000000 00000005 1e20: 00000000 f663c9ce 00000000 85875900 842a0180 200000c0 200000c0 838b2400 1e40: dfa31f14 dfa31e50 813a4880 813a37c0 00000000 dfa31e54 dfa31e54 f663c9ce 1e60: 00000000 00000000 8247054c 0000005f 83dc4058 842a01b0 84265834 838b2400 1e80: dfa31ee4 dfa31e90 80797aa4 8078de08 00000064 00000001 00000000 dfa31eac 1ea0: 85c41250 834e2bb0 00006400 0000000b dfa31ea0 00000000 dfa31d30 f663c9ce 1ec0: 85875900 40946400 200000c0 200000c0 85875900 00000003 dfa31ef4 dfa31ee8 1ee0: 80797bc4 f663c9ce dfa31f14 40946400 00000000 85875901 200000c0 85875900 1f00: 00000003 838b2400 dfa31fa4 dfa31f18 8056cdc8 813a42b0 ecac8b10 838b2400 1f20: dfa31f3c dfa31f30 81a39df8 81a39cc8 dfa31f54 dfa31f40 8025e490 8028ef6c 1f40: dfa31fb0 40000000 dfa31f84 dfa31f58 802229ec 8025e44c 00000000 8281cddc 1f60: dfa31fb0 0014c820 ecac8b10 80222940 00000000 f663c9ce dfa31fac 00000000 1f80: 00000000 002f6308 00000036 8020029c 838b2400 00000036 00000000 dfa31fa8 1fa0: 80200060 8056cca4 00000000 00000000 00000003 40946400 200000c0 00000000 1fc0: 00000000 00000000 002f6308 00000036 002e0000 00000000 00006364 76f590bc 1fe0: 76f58ec0 76f58eb0 0001948c 001322c0 60000010 00000003 00000000 00000000 Call trace: [<813b8b78>] (subdev_8255_io) from [<813b88b0>] (subdev_8255_do_config+0x58/0x60 drivers/comedi/drivers/comedi_8255.c:115) r7:00004f27 r6:00004f27 r5:842a0180 r4:813b8b78 [<813b8858>] (subdev_8255_do_config) from [<813b8c70>] (__subdev_8255_init drivers/comedi/drivers/comedi_8255.c:172 [inline]) [<813b8858>] (subdev_8255_do_config) from [<813b8c70>] (subdev_8255_io_init+0x8c/0x9c drivers/comedi/drivers/comedi_8255.c:192) r4:8540b000 [<813b8be4>] (subdev_8255_io_init) from [<813b8e64>] (dev_8255_attach drivers/comedi/drivers/8255.c:83 [inline]) [<813b8be4>] (subdev_8255_io_init) from [<813b8e64>] (dev_8255_attach+0xbc/0x114 drivers/comedi/drivers/8255.c:46) r7:00004f27 r6:dfa31da4 r5:842a0180 r4:8540b000 [<813b8da8>] (dev_8255_attach) from [<813a7d68>] (comedi_device_attach+0x108/0x250 drivers/comedi/drivers.c:1007) r10:82b16f40 r9:00000000 r8:842a0180 r7:dfa31d90 r6:842a01c4 r5:842a0180 r4:829d0144 [<813a7c60>] (comedi_device_attach) from [<813a38b4>] (do_devconfig_ioctl+0x100/0x220 drivers/comedi/comedi_fops.c:872) r10:00000003 r9:40946400 r8:838b2400 r7:200000c0 r6:b5403587 r5:842a0180 r4:200000c0 [<813a37b4>] (do_devconfig_ioctl) from [<813a4880>] (comedi_unlocked_ioctl+0x5dc/0x1c50 drivers/comedi/comedi_fops.c:2178) r8:838b2400 r7:200000c0 r6:200000c0 r5:842a0180 r4:85875900 [<813a42a4>] (comedi_unlocked_ioctl) from [<8056cdc8>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<813a42a4>] (comedi_unlocked_ioctl) from [<8056cdc8>] (do_vfs_ioctl fs/ioctl.c:552 [inline]) [<813a42a4>] (comedi_unlocked_ioctl) from [<8056cdc8>] (__do_sys_ioctl fs/ioctl.c:596 [inline]) [<813a42a4>] (comedi_unlocked_ioctl) from [<8056cdc8>] (sys_ioctl+0x130/0xba0 fs/ioctl.c:584) r10:838b2400 r9:00000003 r8:85875900 r7:200000c0 r6:85875901 r5:00000000 r4:40946400 [<8056cc98>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfa31fa8 to 0xdfa31ff0) 1fa0: 00000000 00000000 00000003 40946400 200000c0 00000000 1fc0: 00000000 00000000 002f6308 00000036 002e0000 00000000 00006364 76f590bc 1fe0: 76f58ec0 76f58eb0 0001948c 001322c0 r10:00000036 r9:838b2400 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