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: 15791 Comm: syz.7.2296 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 : [<813b85a8>] lr : [<813b8594>] psr: 60010113 sp : dfb8dcb8 ip : dfb8dcb8 fp : dfb8dcd4 r10: 00000000 r9 : 00000000 r8 : 00000084 r7 : 00004f27 r6 : 0000009b r5 : 84160900 r4 : 00004f2a r3 : 0000009b r2 : fee04f2a r1 : 00000001 r0 : 84160900 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 858d62c0 DAC: fffffffd Register r0 information: slab kmalloc-192 start 84160900 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 84160900 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 0xdfb8c000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2605 Register r12 information: 2-page vmalloc region starting at 0xdfb8c000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2605 Process syz.7.2296 (pid: 15791, stack limit = 0xdfb8c000) Stack: (0xdfb8dcb8 to 0xdfb8e000) dca0: 813b8548 84160900 dcc0: 00004f27 00004f27 dfb8dcf4 dfb8dcd8 813b8280 813b8554 00004f27 80503b98 dce0: 84f50000 84f50000 dfb8dd14 dfb8dcf8 813b8640 813b8234 84f50000 84160900 dd00: dfb8dda4 00004f27 dfb8dd54 dfb8dd18 813b8834 813b85c0 82ae3d60 8626bc80 dd20: 82821598 00000000 00000000 829d00c4 84160900 84160944 dfb8dd90 84160900 dd40: 00000000 82b16f00 dfb8dd8c dfb8dd58 813a7738 813b8784 200000c0 00000000 dd60: dfb8dd7c 200000c0 84160900 b5403587 200000c0 8645a400 40946400 00000003 dd80: dfb8de4c dfb8dd90 813a32b8 813a763c 35353238 00000000 00000000 00000000 dda0: 00000000 00004f27 00000009 00000002 00000401 00000001 00000cc7 00000fff ddc0: 5c952399 00000005 000003ff 00000802 00001600 fffffffe 00000001 00000009 dde0: 0000e1cb 00000006 00000004 00000003 00000396 80000089 fffffffd 00000000 de00: fffffff5 ffffeadb 00000003 0000003c 00000008 00000004 08000000 dffffffa de20: 00000000 2e72a184 00000000 846e0840 84160900 200000c0 200000c0 8645a400 de40: dfb8df14 dfb8de50 813a4284 813a31c4 00000000 00000000 00000000 2e72a184 de60: 00000000 00000000 8247054c 0000005f 83c25058 84160930 8417648c 8645a400 de80: dfb8dee4 dfb8de90 80797a1c 8078dd80 00000064 00000001 00000000 dfb8deac dea0: 8619e010 8342edd0 00006400 0000000b dfb8dea0 00000000 00000000 2e72a184 dec0: 846e0840 40946400 200000c0 200000c0 846e0840 00000003 dfb8def4 dfb8dee8 dee0: 80797b3c 2e72a184 dfb8df14 40946400 00000000 846e0841 200000c0 846e0840 df00: 00000003 8645a400 dfb8dfa4 dfb8df18 8056cd60 813a3cb4 ecac8b10 8645a400 df20: dfb8df3c dfb8df30 81a394f8 81a393c8 dfb8df54 dfb8df40 8025e490 8028ef64 df40: dfb8dfb0 40000000 dfb8df84 dfb8df58 802229ec 8025e44c 00000000 8281cddc df60: dfb8dfb0 0014c820 ecac8b10 80222940 00000000 2e72a184 dfb8dfac 00000000 df80: 00000000 002f6308 00000036 8020029c 8645a400 00000036 00000000 dfb8dfa8 dfa0: 80200060 8056cc3c 00000000 00000000 00000003 40946400 200000c0 00000000 dfc0: 00000000 00000000 002f6308 00000036 002e0000 00000000 00006364 76f2a0bc dfe0: 76f29ec0 76f29eb0 0001948c 001322c0 60000010 00000003 00000000 00000000 Call trace: [<813b8548>] (subdev_8255_io) from [<813b8280>] (subdev_8255_do_config+0x58/0x60 drivers/comedi/drivers/comedi_8255.c:115) r7:00004f27 r6:00004f27 r5:84160900 r4:813b8548 [<813b8228>] (subdev_8255_do_config) from [<813b8640>] (__subdev_8255_init drivers/comedi/drivers/comedi_8255.c:172 [inline]) [<813b8228>] (subdev_8255_do_config) from [<813b8640>] (subdev_8255_io_init+0x8c/0x9c drivers/comedi/drivers/comedi_8255.c:192) r4:84f50000 [<813b85b4>] (subdev_8255_io_init) from [<813b8834>] (dev_8255_attach drivers/comedi/drivers/8255.c:83 [inline]) [<813b85b4>] (subdev_8255_io_init) from [<813b8834>] (dev_8255_attach+0xbc/0x114 drivers/comedi/drivers/8255.c:46) r7:00004f27 r6:dfb8dda4 r5:84160900 r4:84f50000 [<813b8778>] (dev_8255_attach) from [<813a7738>] (comedi_device_attach+0x108/0x250 drivers/comedi/drivers.c:1006) r10:82b16f00 r9:00000000 r8:84160900 r7:dfb8dd90 r6:84160944 r5:84160900 r4:829d00c4 [<813a7630>] (comedi_device_attach) from [<813a32b8>] (do_devconfig_ioctl+0x100/0x220 drivers/comedi/comedi_fops.c:872) r10:00000003 r9:40946400 r8:8645a400 r7:200000c0 r6:b5403587 r5:84160900 r4:200000c0 [<813a31b8>] (do_devconfig_ioctl) from [<813a4284>] (comedi_unlocked_ioctl+0x5dc/0x1c24 drivers/comedi/comedi_fops.c:2173) r8:8645a400 r7:200000c0 r6:200000c0 r5:84160900 r4:846e0840 [<813a3ca8>] (comedi_unlocked_ioctl) from [<8056cd60>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<813a3ca8>] (comedi_unlocked_ioctl) from [<8056cd60>] (do_vfs_ioctl fs/ioctl.c:552 [inline]) [<813a3ca8>] (comedi_unlocked_ioctl) from [<8056cd60>] (__do_sys_ioctl fs/ioctl.c:596 [inline]) [<813a3ca8>] (comedi_unlocked_ioctl) from [<8056cd60>] (sys_ioctl+0x130/0xba0 fs/ioctl.c:584) r10:8645a400 r9:00000003 r8:846e0840 r7:200000c0 r6:846e0841 r5:00000000 r4:40946400 [<8056cc30>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfb8dfa8 to 0xdfb8dff0) dfa0: 00000000 00000000 00000003 40946400 200000c0 00000000 dfc0: 00000000 00000000 002f6308 00000036 002e0000 00000000 00006364 76f2a0bc dfe0: 76f29ec0 76f29eb0 0001948c 001322c0 r10:00000036 r9:8645a400 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