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: 26795 Comm: syz.6.2966 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 : [<813dc260>] lr : [<813dc24c>] psr: 60090013 sp : df9d9cb8 ip : df9d9cb8 fp : df9d9cd4 r10: 00000000 r9 : 00000000 r8 : 00000084 r7 : 00004f27 r6 : 0000009b r5 : 841ac180 r4 : 00004f2a r3 : 0000009b r2 : fee04f2a r1 : 00000001 r0 : 841ac180 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 849ce880 DAC: fffffffd Register r0 information: slab kmalloc-192 start 841ac180 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 841ac180 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 0xdf9d8000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2609 Register r12 information: 2-page vmalloc region starting at 0xdf9d8000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2609 Process syz.6.2966 (pid: 26795, stack limit = 0xdf9d8000) Stack: (0xdf9d9cb8 to 0xdf9da000) 9ca0: 813dc200 841ac180 9cc0: 00004f27 00004f27 df9d9cf4 df9d9cd8 813dbf38 813dc20c 00004f27 8050a85c 9ce0: 862e6800 862e6800 df9d9d14 df9d9cf8 813dc2f8 813dbeec 862e6800 841ac180 9d00: df9d9da4 00004f27 df9d9d54 df9d9d18 813dc4ec 813dc278 8079e04c 86155880 9d20: 828215f0 00000000 00000000 829d240c 841ac180 841ac1c4 df9d9d90 841ac180 9d40: 00000000 82b25910 df9d9d8c df9d9d58 813cb3e8 813dc43c 200000c0 00000000 9d60: df9d9d7c 200000c0 841ac180 b5403587 200000c0 83bf0c00 40946400 00000003 9d80: df9d9e4c df9d9d90 813c6f34 813cb2ec 35353238 00000000 00000000 00000000 9da0: 00000000 00004f27 00000005 00000002 00000401 00000001 00000cc7 00000fff 9dc0: 5c952399 00000005 000003ff 00000802 00001600 00000001 00000001 00000000 9de0: 0000e1cb 00000006 00000004 00000003 00000001 80000089 fffffffd 00000000 9e00: fffffff5 ffffeadb 00000003 0000003c 00000008 00000004 08000000 00000007 9e20: 00000000 8e6c37e9 00000000 849a6780 841ac180 200000c0 200000c0 83bf0c00 9e40: df9d9f14 df9d9e50 813c7f00 813c6e40 00000000 00000000 00000000 8e6c37e9 9e60: 00000000 00000000 824625b4 0000005f 83e30c28 841ac1b0 84118ef4 83bf0c00 9e80: df9d9ee4 df9d9e90 807a7ab8 8079e204 00000064 00000001 00000000 df9d9eac 9ea0: 8a0e1cd0 8342e330 00006400 0000000b df9d9ea0 00000000 df9d9d30 8e6c37e9 9ec0: 849a6780 40946400 200000c0 200000c0 849a6780 00000003 df9d9ef4 df9d9ee8 9ee0: 807a7bd8 8e6c37e9 df9d9f14 40946400 00000000 849a6781 200000c0 849a6780 9f00: 00000003 83bf0c00 df9d9fa4 df9d9f18 80578f40 813c7930 ecac8b10 83bf0c00 9f20: df9d9f3c df9d9f30 81a61ce0 81a61bb0 df9d9f54 df9d9f40 8025c484 8028d914 9f40: df9d9fb0 40000000 df9d9f84 df9d9f58 802229ec 8025c440 00000000 8281cfb4 9f60: df9d9fb0 0014cf70 ecac8b10 80222940 00000000 8e6c37e9 df9d9fac 00000000 9f80: 00000000 00316308 00000036 8020029c 83bf0c00 00000036 00000000 df9d9fa8 9fa0: 80200060 80578e1c 00000000 00000000 00000003 40946400 200000c0 00000000 9fc0: 00000000 00000000 00316308 00000036 00300000 00000000 00006364 76f050bc 9fe0: 76f04ec0 76f04eb0 00019294 00132a10 60000010 00000003 00000000 00000000 Call trace: [<813dc200>] (subdev_8255_io) from [<813dbf38>] (subdev_8255_do_config+0x58/0x60 drivers/comedi/drivers/comedi_8255.c:115) r7:00004f27 r6:00004f27 r5:841ac180 r4:813dc200 [<813dbee0>] (subdev_8255_do_config) from [<813dc2f8>] (__subdev_8255_init drivers/comedi/drivers/comedi_8255.c:172 [inline]) [<813dbee0>] (subdev_8255_do_config) from [<813dc2f8>] (subdev_8255_io_init+0x8c/0x9c drivers/comedi/drivers/comedi_8255.c:192) r4:862e6800 [<813dc26c>] (subdev_8255_io_init) from [<813dc4ec>] (dev_8255_attach drivers/comedi/drivers/8255.c:83 [inline]) [<813dc26c>] (subdev_8255_io_init) from [<813dc4ec>] (dev_8255_attach+0xbc/0x114 drivers/comedi/drivers/8255.c:46) r7:00004f27 r6:df9d9da4 r5:841ac180 r4:862e6800 [<813dc430>] (dev_8255_attach) from [<813cb3e8>] (comedi_device_attach+0x108/0x250 drivers/comedi/drivers.c:1007) r10:82b25910 r9:00000000 r8:841ac180 r7:df9d9d90 r6:841ac1c4 r5:841ac180 r4:829d240c [<813cb2e0>] (comedi_device_attach) from [<813c6f34>] (do_devconfig_ioctl+0x100/0x220 drivers/comedi/comedi_fops.c:872) r10:00000003 r9:40946400 r8:83bf0c00 r7:200000c0 r6:b5403587 r5:841ac180 r4:200000c0 [<813c6e34>] (do_devconfig_ioctl) from [<813c7f00>] (comedi_unlocked_ioctl+0x5dc/0x1c50 drivers/comedi/comedi_fops.c:2178) r8:83bf0c00 r7:200000c0 r6:200000c0 r5:841ac180 r4:849a6780 [<813c7924>] (comedi_unlocked_ioctl) from [<80578f40>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<813c7924>] (comedi_unlocked_ioctl) from [<80578f40>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<813c7924>] (comedi_unlocked_ioctl) from [<80578f40>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<813c7924>] (comedi_unlocked_ioctl) from [<80578f40>] (sys_ioctl+0x130/0xba0 fs/ioctl.c:583) r10:83bf0c00 r9:00000003 r8:849a6780 r7:200000c0 r6:849a6781 r5:00000000 r4:40946400 [<80578e10>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdf9d9fa8 to 0xdf9d9ff0) 9fa0: 00000000 00000000 00000003 40946400 200000c0 00000000 9fc0: 00000000 00000000 00316308 00000036 00300000 00000000 00006364 76f050bc 9fe0: 76f04ec0 76f04eb0 00019294 00132a10 r10:00000036 r9:83bf0c00 r8:8020029c r7:00000036 r6:00316308 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