8<--- cut here --- Unable to handle kernel paging request at virtual address fee00023 when write [fee00023] *pgd=80000080007003, *pmd=00000000 Internal error: Oops: a06 [#1] SMP ARM Modules linked in: CPU: 0 UID: 0 PID: 8887 Comm: syz.1.1309 Not tainted syzkaller #0 PREEMPT Hardware name: ARM-Versatile Express PC is at __raw_writeb arch/arm/include/asm/io.h:99 [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 : [<814a3ef4>] lr : [<814a3ee0>] psr: 60000013 sp : dfda9cb8 ip : dfda9cb8 fp : dfda9cd4 r10: 00000020 r9 : 00000004 r8 : dfda9da4 r7 : 00000000 r6 : 0000009b r5 : 84600840 r4 : 00000023 r3 : 0000009b r2 : fee00023 r1 : 00000001 r0 : 84600840 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 8670d140 DAC: fffffffd Register r0 information: slab kmalloc-192 start 84600840 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:1048 Register r3 information: non-paged memory Register r4 information: non-paged memory Register r5 information: slab kmalloc-192 start 84600840 pointer offset 0 size 192 Register r6 information: non-paged memory Register r7 information: NULL pointer Register r8 information: 2-page vmalloc region starting at 0xdfda8000 allocated at kernel_clone+0xc4/0x43c kernel/fork.c:2748 Register r9 information: non-paged memory Register r10 information: non-paged memory Register r11 information: 2-page vmalloc region starting at 0xdfda8000 allocated at kernel_clone+0xc4/0x43c kernel/fork.c:2748 Register r12 information: 2-page vmalloc region starting at 0xdfda8000 allocated at kernel_clone+0xc4/0x43c kernel/fork.c:2748 Process syz.1.1309 (pid: 8887, stack limit = 0xdfda8000) Stack: (0xdfda9cb8 to 0xdfdaa000) 9ca0: 814a3e94 00000020 9cc0: 84600840 00000000 dfda9cf4 dfda9cd8 814a3bd0 814a3ea0 00000020 805476f0 9ce0: 87188b40 87188b40 dfda9d14 dfda9cf8 814a3f88 814a3b84 84600840 00000000 9d00: 87188b40 00000000 dfda9d54 dfda9d18 814a4138 814a3f0c ffffffff 00000004 9d20: 82a22dc0 00000000 00000000 82bd9a60 84600840 00000000 dfda9d90 84600840 9d40: 00000000 82d31eb4 dfda9d8c dfda9d58 81492ac0 814a40d0 40946400 00000000 9d60: dfda9d7c 20000440 84600840 b5403587 40946400 00000000 00000003 854b3d40 9d80: dfda9e4c dfda9d90 8148e2c4 814929c4 35353238 00000000 00000000 00000000 9da0: 00000000 00000020 00000000 00000003 00000004 00000006 0800afa3 00000000 9dc0: 00000004 00005859 00000002 00000007 00000009 ffffffff 00000009 00000006 9de0: 00000002 00006f48 00000004 00000004 0000000a 00000200 0000caa2 00001003 9e00: 00007fff 02000003 00000e69 00000002 00000004 00004086 00000000 000006f1 9e20: 00000000 e42f69ca 00000000 868ac980 84600840 20000440 40946400 00000000 9e40: dfda9f14 dfda9e50 8148f5ec 8148e204 00000000 e42f69ca 00000000 00000000 9e60: 8254c844 dfda9ea4 0000005f 84972b68 00000064 84600870 dfda9ee4 dfda9e88 9e80: 80807dc4 807fe47c 00000064 00000001 00000000 dfda9ea4 838b3b10 83438660 9ea0: 00006400 0000000b dfda9e98 00000000 00000000 e42f69ca 00000000 868ac980 9ec0: 40946400 20000440 20000440 868ac980 00000003 854b3d40 dfda9ef4 dfda9ee8 9ee0: 80807ef8 e42f69ca dfda9f14 00000000 868ac981 40946400 20000440 868ac980 9f00: 00000003 854b3d40 dfda9fa4 dfda9f18 805bc574 8148f2a4 ecac8b10 854b3d40 9f20: dfda9f3c dfda9f30 81b65280 81b6514c dfda9f54 dfda9f40 8025b7a8 8028f458 9f40: dfda9fb0 40000000 dfda9f84 dfda9f58 80221bdc 8025b764 00000000 82a1eb0c 9f60: dfda9fb0 0013eb70 ecac8b10 80221b30 00000000 e42f69ca dfda9fac 00000000 9f80: 00000000 00356310 00000036 8020029c 854b3d40 00000036 00000000 dfda9fa8 9fa0: 80200060 805bc33c 00000000 00000000 00000003 40946400 20000440 00000000 9fc0: 00000000 00000000 00356310 00000036 003562d8 00000000 00000001 76f1a0dc 9fe0: 76f19e88 76f19e78 00018fa0 001309d0 60000010 00000003 00000000 00000000 Call trace: [<814a3e94>] (subdev_8255_io) from [<814a3bd0>] (subdev_8255_do_config+0x58/0x60 drivers/comedi/drivers/comedi_8255.c:115) r7:00000000 r6:84600840 r5:00000020 r4:814a3e94 [<814a3b78>] (subdev_8255_do_config) from [<814a3f88>] (__subdev_8255_init drivers/comedi/drivers/comedi_8255.c:172 [inline]) [<814a3b78>] (subdev_8255_do_config) from [<814a3f88>] (subdev_8255_io_init+0x88/0x98 drivers/comedi/drivers/comedi_8255.c:192) r4:87188b40 [<814a3f00>] (subdev_8255_io_init) from [<814a4138>] (dev_8255_attach drivers/comedi/drivers/8255.c:84 [inline]) [<814a3f00>] (subdev_8255_io_init) from [<814a4138>] (dev_8255_attach+0x74/0x138 drivers/comedi/drivers/8255.c:46) r7:00000000 r6:87188b40 r5:00000000 r4:84600840 [<814a40c4>] (dev_8255_attach) from [<81492ac0>] (comedi_device_attach+0x108/0x244 drivers/comedi/drivers.c:1101) r10:82d31eb4 r9:00000000 r8:84600840 r7:dfda9d90 r6:00000000 r5:84600840 r4:82bd9a60 [<814929b8>] (comedi_device_attach) from [<8148e2c4>] (do_devconfig_ioctl+0xcc/0x218 drivers/comedi/comedi_fops.c:930) r10:854b3d40 r9:00000003 r8:00000000 r7:40946400 r6:b5403587 r5:84600840 r4:20000440 [<8148e1f8>] (do_devconfig_ioctl) from [<8148f5ec>] (comedi_unlocked_ioctl+0x354/0x1db8 drivers/comedi/comedi_fops.c:2302) r8:00000000 r7:40946400 r6:20000440 r5:84600840 r4:868ac980 [<8148f298>] (comedi_unlocked_ioctl) from [<805bc574>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<8148f298>] (comedi_unlocked_ioctl) from [<805bc574>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<8148f298>] (comedi_unlocked_ioctl) from [<805bc574>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<8148f298>] (comedi_unlocked_ioctl) from [<805bc574>] (sys_ioctl+0x244/0xb5c fs/ioctl.c:583) r10:854b3d40 r9:00000003 r8:868ac980 r7:20000440 r6:40946400 r5:868ac981 r4:00000000 [<805bc330>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfda9fa8 to 0xdfda9ff0) 9fa0: 00000000 00000000 00000003 40946400 20000440 00000000 9fc0: 00000000 00000000 00356310 00000036 003562d8 00000000 00000001 76f1a0dc 9fe0: 76f19e88 76f19e78 00018fa0 001309d0 r10:00000036 r9:854b3d40 r8:8020029c r7:00000036 r6:00356310 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