8<--- cut here --- Unable to handle kernel paging request at virtual address fee08004 when write [fee08004] *pgd=80000080007003, *pmd=00000000 Internal error: Oops: a06 [#1] SMP ARM Modules linked in: CPU: 0 UID: 0 PID: 23853 Comm: syz.5.4554 Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP 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 : [<814108d0>] lr : [<814108bc>] psr: 60000013 sp : e42edcb8 ip : e42edcb8 fp : e42edcd4 r10: 00000000 r9 : 00000084 r8 : e42edda4 r7 : 00008001 r6 : 0000009b r5 : 844abd80 r4 : 00008004 r3 : 0000009b r2 : fee08004 r1 : 00000001 r0 : 844abd80 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 84c46440 DAC: fffffffd Register r0 information: slab kmalloc-192 start 844abd80 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 844abd80 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 0xe42ec000 allocated at kernel_clone+0xac/0x3f4 kernel/fork.c:2654 Register r9 information: non-paged memory Register r10 information: NULL pointer Register r11 information: 2-page vmalloc region starting at 0xe42ec000 allocated at kernel_clone+0xac/0x3f4 kernel/fork.c:2654 Register r12 information: 2-page vmalloc region starting at 0xe42ec000 allocated at kernel_clone+0xac/0x3f4 kernel/fork.c:2654 Process syz.5.4554 (pid: 23853, stack limit = 0xe42ec000) Stack: (0xe42edcb8 to 0xe42ee000) dca0: 81410870 00008001 dcc0: 844abd80 00008001 e42edcf4 e42edcd8 814105ac 8141087c 00008001 805158c0 dce0: 86ba4000 86ba4000 e42edd14 e42edcf8 81410964 81410560 844abd80 00000000 dd00: 86ba4000 00008001 e42edd54 e42edd18 81410b14 814108e8 e42edd3c e42edd28 dd20: 81aad768 00000000 813fae2c 829d5104 844abd80 00000000 e42edd90 844abd80 dd40: 00000000 82b29b30 e42edd8c e42edd58 813ff500 81410aac b5403587 00000000 dd60: 864b8c00 200000c0 844abd80 b5403587 40946400 864b8c00 00000003 844abdb0 dd80: e42ede4c e42edd90 813fae38 813ff400 35353238 00000000 00000000 00000000 dda0: 00000000 00008001 00000c09 00000001 00000400 00000001 00000001 00000004 ddc0: 00000004 0000005c 000000fd 00001002 00000008 0000000b 00000800 00000006 dde0: ffffffff 00000007 00000400 00000002 40000003 00000089 00000002 00000f27 de00: 00000004 00000007 10000008 0000000f 00000007 00000004 0000fffe fffffff8 de20: 00000000 fc68ac2c 00000000 84c07a80 844abd80 200000c0 40946400 864b8c00 de40: e42edf14 e42ede50 813fb9b8 813fad70 00000000 fc68ac2c 00000000 00000000 de60: 824b157c e42edea4 0000005f 84078c28 00000064 844c3e64 e42edee4 e42ede88 de80: 807b48ac 807aac84 00000064 00000001 00000000 e42edea4 85f14b50 8342ff68 dea0: 00006400 0000000b e42ede98 00000000 00000000 fc68ac2c 00000000 84c07a80 dec0: 40946400 200000c0 200000c0 84c07a80 00000003 864b8c00 e42edef4 e42edee8 dee0: 807b49dc fc68ac2c e42edf14 00000000 84c07a81 40946400 200000c0 84c07a80 df00: 00000003 864b8c00 e42edfa4 e42edf18 805815f4 813fb8c0 ecac8b10 864b8c00 df20: e42edf3c e42edf30 81aa9498 81aa9364 e42edf54 e42edf40 8025bb3c 8028f148 df40: e42edfb0 40000000 e42edf84 e42edf58 80221a4c 8025baf8 00000000 8281d0bc df60: e42edfb0 0013ddc0 ecac8b10 802219a0 00000000 fc68ac2c e42edfac 00000000 df80: 00000000 00346310 00000036 8020029c 864b8c00 00000036 00000000 e42edfa8 dfa0: 80200060 805813bc 00000000 00000000 00000003 40946400 200000c0 00000000 dfc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76f410dc dfe0: 76f40e88 76f40e78 00018734 0012fc20 60000010 00000003 00000000 00000000 Call trace: [<81410870>] (subdev_8255_io) from [<814105ac>] (subdev_8255_do_config+0x58/0x60 drivers/comedi/drivers/comedi_8255.c:115) r7:00008001 r6:844abd80 r5:00008001 r4:81410870 [<81410554>] (subdev_8255_do_config) from [<81410964>] (__subdev_8255_init drivers/comedi/drivers/comedi_8255.c:172 [inline]) [<81410554>] (subdev_8255_do_config) from [<81410964>] (subdev_8255_io_init+0x88/0x98 drivers/comedi/drivers/comedi_8255.c:192) r4:86ba4000 [<814108dc>] (subdev_8255_io_init) from [<81410b14>] (dev_8255_attach drivers/comedi/drivers/8255.c:82 [inline]) [<814108dc>] (subdev_8255_io_init) from [<81410b14>] (dev_8255_attach+0x74/0x120 drivers/comedi/drivers/8255.c:46) r7:00008001 r6:86ba4000 r5:00000000 r4:844abd80 [<81410aa0>] (dev_8255_attach) from [<813ff500>] (comedi_device_attach+0x10c/0x248 drivers/comedi/drivers.c:1069) r10:82b29b30 r9:00000000 r8:844abd80 r7:e42edd90 r6:00000000 r5:844abd80 r4:829d5104 [<813ff3f4>] (comedi_device_attach) from [<813fae38>] (do_devconfig_ioctl+0xd4/0x21c drivers/comedi/comedi_fops.c:928) r10:844abdb0 r9:00000003 r8:864b8c00 r7:40946400 r6:b5403587 r5:844abd80 r4:200000c0 [<813fad64>] (do_devconfig_ioctl) from [<813fb9b8>] (comedi_unlocked_ioctl+0x104/0x1c80 drivers/comedi/comedi_fops.c:2240) r8:864b8c00 r7:40946400 r6:200000c0 r5:844abd80 r4:84c07a80 [<813fb8b4>] (comedi_unlocked_ioctl) from [<805815f4>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<813fb8b4>] (comedi_unlocked_ioctl) from [<805815f4>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<813fb8b4>] (comedi_unlocked_ioctl) from [<805815f4>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<813fb8b4>] (comedi_unlocked_ioctl) from [<805815f4>] (sys_ioctl+0x244/0xb5c fs/ioctl.c:583) r10:864b8c00 r9:00000003 r8:84c07a80 r7:200000c0 r6:40946400 r5:84c07a81 r4:00000000 [<805813b0>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xe42edfa8 to 0xe42edff0) dfa0: 00000000 00000000 00000003 40946400 200000c0 00000000 dfc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76f410dc dfe0: 76f40e88 76f40e78 00018734 0012fc20 r10:00000036 r9:864b8c00 r8:8020029c r7:00000036 r6:00346310 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