8<--- cut here --- Unable to handle kernel paging request at virtual address fee00403 when write [fee00403] *pgd=80000080007003, *pmd=00000000 Internal error: Oops: a06 [#1] SMP ARM Modules linked in: CPU: 1 UID: 0 PID: 12332 Comm: syz.0.1679 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 : [<814409a0>] lr : [<8144098c>] psr: 60000013 sp : dfc25cb8 ip : dfc25cb8 fp : dfc25cd4 r10: 00000000 r9 : 00000084 r8 : dfc25da4 r7 : 00000400 r6 : 0000009b r5 : 84649240 r4 : 00000403 r3 : 0000009b r2 : fee00403 r1 : 00000001 r0 : 84649240 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 85c51600 DAC: 00000000 Register r0 information: slab kmalloc-192 start 84649240 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 84649240 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 0xdfc24000 allocated at kernel_clone+0xac/0x428 kernel/fork.c:2654 Register r9 information: non-paged memory Register r10 information: NULL pointer Register r11 information: 2-page vmalloc region starting at 0xdfc24000 allocated at kernel_clone+0xac/0x428 kernel/fork.c:2654 Register r12 information: 2-page vmalloc region starting at 0xdfc24000 allocated at kernel_clone+0xac/0x428 kernel/fork.c:2654 Process syz.0.1679 (pid: 12332, stack limit = 0xdfc24000) Stack: (0xdfc25cb8 to 0xdfc26000) 5ca0: 81440940 00000400 5cc0: 84649240 00000400 dfc25cf4 dfc25cd8 8144067c 8144094c 00000400 805234b4 5ce0: 85e3fd80 85e3fd80 dfc25d14 dfc25cf8 81440a34 81440630 84649240 00000000 5d00: 85e3fd80 00000400 dfc25d54 dfc25d18 81440be4 814409b8 82afe40c 8391de00 5d20: 828217c0 00000000 00000000 829d6ec4 84649240 00000000 dfc25d90 84649240 5d40: 00000000 82b2f064 dfc25d8c dfc25d58 8142f52c 81440b7c 40946400 00000000 5d60: dfc25d7c 20000440 84649240 b5403587 40946400 00000001 00000003 8457c800 5d80: dfc25e4c dfc25d90 8142ad38 8142f42c 35353238 00000000 00000000 00000000 5da0: 00000000 00000400 00000000 00000a1a 00000004 00000006 0800afa3 00000000 5dc0: 00000004 00000002 00000007 00000007 00000009 00000001 00000009 00000006 5de0: 00000002 00006f48 00000004 00000002 0000000a 00000006 0000caa2 20001003 5e00: 20001e5b 02000003 00000e69 00000002 00006871 00004086 00000000 000006f5 5e20: 00000000 b5019f7f 00000000 83e64e40 84649240 20000440 40946400 00000001 5e40: dfc25f14 dfc25e50 8142c05c 8142ac70 00000000 b5019f7f 00000000 00000000 5e60: 824b857c dfc25ea4 0000005f 842d4448 00000064 84649270 dfc25ee4 dfc25e88 5e80: 807cf200 807c55d8 00000064 00000001 00000000 dfc25ea4 8338f6d0 834f3330 5ea0: 00006400 0000000b dfc25e98 00000000 00000000 b5019f7f 00000000 83e64e40 5ec0: 40946400 20000440 20000440 83e64e40 00000003 8457c800 dfc25ef4 dfc25ee8 5ee0: 807cf330 b5019f7f dfc25f14 00000000 83e64e41 40946400 20000440 83e64e40 5f00: 00000003 8457c800 dfc25fa4 dfc25f18 805906a8 8142bd14 ecac8b10 8457c800 5f20: dfc25f3c dfc25f30 81ae4734 81ae4600 dfc25f54 dfc25f40 8025a824 8028c290 5f40: dfc25fb0 40000000 dfc25f84 dfc25f58 80220bf8 8025a7e0 00000000 8281d2bc 5f60: dfc25fb0 0013e480 ecac8b10 80220b4c 00000000 b5019f7f dfc25fac 00000000 5f80: 00000000 00346310 00000036 8020029c 8457c800 00000036 00000000 dfc25fa8 5fa0: 80200060 80590470 00000000 00000000 00000003 40946400 20000440 00000000 5fc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76f260dc 5fe0: 76f25e88 76f25e78 00018ba0 001302e0 60000010 00000003 00000000 00000000 Call trace: [<81440940>] (subdev_8255_io) from [<8144067c>] (subdev_8255_do_config+0x58/0x60 drivers/comedi/drivers/comedi_8255.c:115) r7:00000400 r6:84649240 r5:00000400 r4:81440940 [<81440624>] (subdev_8255_do_config) from [<81440a34>] (__subdev_8255_init drivers/comedi/drivers/comedi_8255.c:172 [inline]) [<81440624>] (subdev_8255_do_config) from [<81440a34>] (subdev_8255_io_init+0x88/0x98 drivers/comedi/drivers/comedi_8255.c:192) r4:85e3fd80 [<814409ac>] (subdev_8255_io_init) from [<81440be4>] (dev_8255_attach drivers/comedi/drivers/8255.c:82 [inline]) [<814409ac>] (subdev_8255_io_init) from [<81440be4>] (dev_8255_attach+0x74/0x120 drivers/comedi/drivers/8255.c:46) r7:00000400 r6:85e3fd80 r5:00000000 r4:84649240 [<81440b70>] (dev_8255_attach) from [<8142f52c>] (comedi_device_attach+0x10c/0x248 drivers/comedi/drivers.c:1069) r10:82b2f064 r9:00000000 r8:84649240 r7:dfc25d90 r6:00000000 r5:84649240 r4:829d6ec4 [<8142f420>] (comedi_device_attach) from [<8142ad38>] (do_devconfig_ioctl+0xd4/0x21c drivers/comedi/comedi_fops.c:928) r10:8457c800 r9:00000003 r8:00000001 r7:40946400 r6:b5403587 r5:84649240 r4:20000440 [<8142ac64>] (do_devconfig_ioctl) from [<8142c05c>] (comedi_unlocked_ioctl+0x354/0x1dbc drivers/comedi/comedi_fops.c:2300) r8:00000001 r7:40946400 r6:20000440 r5:84649240 r4:83e64e40 [<8142bd08>] (comedi_unlocked_ioctl) from [<805906a8>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<8142bd08>] (comedi_unlocked_ioctl) from [<805906a8>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<8142bd08>] (comedi_unlocked_ioctl) from [<805906a8>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<8142bd08>] (comedi_unlocked_ioctl) from [<805906a8>] (sys_ioctl+0x244/0xb5c fs/ioctl.c:583) r10:8457c800 r9:00000003 r8:83e64e40 r7:20000440 r6:40946400 r5:83e64e41 r4:00000000 [<80590464>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfc25fa8 to 0xdfc25ff0) 5fa0: 00000000 00000000 00000003 40946400 20000440 00000000 5fc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76f260dc 5fe0: 76f25e88 76f25e78 00018ba0 001302e0 r10:00000036 r9:8457c800 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