8<--- cut here --- Unable to handle kernel paging request at virtual address fee04f2c when write [fee04f2c] *pgd=80000080007003, *pmd=00000000 Internal error: Oops: a06 [#1] SMP ARM Modules linked in: CPU: 0 UID: 0 PID: 23478 Comm: syz.4.7801 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 : [<814161dc>] lr : [<814161c8>] psr: 60000013 sp : e02f1cb0 ip : e02f1cb0 fp : e02f1ccc r10: 00000001 r9 : 00000084 r8 : e02f1d9c r7 : 00004f29 r6 : 0000009b r5 : 838796c0 r4 : 00004f2c r3 : 0000009b r2 : fee04f2c r1 : 00000001 r0 : 838796c0 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 86ce4100 DAC: fffffffd Register r0 information: slab kmalloc-192 start 838796c0 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 838796c0 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 0xe02f0000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2651 Register r9 information: non-paged memory Register r10 information: non-paged memory Register r11 information: 2-page vmalloc region starting at 0xe02f0000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2651 Register r12 information: 2-page vmalloc region starting at 0xe02f0000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2651 Process syz.4.7801 (pid: 23478, stack limit = 0xe02f0000) Stack: (0xe02f1cb0 to 0xe02f2000) 1ca0: 8141617c 838796c0 00004f29 00004f29 1cc0: e02f1cec e02f1cd0 81415eb4 81416188 00004f29 805150ac 85e94000 85e94000 1ce0: e02f1d0c e02f1cf0 81416274 81415e68 838796c0 00000000 85e94000 00004f29 1d00: e02f1d4c e02f1d10 81416420 814161f4 0000005f 8385e080 828217b0 00000000 1d20: 00000000 829d46a0 838796c0 83879704 e02f1d88 838796c0 00000000 82b28ad8 1d40: e02f1d84 e02f1d50 81404f54 814163b8 838796f0 00000000 e02f1d74 200000c0 1d60: 838796c0 b5403587 838796f0 851b2400 40946400 00000003 e02f1e44 e02f1d88 1d80: 814008ac 81404e58 35353238 00000000 00000000 00000000 00000000 00004f29 1da0: 00000005 00000003 00000004 00000001 00000003 00000012 00000011 00000081 1dc0: fffffffc 00000002 fffffffe 00000001 00000001 00000002 00000101 00000008 1de0: 00400009 00000003 00000005 00000099 0000caa7 00000080 00000204 00000007 1e00: 02000e67 0000003c 00000008 fffffffe 00000000 fffffff4 00000000 99696256 1e20: 00000000 85b8e000 838796c0 200000c0 838796f0 851b2400 e02f1f14 e02f1e48 1e40: 814018a0 814007b8 00000000 00000000 00000000 e02f1e54 e02f1e54 99696256 1e60: 00000000 00000000 824a45ec 0000005f 84547600 00000064 838b3e64 851b2400 1e80: e02f1ee4 e02f1e90 807b8180 807ae6a4 00000064 00000001 00000000 e02f1eac 1ea0: 833dec10 834d5330 00006400 0000000b e02f1ea0 00000000 e02f1d40 99696256 1ec0: 85b8e000 40946400 200000c0 200000c0 85b8e000 00000003 e02f1ef4 e02f1ee8 1ee0: 807b82a0 99696256 e02f1f14 40946400 00000000 85b8e001 200000c0 85b8e000 1f00: 00000003 851b2400 e02f1fa4 e02f1f18 80585768 814012f0 ecac8b10 851b2400 1f20: e02f1f3c e02f1f30 81ab004c 81aaff1c e02f1f54 e02f1f40 8025bcbc 8028e0c4 1f40: e02f1fb0 40000000 e02f1f84 e02f1f58 80221a38 8025bc78 00000000 8281d17c 1f60: e02f1fb0 0014c8c0 ecac8b10 8022198c 00000000 99696256 e02f1fac 00000000 1f80: 00000000 00326310 00000036 8020029c 851b2400 00000036 00000000 e02f1fa8 1fa0: 80200060 80585644 00000000 00000000 00000003 40946400 200000c0 00000000 1fc0: 00000000 00000000 00326310 00000036 00310000 00000000 00006364 76fb80bc 1fe0: 76fb7ec0 76fb7eb0 000192bc 00132360 60000010 00000003 00000000 00000000 Call trace: [<8141617c>] (subdev_8255_io) from [<81415eb4>] (subdev_8255_do_config+0x58/0x60 drivers/comedi/drivers/comedi_8255.c:115) r7:00004f29 r6:00004f29 r5:838796c0 r4:8141617c [<81415e5c>] (subdev_8255_do_config) from [<81416274>] (__subdev_8255_init drivers/comedi/drivers/comedi_8255.c:172 [inline]) [<81415e5c>] (subdev_8255_do_config) from [<81416274>] (subdev_8255_io_init+0x8c/0x9c drivers/comedi/drivers/comedi_8255.c:192) r4:85e94000 [<814161e8>] (subdev_8255_io_init) from [<81416420>] (dev_8255_attach drivers/comedi/drivers/8255.c:82 [inline]) [<814161e8>] (subdev_8255_io_init) from [<81416420>] (dev_8255_attach+0x74/0x120 drivers/comedi/drivers/8255.c:46) r7:00004f29 r6:85e94000 r5:00000000 r4:838796c0 [<814163ac>] (dev_8255_attach) from [<81404f54>] (comedi_device_attach+0x108/0x250 drivers/comedi/drivers.c:1069) r10:82b28ad8 r9:00000000 r8:838796c0 r7:e02f1d88 r6:83879704 r5:838796c0 r4:829d46a0 [<81404e4c>] (comedi_device_attach) from [<814008ac>] (do_devconfig_ioctl+0x100/0x220 drivers/comedi/comedi_fops.c:928) r10:00000003 r9:40946400 r8:851b2400 r7:838796f0 r6:b5403587 r5:838796c0 r4:200000c0 [<814007ac>] (do_devconfig_ioctl) from [<814018a0>] (comedi_unlocked_ioctl+0x5bc/0x1c2c drivers/comedi/comedi_fops.c:2240) r8:851b2400 r7:838796f0 r6:200000c0 r5:838796c0 r4:85b8e000 [<814012e4>] (comedi_unlocked_ioctl) from [<80585768>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<814012e4>] (comedi_unlocked_ioctl) from [<80585768>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<814012e4>] (comedi_unlocked_ioctl) from [<80585768>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<814012e4>] (comedi_unlocked_ioctl) from [<80585768>] (sys_ioctl+0x130/0xba0 fs/ioctl.c:583) r10:851b2400 r9:00000003 r8:85b8e000 r7:200000c0 r6:85b8e001 r5:00000000 r4:40946400 [<80585638>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xe02f1fa8 to 0xe02f1ff0) 1fa0: 00000000 00000000 00000003 40946400 200000c0 00000000 1fc0: 00000000 00000000 00326310 00000036 00310000 00000000 00006364 76fb80bc 1fe0: 76fb7ec0 76fb7eb0 000192bc 00132360 r10:00000036 r9:851b2400 r8:8020029c r7:00000036 r6:00326310 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