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: 1 UID: 0 PID: 10327 Comm: syz.4.1690 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 : [<8140e660>] lr : [<8140e64c>] psr: 60000013 sp : dfa9dcb8 ip : dfa9dcb8 fp : dfa9dcd4 r10: 00000000 r9 : 00000084 r8 : dfa9dda4 r7 : 00008001 r6 : 0000009b r5 : 843fec00 r4 : 00008004 r3 : 0000009b r2 : fee08004 r1 : 00000001 r0 : 843fec00 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 85f93f00 DAC: 00000000 Register r0 information: slab kmalloc-192 start 843fec00 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 843fec00 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 0xdfa9c000 allocated at kernel_clone+0xac/0x3f4 kernel/fork.c:2651 Register r9 information: non-paged memory Register r10 information: NULL pointer Register r11 information: 2-page vmalloc region starting at 0xdfa9c000 allocated at kernel_clone+0xac/0x3f4 kernel/fork.c:2651 Register r12 information: 2-page vmalloc region starting at 0xdfa9c000 allocated at kernel_clone+0xac/0x3f4 kernel/fork.c:2651 Process syz.4.1690 (pid: 10327, stack limit = 0xdfa9c000) Stack: (0xdfa9dcb8 to 0xdfa9e000) dca0: 8140e600 00008001 dcc0: 843fec00 00008001 dfa9dcf4 dfa9dcd8 8140e33c 8140e60c 00008001 80516350 dce0: 83930000 83930000 dfa9dd14 dfa9dcf8 8140e6f4 8140e2f0 843fec00 00000000 dd00: 83930000 00008001 dfa9dd54 dfa9dd18 8140e8a4 8140e678 00000015 8affb200 dd20: 828215f0 00000000 00000000 829d4c84 843fec00 00000000 dfa9dd90 843fec00 dd40: 00000000 82b29b30 dfa9dd8c dfa9dd58 813fd298 8140e83c 40946400 00000000 dd60: dfa9dd7c 200000c0 843fec00 b5403587 40946400 8af40000 00000003 843fec30 dd80: dfa9de4c dfa9dd90 813f8bd0 813fd198 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 6a550908 00000000 85d7e180 843fec00 200000c0 40946400 8af40000 de40: dfa9df14 dfa9de50 813f9750 813f8b08 00000000 6a550908 00000000 00000000 de60: 824b1574 dfa9dea4 0000005f 84080838 00000064 845fcc6c dfa9dee4 dfa9de88 de80: 807b43fc 807aaa78 00000064 00000001 00000000 dfa9dea4 8607e6d0 834ec440 dea0: 00006400 0000000b dfa9de98 00000000 00000000 6a550908 00000000 85d7e180 dec0: 40946400 200000c0 200000c0 85d7e180 00000003 8af40000 dfa9def4 dfa9dee8 dee0: 807b452c 6a550908 dfa9df14 00000000 85d7e181 40946400 200000c0 85d7e180 df00: 00000003 8af40000 dfa9dfa4 dfa9df18 80582358 813f9658 ecac8b10 8af40000 df20: dfa9df3c dfa9df30 81aa745c 81aa732c dfa9df54 dfa9df40 8025ba7c 8028ef68 df40: dfa9dfb0 40000000 dfa9df84 dfa9df58 80221a54 8025ba38 00000000 8281cfbc df60: dfa9dfb0 0013ddc0 ecac8b10 802219a8 00000000 6a550908 dfa9dfac 00000000 df80: 00000000 00346310 00000036 8020029c 8af40000 00000036 00000000 dfa9dfa8 dfa0: 80200060 80582120 00000000 00000000 00000003 40946400 200000c0 00000000 dfc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76fda0dc dfe0: 76fd9e88 76fd9e78 00018734 0012fc20 60000010 00000003 00000000 00000000 Call trace: [<8140e600>] (subdev_8255_io) from [<8140e33c>] (subdev_8255_do_config+0x58/0x60 drivers/comedi/drivers/comedi_8255.c:115) r7:00008001 r6:843fec00 r5:00008001 r4:8140e600 [<8140e2e4>] (subdev_8255_do_config) from [<8140e6f4>] (__subdev_8255_init drivers/comedi/drivers/comedi_8255.c:172 [inline]) [<8140e2e4>] (subdev_8255_do_config) from [<8140e6f4>] (subdev_8255_io_init+0x88/0x98 drivers/comedi/drivers/comedi_8255.c:192) r4:83930000 [<8140e66c>] (subdev_8255_io_init) from [<8140e8a4>] (dev_8255_attach drivers/comedi/drivers/8255.c:82 [inline]) [<8140e66c>] (subdev_8255_io_init) from [<8140e8a4>] (dev_8255_attach+0x74/0x120 drivers/comedi/drivers/8255.c:46) r7:00008001 r6:83930000 r5:00000000 r4:843fec00 [<8140e830>] (dev_8255_attach) from [<813fd298>] (comedi_device_attach+0x10c/0x248 drivers/comedi/drivers.c:1069) r10:82b29b30 r9:00000000 r8:843fec00 r7:dfa9dd90 r6:00000000 r5:843fec00 r4:829d4c84 [<813fd18c>] (comedi_device_attach) from [<813f8bd0>] (do_devconfig_ioctl+0xd4/0x21c drivers/comedi/comedi_fops.c:928) r10:843fec30 r9:00000003 r8:8af40000 r7:40946400 r6:b5403587 r5:843fec00 r4:200000c0 [<813f8afc>] (do_devconfig_ioctl) from [<813f9750>] (comedi_unlocked_ioctl+0x104/0x1c80 drivers/comedi/comedi_fops.c:2240) r8:8af40000 r7:40946400 r6:200000c0 r5:843fec00 r4:85d7e180 [<813f964c>] (comedi_unlocked_ioctl) from [<80582358>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<813f964c>] (comedi_unlocked_ioctl) from [<80582358>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<813f964c>] (comedi_unlocked_ioctl) from [<80582358>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<813f964c>] (comedi_unlocked_ioctl) from [<80582358>] (sys_ioctl+0x244/0xb58 fs/ioctl.c:583) r10:8af40000 r9:00000003 r8:85d7e180 r7:200000c0 r6:40946400 r5:85d7e181 r4:00000000 [<80582114>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfa9dfa8 to 0xdfa9dff0) dfa0: 00000000 00000000 00000003 40946400 200000c0 00000000 dfc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76fda0dc dfe0: 76fd9e88 76fd9e78 00018734 0012fc20 r10:00000036 r9:8af40000 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