8<--- cut here --- Unable to handle kernel paging request at virtual address fee00143 when write [fee00143] *pgd=80000080007003, *pmd=00000000 Internal error: Oops: a06 [#1] SMP ARM Modules linked in: CPU: 1 UID: 0 PID: 13198 Comm: syz.4.2399 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 : [<814a3db4>] lr : [<814a3da0>] psr: 60000013 sp : e43fdcb8 ip : e43fdcb8 fp : e43fdcd4 r10: 00000140 r9 : 00000004 r8 : e43fdda4 r7 : 00000000 r6 : 0000009b r5 : 8311b540 r4 : 00000143 r3 : 0000009b r2 : fee00143 r1 : 00000001 r0 : 8311b540 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 86aa2900 DAC: 00000000 Register r0 information: slab kmalloc-192 start 8311b540 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 8311b540 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 0xe43fc000 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 0xe43fc000 allocated at kernel_clone+0xc4/0x43c kernel/fork.c:2748 Register r12 information: 2-page vmalloc region starting at 0xe43fc000 allocated at kernel_clone+0xc4/0x43c kernel/fork.c:2748 Process syz.4.2399 (pid: 13198, stack limit = 0xe43fc000) Stack: (0xe43fdcb8 to 0xe43fe000) dca0: 814a3d54 00000140 dcc0: 8311b540 00000000 e43fdcf4 e43fdcd8 814a3a90 814a3d60 00000140 80547708 dce0: 866ef000 866ef000 e43fdd14 e43fdcf8 814a3e48 814a3a44 8311b540 00000000 dd00: 866ef000 00000000 e43fdd54 e43fdd18 814a3ff8 814a3dcc ffffffff 00000004 dd20: 82a22dc0 00000000 00000000 82bd9660 8311b540 00000000 e43fdd90 8311b540 dd40: 00000000 82d30eb4 e43fdd8c e43fdd58 81492980 814a3f90 40946400 00000000 dd60: e43fdd7c 200000c0 8311b540 b5403587 40946400 00000001 00000003 866d6e40 dd80: e43fde4c e43fdd90 8148e184 81492884 35353238 00000000 00000000 00000000 dda0: 00000000 00000140 00000020 00000009 00000002 00000400 00000001 00007fff ddc0: 30000002 00000007 0000c72d 00000000 00000007 00000003 00000008 00000029 dde0: 000072f0 00000101 00000006 00000006 00000401 00000004 00000006 0000a2d8 de00: 00000009 00001000 00000008 0000000a ffffffff 00000383 00008001 00000004 de20: 00000000 0def426a 00000000 8387aa80 8311b540 200000c0 40946400 00000001 de40: e43fdf14 e43fde50 8148f4ac 8148e0c4 00000000 0def426a 00000000 00000000 de60: 8254a844 e43fdea4 0000005f 848fd678 00000064 8311b570 e43fdee4 e43fde88 de80: 80807df4 807fe4ac 00000064 00000001 00000000 e43fdea4 83ff0d10 834e4550 dea0: 00006400 0000000b e43fde98 00000000 00000000 0def426a 00000000 8387aa80 dec0: 40946400 200000c0 200000c0 8387aa80 00000003 866d6e40 e43fdef4 e43fdee8 dee0: 80807f28 0def426a e43fdf14 00000000 8387aa81 40946400 200000c0 8387aa80 df00: 00000003 866d6e40 e43fdfa4 e43fdf18 805bc58c 8148f164 ecac8b10 866d6e40 df20: e43fdf3c e43fdf30 81b5e580 81b5e44c e43fdf54 e43fdf40 8025b7a8 8028f490 df40: e43fdfb0 40000000 e43fdf84 e43fdf58 80221bdc 8025b764 00000000 82a1eb0c df60: e43fdfb0 0013eb70 ecac8b10 80221b30 00000000 0def426a e43fdfac 00000000 df80: 00000000 00356310 00000036 8020029c 866d6e40 00000036 00000000 e43fdfa8 dfa0: 80200060 805bc354 00000000 00000000 00000003 40946400 200000c0 00000000 dfc0: 00000000 00000000 00356310 00000036 003562d8 00000000 00000001 76fab0dc dfe0: 76faae88 76faae78 00018fa0 001309d0 60000010 00000003 00000000 00000000 Call trace: [<814a3d54>] (subdev_8255_io) from [<814a3a90>] (subdev_8255_do_config+0x58/0x60 drivers/comedi/drivers/comedi_8255.c:115) r7:00000000 r6:8311b540 r5:00000140 r4:814a3d54 [<814a3a38>] (subdev_8255_do_config) from [<814a3e48>] (__subdev_8255_init drivers/comedi/drivers/comedi_8255.c:172 [inline]) [<814a3a38>] (subdev_8255_do_config) from [<814a3e48>] (subdev_8255_io_init+0x88/0x98 drivers/comedi/drivers/comedi_8255.c:192) r4:866ef000 [<814a3dc0>] (subdev_8255_io_init) from [<814a3ff8>] (dev_8255_attach drivers/comedi/drivers/8255.c:84 [inline]) [<814a3dc0>] (subdev_8255_io_init) from [<814a3ff8>] (dev_8255_attach+0x74/0x138 drivers/comedi/drivers/8255.c:46) r7:00000000 r6:866ef000 r5:00000000 r4:8311b540 [<814a3f84>] (dev_8255_attach) from [<81492980>] (comedi_device_attach+0x108/0x244 drivers/comedi/drivers.c:1101) r10:82d30eb4 r9:00000000 r8:8311b540 r7:e43fdd90 r6:00000000 r5:8311b540 r4:82bd9660 [<81492878>] (comedi_device_attach) from [<8148e184>] (do_devconfig_ioctl+0xcc/0x218 drivers/comedi/comedi_fops.c:930) r10:866d6e40 r9:00000003 r8:00000001 r7:40946400 r6:b5403587 r5:8311b540 r4:200000c0 [<8148e0b8>] (do_devconfig_ioctl) from [<8148f4ac>] (comedi_unlocked_ioctl+0x354/0x1db8 drivers/comedi/comedi_fops.c:2302) r8:00000001 r7:40946400 r6:200000c0 r5:8311b540 r4:8387aa80 [<8148f158>] (comedi_unlocked_ioctl) from [<805bc58c>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<8148f158>] (comedi_unlocked_ioctl) from [<805bc58c>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<8148f158>] (comedi_unlocked_ioctl) from [<805bc58c>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<8148f158>] (comedi_unlocked_ioctl) from [<805bc58c>] (sys_ioctl+0x244/0xb5c fs/ioctl.c:583) r10:866d6e40 r9:00000003 r8:8387aa80 r7:200000c0 r6:40946400 r5:8387aa81 r4:00000000 [<805bc348>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xe43fdfa8 to 0xe43fdff0) dfa0: 00000000 00000000 00000003 40946400 200000c0 00000000 dfc0: 00000000 00000000 00356310 00000036 003562d8 00000000 00000001 76fab0dc dfe0: 76faae88 76faae78 00018fa0 001309d0 r10:00000036 r9:866d6e40 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