8<--- cut here --- Unable to handle kernel paging request at virtual address fee04f2d when write [fee04f2d] *pgd=80000080007003, *pmd=00000000 Internal error: Oops: a06 [#1] SMP ARM Modules linked in: CPU: 0 UID: 0 PID: 4799 Comm: syz.2.193 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 : [<8143e108>] lr : [<8143e0f4>] psr: 60000013 sp : dfb4dcb8 ip : dfb4dcb8 fp : dfb4dcd4 r10: 00000000 r9 : 00000084 r8 : dfb4dda4 r7 : 00004f2a r6 : 0000009b r5 : 845ee600 r4 : 00004f2d r3 : 0000009b r2 : fee04f2d r1 : 00000001 r0 : 845ee600 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 860cb5c0 DAC: fffffffd Register r0 information: slab kmalloc-192 start 845ee600 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 845ee600 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 0xdfb4c000 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 0xdfb4c000 allocated at kernel_clone+0xac/0x428 kernel/fork.c:2654 Register r12 information: 2-page vmalloc region starting at 0xdfb4c000 allocated at kernel_clone+0xac/0x428 kernel/fork.c:2654 Process syz.2.193 (pid: 4799, stack limit = 0xdfb4c000) Stack: (0xdfb4dcb8 to 0xdfb4e000) dca0: 8143e0a8 00004f2a dcc0: 845ee600 00004f2a dfb4dcf4 dfb4dcd8 8143dde4 8143e0b4 00004f2a 80522730 dce0: 8530a800 8530a800 dfb4dd14 dfb4dcf8 8143e19c 8143dd98 845ee600 00000000 dd00: 8530a800 00004f2a dfb4dd54 dfb4dd18 8143e34c 8143e120 82b123ec 830e4f80 dd20: 828217c0 00000000 00000000 829d6e04 845ee600 00000000 dfb4dd90 845ee600 dd40: 00000000 82b2efdc dfb4dd8c dfb4dd58 8142cc90 8143e2e4 b5403587 00000000 dd60: 00000003 200000c0 845ee600 b5403587 40946400 00000003 00000003 84713c00 dd80: dfb4de4c dfb4dd90 8142849c 8142cb90 35353238 00000000 00000000 00000000 dda0: 00000000 00004f2a 000000d7 00010007 00000004 00001d02 00000001 00000085 ddc0: 00000005 00000081 00000003 00000002 fffffffe 00000001 80000001 00000000 dde0: 00000101 00000008 00400009 00000004 00000005 00000099 0000caa7 00000080 de00: 00000000 00000005 02000e67 00000002 00000008 00000008 00000000 fffbfff8 de20: 00000000 2453ef8d 00000000 85399c00 845ee600 200000c0 40946400 00000003 de40: dfb4df14 dfb4de50 814297c0 814283d4 00000000 2453ef8d 00000000 00000000 de60: 824b857c dfb4dea4 0000005f 847b2640 00000064 845ee630 dfb4dee4 dfb4de88 de80: 807cd86c 807c3c44 00000064 00000001 00000000 dfb4dea4 8337b490 834f2330 dea0: 00006400 0000000b dfb4de98 00000000 00000000 2453ef8d 00000000 85399c00 dec0: 40946400 200000c0 200000c0 85399c00 00000003 84713c00 dfb4def4 dfb4dee8 dee0: 807cd99c 2453ef8d dfb4df14 00000000 85399c01 40946400 200000c0 85399c00 df00: 00000003 84713c00 dfb4dfa4 dfb4df18 8058f8fc 81429478 ecac8b10 84713c00 df20: dfb4df3c dfb4df30 81ae1534 81ae1400 dfb4df54 dfb4df40 8025a85c 8028c358 df40: dfb4dfb0 40000000 dfb4df84 dfb4df58 80220bf8 8025a818 00000000 8281d2bc df60: dfb4dfb0 0013e290 ecac8b10 80220b4c 00000000 2453ef8d dfb4dfac 00000000 df80: 00000000 00346310 00000036 8020029c 84713c00 00000036 00000000 dfb4dfa8 dfa0: 80200060 8058f6c4 00000000 00000000 00000003 40946400 200000c0 00000000 dfc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76f430dc dfe0: 76f42e88 76f42e78 00018ba0 001300f0 60000010 00000003 00000000 00000000 Call trace: [<8143e0a8>] (subdev_8255_io) from [<8143dde4>] (subdev_8255_do_config+0x58/0x60 drivers/comedi/drivers/comedi_8255.c:115) r7:00004f2a r6:845ee600 r5:00004f2a r4:8143e0a8 [<8143dd8c>] (subdev_8255_do_config) from [<8143e19c>] (__subdev_8255_init drivers/comedi/drivers/comedi_8255.c:172 [inline]) [<8143dd8c>] (subdev_8255_do_config) from [<8143e19c>] (subdev_8255_io_init+0x88/0x98 drivers/comedi/drivers/comedi_8255.c:192) r4:8530a800 [<8143e114>] (subdev_8255_io_init) from [<8143e34c>] (dev_8255_attach drivers/comedi/drivers/8255.c:82 [inline]) [<8143e114>] (subdev_8255_io_init) from [<8143e34c>] (dev_8255_attach+0x74/0x120 drivers/comedi/drivers/8255.c:46) r7:00004f2a r6:8530a800 r5:00000000 r4:845ee600 [<8143e2d8>] (dev_8255_attach) from [<8142cc90>] (comedi_device_attach+0x10c/0x248 drivers/comedi/drivers.c:1069) r10:82b2efdc r9:00000000 r8:845ee600 r7:dfb4dd90 r6:00000000 r5:845ee600 r4:829d6e04 [<8142cb84>] (comedi_device_attach) from [<8142849c>] (do_devconfig_ioctl+0xd4/0x21c drivers/comedi/comedi_fops.c:928) r10:84713c00 r9:00000003 r8:00000003 r7:40946400 r6:b5403587 r5:845ee600 r4:200000c0 [<814283c8>] (do_devconfig_ioctl) from [<814297c0>] (comedi_unlocked_ioctl+0x354/0x1dbc drivers/comedi/comedi_fops.c:2300) r8:00000003 r7:40946400 r6:200000c0 r5:845ee600 r4:85399c00 [<8142946c>] (comedi_unlocked_ioctl) from [<8058f8fc>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<8142946c>] (comedi_unlocked_ioctl) from [<8058f8fc>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<8142946c>] (comedi_unlocked_ioctl) from [<8058f8fc>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<8142946c>] (comedi_unlocked_ioctl) from [<8058f8fc>] (sys_ioctl+0x244/0xb5c fs/ioctl.c:583) r10:84713c00 r9:00000003 r8:85399c00 r7:200000c0 r6:40946400 r5:85399c01 r4:00000000 [<8058f6b8>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfb4dfa8 to 0xdfb4dff0) dfa0: 00000000 00000000 00000003 40946400 200000c0 00000000 dfc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76f430dc dfe0: 76f42e88 76f42e78 00018ba0 001300f0 r10:00000036 r9:84713c00 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