8<--- cut here --- Unable to handle kernel paging request at virtual address fee04f2a when write [fee04f2a] *pgd=80000080007003, *pmd=00000000 Internal error: Oops: a06 [#1] SMP ARM Modules linked in: CPU: 0 UID: 0 PID: 5512 Comm: syz.1.397 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 : [<8143e7d0>] lr : [<8143e7bc>] psr: 60000013 sp : dfce9cb8 ip : dfce9cb8 fp : dfce9cd4 r10: 00000000 r9 : 00000084 r8 : dfce9da4 r7 : 00004f27 r6 : 0000009b r5 : 83019000 r4 : 00004f2a r3 : 0000009b r2 : fee04f2a r1 : 00000001 r0 : 83019000 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 8644b640 DAC: fffffffd Register r0 information: slab kmalloc-192 start 83019000 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 83019000 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 0xdfce8000 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 0xdfce8000 allocated at kernel_clone+0xac/0x428 kernel/fork.c:2654 Register r12 information: 2-page vmalloc region starting at 0xdfce8000 allocated at kernel_clone+0xac/0x428 kernel/fork.c:2654 Process syz.1.397 (pid: 5512, stack limit = 0xdfce8000) Stack: (0xdfce9cb8 to 0xdfcea000) 9ca0: 8143e770 00004f27 9cc0: 83019000 00004f27 dfce9cf4 dfce9cd8 8143e4ac 8143e77c 00004f27 805228cc 9ce0: 846cb000 846cb000 dfce9d14 dfce9cf8 8143e864 8143e460 83019000 00000000 9d00: 846cb000 00004f27 dfce9d54 dfce9d18 8143ea14 8143e7e8 82afe43c 84790880 9d20: 828217c0 00000000 00000000 829d6e04 83019000 00000000 dfce9d90 83019000 9d40: 00000000 82b2efdc dfce9d8c dfce9d58 8142d34c 8143e9ac 40946400 00000000 9d60: dfce9d7c 200000c0 83019000 b5403587 40946400 00000003 00000003 84ff8000 9d80: dfce9e4c dfce9d90 81428b60 8142d24c 35353238 00000000 00000000 00000000 9da0: 00000000 00004f27 00000005 00000022 00000401 00000001 00006dc4 00000fff 9dc0: 5c95239c 00000005 000003ff 00000806 00000401 00000001 00000002 00000009 9de0: 0000e1cb 00000005 00000004 00000003 00000395 8000008b fffffffe 0000000a 9e00: fffffff5 00000001 00000003 00000000 00000000 00000004 08000000 dffffff9 9e20: 00000000 89ca2fb5 00000000 867be300 83019000 200000c0 40946400 00000003 9e40: dfce9f14 dfce9e50 81429e84 81428a98 00000000 89ca2fb5 00000000 00000000 9e60: 824b857c dfce9ea4 0000005f 847b2640 00000064 83019030 dfce9ee4 dfce9e88 9e80: 807cdac4 807c3e9c 00000064 00000001 00000000 dfce9ea4 8337d6d0 8342f330 9ea0: 00006400 0000000b dfce9e98 00000000 00000000 89ca2fb5 00000000 867be300 9ec0: 40946400 200000c0 200000c0 867be300 00000003 84ff8000 dfce9ef4 dfce9ee8 9ee0: 807cdbf4 89ca2fb5 dfce9f14 00000000 867be301 40946400 200000c0 867be300 9f00: 00000003 84ff8000 dfce9fa4 dfce9f18 8058fa6c 81429b3c ecac8b10 84ff8000 9f20: dfce9f3c dfce9f30 81ae1ad4 81ae19a0 dfce9f54 dfce9f40 8025a85c 8028c340 9f40: dfce9fb0 40000000 dfce9f84 dfce9f58 80220bf8 8025a818 00000000 8281d2bc 9f60: dfce9fb0 0013e290 ecac8b10 80220b4c 00000000 89ca2fb5 dfce9fac 00000000 9f80: 00000000 00346310 00000036 8020029c 84ff8000 00000036 00000000 dfce9fa8 9fa0: 80200060 8058f834 00000000 00000000 00000003 40946400 200000c0 00000000 9fc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76f880dc 9fe0: 76f87e88 76f87e78 00018ba0 001300f0 60000010 00000003 00000000 00000000 Call trace: [<8143e770>] (subdev_8255_io) from [<8143e4ac>] (subdev_8255_do_config+0x58/0x60 drivers/comedi/drivers/comedi_8255.c:115) r7:00004f27 r6:83019000 r5:00004f27 r4:8143e770 [<8143e454>] (subdev_8255_do_config) from [<8143e864>] (__subdev_8255_init drivers/comedi/drivers/comedi_8255.c:172 [inline]) [<8143e454>] (subdev_8255_do_config) from [<8143e864>] (subdev_8255_io_init+0x88/0x98 drivers/comedi/drivers/comedi_8255.c:192) r4:846cb000 [<8143e7dc>] (subdev_8255_io_init) from [<8143ea14>] (dev_8255_attach drivers/comedi/drivers/8255.c:82 [inline]) [<8143e7dc>] (subdev_8255_io_init) from [<8143ea14>] (dev_8255_attach+0x74/0x120 drivers/comedi/drivers/8255.c:46) r7:00004f27 r6:846cb000 r5:00000000 r4:83019000 [<8143e9a0>] (dev_8255_attach) from [<8142d34c>] (comedi_device_attach+0x10c/0x248 drivers/comedi/drivers.c:1069) r10:82b2efdc r9:00000000 r8:83019000 r7:dfce9d90 r6:00000000 r5:83019000 r4:829d6e04 [<8142d240>] (comedi_device_attach) from [<81428b60>] (do_devconfig_ioctl+0xd4/0x21c drivers/comedi/comedi_fops.c:928) r10:84ff8000 r9:00000003 r8:00000003 r7:40946400 r6:b5403587 r5:83019000 r4:200000c0 [<81428a8c>] (do_devconfig_ioctl) from [<81429e84>] (comedi_unlocked_ioctl+0x354/0x1dbc drivers/comedi/comedi_fops.c:2300) r8:00000003 r7:40946400 r6:200000c0 r5:83019000 r4:867be300 [<81429b30>] (comedi_unlocked_ioctl) from [<8058fa6c>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<81429b30>] (comedi_unlocked_ioctl) from [<8058fa6c>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<81429b30>] (comedi_unlocked_ioctl) from [<8058fa6c>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<81429b30>] (comedi_unlocked_ioctl) from [<8058fa6c>] (sys_ioctl+0x244/0xb5c fs/ioctl.c:583) r10:84ff8000 r9:00000003 r8:867be300 r7:200000c0 r6:40946400 r5:867be301 r4:00000000 [<8058f828>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfce9fa8 to 0xdfce9ff0) 9fa0: 00000000 00000000 00000003 40946400 200000c0 00000000 9fc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76f880dc 9fe0: 76f87e88 76f87e78 00018ba0 001300f0 r10:00000036 r9:84ff8000 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