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: 3776 Comm: syz.0.14 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 : [<8143e4a8>] lr : [<8143e494>] psr: 60000013 sp : e01f9cb8 ip : e01f9cb8 fp : e01f9cd4 r10: 00000000 r9 : 00000084 r8 : e01f9da4 r7 : 00004f27 r6 : 0000009b r5 : 845c2c00 r4 : 00004f2a r3 : 0000009b r2 : fee04f2a r1 : 00000001 r0 : 845c2c00 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 8604c580 DAC: fffffffd Register r0 information: slab kmalloc-192 start 845c2c00 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 845c2c00 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 0xe01f8000 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 0xe01f8000 allocated at kernel_clone+0xac/0x428 kernel/fork.c:2654 Register r12 information: 2-page vmalloc region starting at 0xe01f8000 allocated at kernel_clone+0xac/0x428 kernel/fork.c:2654 Process syz.0.14 (pid: 3776, stack limit = 0xe01f8000) Stack: (0xe01f9cb8 to 0xe01fa000) 9ca0: 8143e448 00004f27 9cc0: 845c2c00 00004f27 e01f9cf4 e01f9cd8 8143e184 8143e454 00004f27 80522770 9ce0: 84d93800 84d93800 e01f9d14 e01f9cf8 8143e53c 8143e138 845c2c00 00000000 9d00: 84d93800 00004f27 e01f9d54 e01f9d18 8143e6ec 8143e4c0 829d6e04 845c2c00 9d20: 00000000 00000000 845c2c00 829d6e04 845c2c00 00000000 e01f9d90 845c2c00 9d40: 00000000 82b2efdc e01f9d8c e01f9d58 8142d030 8143e684 40946400 00000000 9d60: e01f9d7c 200000c0 845c2c00 b5403587 40946400 00000003 00000003 839a4800 9d80: e01f9e4c e01f9d90 8142883c 8142cf30 35353238 00000000 00000000 00000000 9da0: 00000000 00004f27 00000005 00000002 00000401 00000001 00000cc7 00000fff 9dc0: 5c952399 80000005 000003ff 00000802 00001600 00000001 00000000 00000009 9de0: 0000e1cb 00000006 00000004 00000003 00000395 80000089 fffffffd 00000000 9e00: fffffff5 ffffeadc 00000003 0000003c 00000008 00000004 08000000 dffffffa 9e20: 00000000 1d0c1267 839a4800 8388f780 845c2c00 200000c0 40946400 00000003 9e40: e01f9f14 e01f9e50 81429b60 81428774 00000000 1d0c1267 00000000 00000000 9e60: 824b857c e01f9ea4 0000005f 8451c250 00000064 845c2c30 e01f9ee4 e01f9e88 9e80: 807cda48 807c3e20 00000064 00000001 00000000 e01f9ea4 830ce490 83439000 9ea0: 00006400 0000000b e01f9e98 00000000 00000000 1d0c1267 00000000 8388f780 9ec0: 40946400 200000c0 200000c0 8388f780 00000003 839a4800 e01f9ef4 e01f9ee8 9ee0: 807cdb78 1d0c1267 e01f9f14 00000000 8388f781 40946400 200000c0 8388f780 9f00: 00000003 839a4800 e01f9fa4 e01f9f18 8058f958 81429818 ecac8b10 839a4800 9f20: e01f9f3c e01f9f30 81ae1a14 81ae18e0 e01f9f54 e01f9f40 8025a868 8028c368 9f40: e01f9fb0 40000000 e01f9f84 e01f9f58 80220bf8 8025a824 00000000 8281d2bc 9f60: e01f9fb0 0013e480 ecac8b10 80220b4c 00000000 1d0c1267 e01f9fac 00000000 9f80: 00000000 00346310 00000036 8020029c 839a4800 00000036 00000000 e01f9fa8 9fa0: 80200060 8058f720 00000000 00000000 00000003 40946400 200000c0 00000000 9fc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76f6e0dc 9fe0: 76f6de88 76f6de78 00018ba0 001302e0 60000010 00000003 00000000 00000000 Call trace: [<8143e448>] (subdev_8255_io) from [<8143e184>] (subdev_8255_do_config+0x58/0x60 drivers/comedi/drivers/comedi_8255.c:115) r7:00004f27 r6:845c2c00 r5:00004f27 r4:8143e448 [<8143e12c>] (subdev_8255_do_config) from [<8143e53c>] (__subdev_8255_init drivers/comedi/drivers/comedi_8255.c:172 [inline]) [<8143e12c>] (subdev_8255_do_config) from [<8143e53c>] (subdev_8255_io_init+0x88/0x98 drivers/comedi/drivers/comedi_8255.c:192) r4:84d93800 [<8143e4b4>] (subdev_8255_io_init) from [<8143e6ec>] (dev_8255_attach drivers/comedi/drivers/8255.c:82 [inline]) [<8143e4b4>] (subdev_8255_io_init) from [<8143e6ec>] (dev_8255_attach+0x74/0x120 drivers/comedi/drivers/8255.c:46) r7:00004f27 r6:84d93800 r5:00000000 r4:845c2c00 [<8143e678>] (dev_8255_attach) from [<8142d030>] (comedi_device_attach+0x10c/0x248 drivers/comedi/drivers.c:1069) r10:82b2efdc r9:00000000 r8:845c2c00 r7:e01f9d90 r6:00000000 r5:845c2c00 r4:829d6e04 [<8142cf24>] (comedi_device_attach) from [<8142883c>] (do_devconfig_ioctl+0xd4/0x21c drivers/comedi/comedi_fops.c:928) r10:839a4800 r9:00000003 r8:00000003 r7:40946400 r6:b5403587 r5:845c2c00 r4:200000c0 [<81428768>] (do_devconfig_ioctl) from [<81429b60>] (comedi_unlocked_ioctl+0x354/0x1dbc drivers/comedi/comedi_fops.c:2300) r8:00000003 r7:40946400 r6:200000c0 r5:845c2c00 r4:8388f780 [<8142980c>] (comedi_unlocked_ioctl) from [<8058f958>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<8142980c>] (comedi_unlocked_ioctl) from [<8058f958>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<8142980c>] (comedi_unlocked_ioctl) from [<8058f958>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<8142980c>] (comedi_unlocked_ioctl) from [<8058f958>] (sys_ioctl+0x244/0xb5c fs/ioctl.c:583) r10:839a4800 r9:00000003 r8:8388f780 r7:200000c0 r6:40946400 r5:8388f781 r4:00000000 [<8058f714>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xe01f9fa8 to 0xe01f9ff0) 9fa0: 00000000 00000000 00000003 40946400 200000c0 00000000 9fc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76f6e0dc 9fe0: 76f6de88 76f6de78 00018ba0 001302e0 r10:00000036 r9:839a4800 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