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: 1 UID: 0 PID: 4379 Comm: syz.1.100 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 : [<8143e0e0>] lr : [<8143e0cc>] psr: 60000013 sp : dfbf9cb8 ip : dfbf9cb8 fp : dfbf9cd4 r10: 00000000 r9 : 00000084 r8 : dfbf9da4 r7 : 00004f27 r6 : 0000009b r5 : 83019d80 r4 : 00004f2a r3 : 0000009b r2 : fee04f2a r1 : 00000001 r0 : 83019d80 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 85e23a00 DAC: 00000000 Register r0 information: slab kmalloc-192 start 83019d80 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 83019d80 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 0xdfbf8000 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 0xdfbf8000 allocated at kernel_clone+0xac/0x428 kernel/fork.c:2654 Register r12 information: 2-page vmalloc region starting at 0xdfbf8000 allocated at kernel_clone+0xac/0x428 kernel/fork.c:2654 Process syz.1.100 (pid: 4379, stack limit = 0xdfbf8000) Stack: (0xdfbf9cb8 to 0xdfbfa000) 9ca0: 8143e080 00004f27 9cc0: 83019d80 00004f27 dfbf9cf4 dfbf9cd8 8143ddbc 8143e08c 00004f27 80522490 9ce0: 8513b000 8513b000 dfbf9d14 dfbf9cf8 8143e174 8143dd70 83019d80 00000000 9d00: 8513b000 00004f27 dfbf9d54 dfbf9d18 8143e324 8143e0f8 82afeb7c 841bbd80 9d20: 828217c0 00000000 00000000 829d6e04 83019d80 00000000 dfbf9d90 83019d80 9d40: 00000000 82b2efdc dfbf9d8c dfbf9d58 8142cc5c 8143e2bc 40946400 00000000 9d60: dfbf9d7c 200000c0 83019d80 b5403587 40946400 00000003 00000005 8462d400 9d80: dfbf9e4c dfbf9d90 81428470 8142cb5c 35353238 00000000 00000000 00000000 9da0: 00000000 00004f27 00000005 00000002 00000401 00000001 00000cc7 00000fff 9dc0: 5c952399 00000005 000003ff 00000802 00001600 00000001 00000001 00000009 9de0: 0000e1cb 00000006 00000004 00000003 00000395 80000089 fffffffd 00000000 9e00: fffffff5 ffffeadb 00000003 0000003c 00000008 00000004 08000000 dffffffa 9e20: 00000000 d02f4e2e 00000000 84dc5540 83019d80 200000c0 40946400 00000003 9e40: dfbf9f14 dfbf9e50 81429794 814283a8 00000000 d02f4e2e 00000000 00000000 9e60: 824b857c dfbf9ea4 0000005f 84292a30 00000064 83019db0 dfbf9ee4 dfbf9e88 9e80: 807cd6ec 807c3ac4 00000064 00000001 00000000 dfbf9ea4 8385cd90 83426990 9ea0: 00006400 0000000b dfbf9e98 00000000 00000000 d02f4e2e 00000000 84dc5540 9ec0: 40946400 200000c0 200000c0 84dc5540 00000005 8462d400 dfbf9ef4 dfbf9ee8 9ee0: 807cd81c d02f4e2e dfbf9f14 00000000 84dc5541 40946400 200000c0 84dc5540 9f00: 00000005 8462d400 dfbf9fa4 dfbf9f18 8058f600 8142944c ecac8b10 8462d400 9f20: dfbf9f3c dfbf9f30 81ae15b4 81ae1480 dfbf9f54 dfbf9f40 8025a85c 8028c030 9f40: dfbf9fb0 40000000 dfbf9f84 dfbf9f58 80220bf8 8025a818 00000000 8281d2bc 9f60: dfbf9fb0 0013e290 ecac8b10 80220b4c 00000000 d02f4e2e dfbf9fac 00000000 9f80: 00000000 00346310 00000036 8020029c 8462d400 00000036 00000000 dfbf9fa8 9fa0: 80200060 8058f3c8 00000000 00000000 00000005 40946400 200000c0 00000000 9fc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76f7a0dc 9fe0: 76f79e88 76f79e78 00018ba0 001300f0 60000010 00000005 00000000 00000000 Call trace: [<8143e080>] (subdev_8255_io) from [<8143ddbc>] (subdev_8255_do_config+0x58/0x60 drivers/comedi/drivers/comedi_8255.c:115) r7:00004f27 r6:83019d80 r5:00004f27 r4:8143e080 [<8143dd64>] (subdev_8255_do_config) from [<8143e174>] (__subdev_8255_init drivers/comedi/drivers/comedi_8255.c:172 [inline]) [<8143dd64>] (subdev_8255_do_config) from [<8143e174>] (subdev_8255_io_init+0x88/0x98 drivers/comedi/drivers/comedi_8255.c:192) r4:8513b000 [<8143e0ec>] (subdev_8255_io_init) from [<8143e324>] (dev_8255_attach drivers/comedi/drivers/8255.c:82 [inline]) [<8143e0ec>] (subdev_8255_io_init) from [<8143e324>] (dev_8255_attach+0x74/0x120 drivers/comedi/drivers/8255.c:46) r7:00004f27 r6:8513b000 r5:00000000 r4:83019d80 [<8143e2b0>] (dev_8255_attach) from [<8142cc5c>] (comedi_device_attach+0x10c/0x248 drivers/comedi/drivers.c:1069) r10:82b2efdc r9:00000000 r8:83019d80 r7:dfbf9d90 r6:00000000 r5:83019d80 r4:829d6e04 [<8142cb50>] (comedi_device_attach) from [<81428470>] (do_devconfig_ioctl+0xd4/0x21c drivers/comedi/comedi_fops.c:928) r10:8462d400 r9:00000005 r8:00000003 r7:40946400 r6:b5403587 r5:83019d80 r4:200000c0 [<8142839c>] (do_devconfig_ioctl) from [<81429794>] (comedi_unlocked_ioctl+0x354/0x1dbc drivers/comedi/comedi_fops.c:2300) r8:00000003 r7:40946400 r6:200000c0 r5:83019d80 r4:84dc5540 [<81429440>] (comedi_unlocked_ioctl) from [<8058f600>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<81429440>] (comedi_unlocked_ioctl) from [<8058f600>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<81429440>] (comedi_unlocked_ioctl) from [<8058f600>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<81429440>] (comedi_unlocked_ioctl) from [<8058f600>] (sys_ioctl+0x244/0xb5c fs/ioctl.c:583) r10:8462d400 r9:00000005 r8:84dc5540 r7:200000c0 r6:40946400 r5:84dc5541 r4:00000000 [<8058f3bc>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfbf9fa8 to 0xdfbf9ff0) 9fa0: 00000000 00000000 00000005 40946400 200000c0 00000000 9fc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76f7a0dc 9fe0: 76f79e88 76f79e78 00018ba0 001300f0 r10:00000036 r9:8462d400 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