8<--- cut here --- Unable to handle kernel paging request at virtual address fee08004 when write [fee08004] *pgd=80000080007003, *pmd=00000000 Internal error: Oops: a06 [#1] SMP ARM Modules linked in: CPU: 1 UID: 0 PID: 3760 Comm: syz.1.15 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 : [<8141571c>] lr : [<81415708>] psr: 60000013 sp : dfa49cb0 ip : dfa49cb0 fp : dfa49ccc r10: 00000001 r9 : 00000084 r8 : dfa49d9c r7 : 00008001 r6 : 0000009b r5 : 844f8e40 r4 : 00008004 r3 : 0000009b r2 : fee08004 r1 : 00000001 r0 : 844f8e40 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 85cf99c0 DAC: 00000000 Register r0 information: slab kmalloc-192 start 844f8e40 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 844f8e40 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 0xdfa48000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2651 Register r9 information: non-paged memory Register r10 information: non-paged memory Register r11 information: 2-page vmalloc region starting at 0xdfa48000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2651 Register r12 information: 2-page vmalloc region starting at 0xdfa48000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2651 Process syz.1.15 (pid: 3760, stack limit = 0xdfa48000) Stack: (0xdfa49cb0 to 0xdfa4a000) 9ca0: 814156bc 844f8e40 00008001 00008001 9cc0: dfa49cec dfa49cd0 814153f4 814156c8 00008001 80514ee4 855e5800 855e5800 9ce0: dfa49d0c dfa49cf0 814157b4 814153a8 844f8e40 00000000 855e5800 00008001 9d00: dfa49d4c dfa49d10 81415960 81415734 8280cc60 8452e880 828217b0 00000000 9d20: 00000000 829d46a0 844f8e40 844f8e84 dfa49d88 844f8e40 00000000 82b28ad8 9d40: dfa49d84 dfa49d50 81404490 814158f8 844f8e70 00000000 dfa49d74 200001c0 9d60: 844f8e40 b5403587 844f8e70 845cd400 40946400 00000003 dfa49e44 dfa49d88 9d80: 813ffde8 81404394 35353238 00000000 00000000 00000000 00000000 00008001 9da0: 00000009 00000001 00000009 00000004 00000ccb 00000008 000000ab 00000000 9dc0: 000000fd fffffffd 00000080 00000005 00000002 00000006 ffffffff 00000002 9de0: 00000040 00000001 40000003 ffffffff 00001000 00001000 00000045 fffffffc 9e00: 00010000 0000003c 00000000 4000000c 00000004 ffffffff 00000000 bb235639 9e20: 00000000 8518da80 844f8e40 200001c0 844f8e70 845cd400 dfa49f14 dfa49e48 9e40: 81400ddc 813ffcf4 00000000 00000000 00000000 00000000 00000000 bb235639 9e60: 00000000 00000000 824a35ec 0000005f 84013be8 00000064 84606684 845cd400 9e80: dfa49ee4 dfa49e90 807b7d30 807ae254 00000064 00000001 00000000 dfa49eac 9ea0: 84d55490 834deaa0 00006400 0000000b dfa49ea0 00000000 00000000 bb235639 9ec0: 8518da80 40946400 200001c0 200001c0 8518da80 00000003 dfa49ef4 dfa49ee8 9ee0: 807b7e50 bb235639 dfa49f14 40946400 00000000 8518da81 200001c0 8518da80 9f00: 00000003 845cd400 dfa49fa4 dfa49f18 805854f4 8140082c ecac8b10 845cd400 9f20: dfa49f3c dfa49f30 81aaf27c 81aaf14c dfa49f54 dfa49f40 8025bcbc 8028e07c 9f40: dfa49fb0 40000000 dfa49f84 dfa49f58 80221a38 8025bc78 00000000 8281d17c 9f60: dfa49fb0 0014c880 ecac8b10 8022198c 00000000 bb235639 dfa49fac 00000000 9f80: 00000000 00316310 00000036 8020029c 845cd400 00000036 00000000 dfa49fa8 9fa0: 80200060 805853d0 00000000 00000000 00000003 40946400 200001c0 00000000 9fc0: 00000000 00000000 00316310 00000036 00300000 00000000 00006364 76f190bc 9fe0: 76f18ec0 76f18eb0 0001929c 00132320 60000010 00000003 00000000 00000000 Call trace: [<814156bc>] (subdev_8255_io) from [<814153f4>] (subdev_8255_do_config+0x58/0x60 drivers/comedi/drivers/comedi_8255.c:115) r7:00008001 r6:00008001 r5:844f8e40 r4:814156bc [<8141539c>] (subdev_8255_do_config) from [<814157b4>] (__subdev_8255_init drivers/comedi/drivers/comedi_8255.c:172 [inline]) [<8141539c>] (subdev_8255_do_config) from [<814157b4>] (subdev_8255_io_init+0x8c/0x9c drivers/comedi/drivers/comedi_8255.c:192) r4:855e5800 [<81415728>] (subdev_8255_io_init) from [<81415960>] (dev_8255_attach drivers/comedi/drivers/8255.c:82 [inline]) [<81415728>] (subdev_8255_io_init) from [<81415960>] (dev_8255_attach+0x74/0x120 drivers/comedi/drivers/8255.c:46) r7:00008001 r6:855e5800 r5:00000000 r4:844f8e40 [<814158ec>] (dev_8255_attach) from [<81404490>] (comedi_device_attach+0x108/0x250 drivers/comedi/drivers.c:1069) r10:82b28ad8 r9:00000000 r8:844f8e40 r7:dfa49d88 r6:844f8e84 r5:844f8e40 r4:829d46a0 [<81404388>] (comedi_device_attach) from [<813ffde8>] (do_devconfig_ioctl+0x100/0x220 drivers/comedi/comedi_fops.c:928) r10:00000003 r9:40946400 r8:845cd400 r7:844f8e70 r6:b5403587 r5:844f8e40 r4:200001c0 [<813ffce8>] (do_devconfig_ioctl) from [<81400ddc>] (comedi_unlocked_ioctl+0x5bc/0x1c2c drivers/comedi/comedi_fops.c:2240) r8:845cd400 r7:844f8e70 r6:200001c0 r5:844f8e40 r4:8518da80 [<81400820>] (comedi_unlocked_ioctl) from [<805854f4>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<81400820>] (comedi_unlocked_ioctl) from [<805854f4>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<81400820>] (comedi_unlocked_ioctl) from [<805854f4>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<81400820>] (comedi_unlocked_ioctl) from [<805854f4>] (sys_ioctl+0x130/0xba0 fs/ioctl.c:583) r10:845cd400 r9:00000003 r8:8518da80 r7:200001c0 r6:8518da81 r5:00000000 r4:40946400 [<805853c4>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfa49fa8 to 0xdfa49ff0) 9fa0: 00000000 00000000 00000003 40946400 200001c0 00000000 9fc0: 00000000 00000000 00316310 00000036 00300000 00000000 00006364 76f190bc 9fe0: 76f18ec0 76f18eb0 0001929c 00132320 r10:00000036 r9:845cd400 r8:8020029c r7:00000036 r6:00316310 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