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: 7684 Comm: syz.0.682 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 : [<81416474>] lr : [<81416460>] psr: 60000013 sp : e01d1cb0 ip : e01d1cb0 fp : e01d1ccc r10: 00000001 r9 : 00000084 r8 : e01d1d9c r7 : 00004f27 r6 : 0000009b r5 : 844ba540 r4 : 00004f2a r3 : 0000009b r2 : fee04f2a r1 : 00000001 r0 : 844ba540 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 8648e240 DAC: fffffffd Register r0 information: slab kmalloc-192 start 844ba540 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 844ba540 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 0xe01d0000 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 0xe01d0000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2651 Register r12 information: 2-page vmalloc region starting at 0xe01d0000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2651 Process syz.0.682 (pid: 7684, stack limit = 0xe01d0000) Stack: (0xe01d1cb0 to 0xe01d2000) 1ca0: 81416414 844ba540 00004f27 00004f27 1cc0: e01d1cec e01d1cd0 8141614c 81416420 00004f27 80515264 85d50000 85d50000 1ce0: e01d1d0c e01d1cf0 8141650c 81416100 844ba540 00000000 85d50000 00004f27 1d00: e01d1d4c e01d1d10 814166b8 8141648c 8280ca60 84b0eb00 828215b0 00000000 1d20: 00000000 829d46a0 844ba540 844ba584 e01d1d88 844ba540 00000000 82b28ad8 1d40: e01d1d84 e01d1d50 814051ec 81416650 b5403587 00000000 8383e000 200000c0 1d60: 844ba540 b5403587 844ba570 8383e000 40946400 00000003 e01d1e44 e01d1d88 1d80: 81400b44 814050f0 35353238 00000000 00000000 00000000 00000000 00004f27 1da0: 00000005 00000002 00000401 00000001 00000cc7 00000fff 5c95239c 00000005 1dc0: 000003ff 00000802 00001600 00000001 00000001 00000009 0000e1cb 00000006 1de0: 00000004 00000003 00000395 80000089 fffffffe 0000000b fffffff5 ffffeadb 1e00: 00000003 0000003c 00000000 00000004 08000000 dffffffa 00000000 28ed7362 1e20: 00000000 85836cc0 844ba540 200000c0 844ba570 8383e000 e01d1f14 e01d1e48 1e40: 81401b38 81400a50 00000000 00000000 00000000 00000000 00000000 28ed7362 1e60: 00000000 00000000 824a45ec 0000005f 841c0c28 00000064 846376cc 8383e000 1e80: e01d1ee4 e01d1e90 807b8338 807ae85c 00000064 00000001 00000000 e01d1eac 1ea0: 8603ec10 834e8220 00006400 0000000b e01d1ea0 00000000 00000000 28ed7362 1ec0: 85836cc0 40946400 200000c0 200000c0 85836cc0 00000003 e01d1ef4 e01d1ee8 1ee0: 807b8458 28ed7362 e01d1f14 40946400 00000000 85836cc1 200000c0 85836cc0 1f00: 00000003 8383e000 e01d1fa4 e01d1f18 80585920 81401588 ecac8b10 8383e000 1f20: e01d1f3c e01d1f30 81ab036c 81ab023c e01d1f54 e01d1f40 8025bcbc 8028e0c4 1f40: e01d1fb0 40000000 e01d1f84 e01d1f58 80221a38 8025bc78 00000000 8281cf7c 1f60: e01d1fb0 0014c8c0 ecac8b10 8022198c 00000000 28ed7362 e01d1fac 00000000 1f80: 00000000 00326310 00000036 8020029c 8383e000 00000036 00000000 e01d1fa8 1fa0: 80200060 805857fc 00000000 00000000 00000003 40946400 200000c0 00000000 1fc0: 00000000 00000000 00326310 00000036 00310000 00000000 00006364 76f8e0bc 1fe0: 76f8dec0 76f8deb0 000192bc 00132360 60000010 00000003 00000000 00000000 Call trace: [<81416414>] (subdev_8255_io) from [<8141614c>] (subdev_8255_do_config+0x58/0x60 drivers/comedi/drivers/comedi_8255.c:115) r7:00004f27 r6:00004f27 r5:844ba540 r4:81416414 [<814160f4>] (subdev_8255_do_config) from [<8141650c>] (__subdev_8255_init drivers/comedi/drivers/comedi_8255.c:172 [inline]) [<814160f4>] (subdev_8255_do_config) from [<8141650c>] (subdev_8255_io_init+0x8c/0x9c drivers/comedi/drivers/comedi_8255.c:192) r4:85d50000 [<81416480>] (subdev_8255_io_init) from [<814166b8>] (dev_8255_attach drivers/comedi/drivers/8255.c:82 [inline]) [<81416480>] (subdev_8255_io_init) from [<814166b8>] (dev_8255_attach+0x74/0x120 drivers/comedi/drivers/8255.c:46) r7:00004f27 r6:85d50000 r5:00000000 r4:844ba540 [<81416644>] (dev_8255_attach) from [<814051ec>] (comedi_device_attach+0x108/0x250 drivers/comedi/drivers.c:1069) r10:82b28ad8 r9:00000000 r8:844ba540 r7:e01d1d88 r6:844ba584 r5:844ba540 r4:829d46a0 [<814050e4>] (comedi_device_attach) from [<81400b44>] (do_devconfig_ioctl+0x100/0x220 drivers/comedi/comedi_fops.c:928) r10:00000003 r9:40946400 r8:8383e000 r7:844ba570 r6:b5403587 r5:844ba540 r4:200000c0 [<81400a44>] (do_devconfig_ioctl) from [<81401b38>] (comedi_unlocked_ioctl+0x5bc/0x1c2c drivers/comedi/comedi_fops.c:2240) r8:8383e000 r7:844ba570 r6:200000c0 r5:844ba540 r4:85836cc0 [<8140157c>] (comedi_unlocked_ioctl) from [<80585920>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<8140157c>] (comedi_unlocked_ioctl) from [<80585920>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<8140157c>] (comedi_unlocked_ioctl) from [<80585920>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<8140157c>] (comedi_unlocked_ioctl) from [<80585920>] (sys_ioctl+0x130/0xba0 fs/ioctl.c:583) r10:8383e000 r9:00000003 r8:85836cc0 r7:200000c0 r6:85836cc1 r5:00000000 r4:40946400 [<805857f0>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xe01d1fa8 to 0xe01d1ff0) 1fa0: 00000000 00000000 00000003 40946400 200000c0 00000000 1fc0: 00000000 00000000 00326310 00000036 00310000 00000000 00006364 76f8e0bc 1fe0: 76f8dec0 76f8deb0 000192bc 00132360 r10:00000036 r9:8383e000 r8:8020029c r7:00000036 r6:00326310 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