8<--- cut here --- Unable to handle kernel paging request at virtual address fee04f2d when write [fee04f2d] *pgd=80000080007003, *pmd=00000000 Internal error: Oops: a06 [#1] SMP ARM Modules linked in: CPU: 0 UID: 0 PID: 4756 Comm: syz.2.228 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 : [<8145a344>] lr : [<8145a330>] psr: 60000013 sp : dfdb5cb8 ip : dfdb5cb8 fp : dfdb5cd4 r10: 00000000 r9 : 00000084 r8 : dfdb5da4 r7 : 00004f2a r6 : 0000009b r5 : 846c0480 r4 : 00004f2d r3 : 0000009b r2 : fee04f2d r1 : 00000001 r0 : 846c0480 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 864f7440 DAC: fffffffd Register r0 information: slab kmalloc-192 start 846c0480 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:1048 Register r3 information: non-paged memory Register r4 information: non-paged memory Register r5 information: slab kmalloc-192 start 846c0480 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 0xdfdb4000 allocated at kernel_clone+0xbc/0x438 kernel/fork.c:2723 Register r9 information: non-paged memory Register r10 information: NULL pointer Register r11 information: 2-page vmalloc region starting at 0xdfdb4000 allocated at kernel_clone+0xbc/0x438 kernel/fork.c:2723 Register r12 information: 2-page vmalloc region starting at 0xdfdb4000 allocated at kernel_clone+0xbc/0x438 kernel/fork.c:2723 Process syz.2.228 (pid: 4756, stack limit = 0xdfdb4000) Stack: (0xdfdb5cb8 to 0xdfdb6000) 5ca0: 8145a2e4 00004f2a 5cc0: 846c0480 00004f2a dfdb5cf4 dfdb5cd8 8145a020 8145a2f0 00004f2a 8052d15c 5ce0: 855b1c00 855b1c00 dfdb5d14 dfdb5cf8 8145a3d8 81459fd4 846c0480 00000000 5d00: 855b1c00 00004f2a dfdb5d54 dfdb5d18 8145a588 8145a35c 828d69f8 838c5e00 5d20: 82a20600 00000000 00000000 82bd2e5c 846c0480 00000000 dfdb5d90 846c0480 5d40: 00000000 82d2bd4c dfdb5d8c dfdb5d58 81448ecc 8145a520 40946400 00000000 5d60: dfdb5d7c 200000c0 846c0480 b5403587 40946400 00000003 00000008 840a8c40 5d80: dfdb5e4c dfdb5d90 814446e4 81448dd0 35353238 00000000 00000000 00000000 5da0: 00000000 00004f2a 80002002 00010003 00000008 00001000 00000cc7 00000000 5dc0: 0000569b 00000008 00000406 00000005 fffffffd 00000045 0800004f 00000206 5de0: 000000fe 00000000 0001a449 00000009 40000003 0000008b 0000cae4 00000000 5e00: 20001e58 00000008 00000c69 00000040 00000006 00004088 00000000 00000009 5e20: 00000000 e23043f5 00000000 86233c00 846c0480 200000c0 40946400 00000003 5e40: dfdb5f14 dfdb5e50 81445a08 8144461c 00000000 e23043f5 00000000 00000000 5e60: 8252e804 dfdb5ea4 0000005f 8452ab68 00000064 846c04b0 dfdb5ee4 dfdb5e88 5e80: 807ded4c 807d507c 00000064 00000001 00000000 dfdb5ea4 83364550 835b8ee0 5ea0: 00006400 0000000b dfdb5e98 00000000 00000000 e23043f5 00000000 86233c00 5ec0: 40946400 200000c0 200000c0 86233c00 00000008 840a8c40 dfdb5ef4 dfdb5ee8 5ee0: 807dee80 e23043f5 dfdb5f14 00000000 86233c01 40946400 200000c0 86233c00 5f00: 00000008 840a8c40 dfdb5fa4 dfdb5f18 8059c26c 814456c0 ecac8b10 840a8c40 5f20: dfdb5f3c dfdb5f30 81b05714 81b055e0 dfdb5f54 dfdb5f40 8025a4dc 8028c2bc 5f40: dfdb5fb0 40000000 dfdb5f84 dfdb5f58 80220be0 8025a498 00000000 82a1c33c 5f60: dfdb5fb0 0013e940 ecac8b10 80220b34 00000000 e23043f5 dfdb5fac 00000000 5f80: 00000000 003463b0 00000036 8020029c 840a8c40 00000036 00000000 dfdb5fa8 5fa0: 80200060 8059c034 00000000 00000000 00000008 40946400 200000c0 00000000 5fc0: 00000000 00000000 003463b0 00000036 00346378 00000000 00000001 76fb90dc 5fe0: 76fb8e88 76fb8e78 00018e58 001307a0 60000010 00000008 00000000 00000000 Call trace: [<8145a2e4>] (subdev_8255_io) from [<8145a020>] (subdev_8255_do_config+0x58/0x60 drivers/comedi/drivers/comedi_8255.c:115) r7:00004f2a r6:846c0480 r5:00004f2a r4:8145a2e4 [<81459fc8>] (subdev_8255_do_config) from [<8145a3d8>] (__subdev_8255_init drivers/comedi/drivers/comedi_8255.c:172 [inline]) [<81459fc8>] (subdev_8255_do_config) from [<8145a3d8>] (subdev_8255_io_init+0x88/0x98 drivers/comedi/drivers/comedi_8255.c:192) r4:855b1c00 [<8145a350>] (subdev_8255_io_init) from [<8145a588>] (dev_8255_attach drivers/comedi/drivers/8255.c:82 [inline]) [<8145a350>] (subdev_8255_io_init) from [<8145a588>] (dev_8255_attach+0x74/0x120 drivers/comedi/drivers/8255.c:46) r7:00004f2a r6:855b1c00 r5:00000000 r4:846c0480 [<8145a514>] (dev_8255_attach) from [<81448ecc>] (comedi_device_attach+0x108/0x244 drivers/comedi/drivers.c:1077) r10:82d2bd4c r9:00000000 r8:846c0480 r7:dfdb5d90 r6:00000000 r5:846c0480 r4:82bd2e5c [<81448dc4>] (comedi_device_attach) from [<814446e4>] (do_devconfig_ioctl+0xd4/0x21c drivers/comedi/comedi_fops.c:930) r10:840a8c40 r9:00000008 r8:00000003 r7:40946400 r6:b5403587 r5:846c0480 r4:200000c0 [<81444610>] (do_devconfig_ioctl) from [<81445a08>] (comedi_unlocked_ioctl+0x354/0x1db8 drivers/comedi/comedi_fops.c:2302) r8:00000003 r7:40946400 r6:200000c0 r5:846c0480 r4:86233c00 [<814456b4>] (comedi_unlocked_ioctl) from [<8059c26c>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<814456b4>] (comedi_unlocked_ioctl) from [<8059c26c>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<814456b4>] (comedi_unlocked_ioctl) from [<8059c26c>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<814456b4>] (comedi_unlocked_ioctl) from [<8059c26c>] (sys_ioctl+0x244/0xb5c fs/ioctl.c:583) r10:840a8c40 r9:00000008 r8:86233c00 r7:200000c0 r6:40946400 r5:86233c01 r4:00000000 [<8059c028>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfdb5fa8 to 0xdfdb5ff0) 5fa0: 00000000 00000000 00000008 40946400 200000c0 00000000 5fc0: 00000000 00000000 003463b0 00000036 00346378 00000000 00000001 76fb90dc 5fe0: 76fb8e88 76fb8e78 00018e58 001307a0 r10:00000036 r9:840a8c40 r8:8020029c r7:00000036 r6:003463b0 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