8<--- cut here --- Unable to handle kernel paging request at virtual address fee00403 when write [fee00403] *pgd=80000080007003, *pmd=00000000 Internal error: Oops: a06 [#1] SMP ARM Modules linked in: CPU: 1 UID: 0 PID: 11504 Comm: syz.8.1571 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 : [<81441000>] lr : [<81440fec>] psr: 60000013 sp : dfb15cb8 ip : dfb15cb8 fp : dfb15cd4 r10: 00000000 r9 : 00000084 r8 : dfb15da4 r7 : 00000400 r6 : 0000009b r5 : 842e09c0 r4 : 00000403 r3 : 0000009b r2 : fee00403 r1 : 00000001 r0 : 842e09c0 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 87007d80 DAC: 00000000 Register r0 information: slab kmalloc-192 start 842e09c0 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 842e09c0 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 0xdfb14000 allocated at kernel_clone+0xac/0x42c kernel/fork.c:2653 Register r9 information: non-paged memory Register r10 information: NULL pointer Register r11 information: 2-page vmalloc region starting at 0xdfb14000 allocated at kernel_clone+0xac/0x42c kernel/fork.c:2653 Register r12 information: 2-page vmalloc region starting at 0xdfb14000 allocated at kernel_clone+0xac/0x42c kernel/fork.c:2653 Process syz.8.1571 (pid: 11504, stack limit = 0xdfb14000) Stack: (0xdfb15cb8 to 0xdfb16000) 5ca0: 81440fa0 00000400 5cc0: 842e09c0 00000400 dfb15cf4 dfb15cd8 81440cdc 81440fac 00000400 805236b8 5ce0: 86cfce40 86cfce40 dfb15d14 dfb15cf8 81441094 81440c90 842e09c0 00000000 5d00: 86cfce40 00000400 dfb15d54 dfb15d18 81441244 81441018 82b0d0ac 84df5a00 5d20: 82821800 00000000 00000000 829d6f04 842e09c0 00000000 dfb15d90 842e09c0 5d40: 00000000 82b2f06c dfb15d8c dfb15d58 8142fb8c 814411dc 40946400 00000000 5d60: dfb15d7c 20000440 842e09c0 b5403587 40946400 00000001 00000008 84814980 5d80: dfb15e4c dfb15d90 8142b398 8142fa8c 35353238 00000000 00000000 00000000 5da0: 00000000 00000400 00000000 00000a1a 00000004 00000006 0800afa3 00000000 5dc0: 00000004 00000002 00000007 00000007 00000009 00000001 00000009 00000006 5de0: 00000002 00006f48 00000004 00000002 0000000a 00000006 0000caa2 20001003 5e00: 20001e5b 02000003 00000e69 00000002 00006871 00004086 00000000 000006f5 5e20: 00000000 8e7cafab 00000000 838a6480 842e09c0 20000440 40946400 00000001 5e40: dfb15f14 dfb15e50 8142c6bc 8142b2d0 00000000 8e7cafab 00000000 00000000 5e60: 824b957c dfb15ea4 0000005f 843f9be8 00000064 842e09f0 dfb15ee4 dfb15e88 5e80: 807cf448 807c5820 00000064 00000001 00000000 dfb15ea4 863f7310 8343baa0 5ea0: 00006400 0000000b dfb15e98 00000000 00000000 8e7cafab 00000000 838a6480 5ec0: 40946400 20000440 20000440 838a6480 00000008 84814980 dfb15ef4 dfb15ee8 5ee0: 807cf578 8e7cafab dfb15f14 00000000 838a6481 40946400 20000440 838a6480 5f00: 00000008 84814980 dfb15fa4 dfb15f18 805908e4 8142c374 ecac8b10 84814980 5f20: dfb15f3c dfb15f30 81ae5234 81ae5100 dfb15f54 dfb15f40 8025a87c 8028c380 5f40: dfb15fb0 40000000 dfb15f84 dfb15f58 80220bf8 8025a838 00000000 8281d2fc 5f60: dfb15fb0 0013e480 ecac8b10 80220b4c 00000000 8e7cafab dfb15fac 00000000 5f80: 00000000 00346450 00000036 8020029c 84814980 00000036 00000000 dfb15fa8 5fa0: 80200060 805906ac 00000000 00000000 00000008 40946400 20000440 00000000 5fc0: 00000000 00000000 00346450 00000036 00346418 00000000 00000001 76f0c0dc 5fe0: 76f0be88 76f0be78 00018ba0 001302e0 60000010 00000008 00000000 00000000 Call trace: [<81440fa0>] (subdev_8255_io) from [<81440cdc>] (subdev_8255_do_config+0x58/0x60 drivers/comedi/drivers/comedi_8255.c:115) r7:00000400 r6:842e09c0 r5:00000400 r4:81440fa0 [<81440c84>] (subdev_8255_do_config) from [<81441094>] (__subdev_8255_init drivers/comedi/drivers/comedi_8255.c:172 [inline]) [<81440c84>] (subdev_8255_do_config) from [<81441094>] (subdev_8255_io_init+0x88/0x98 drivers/comedi/drivers/comedi_8255.c:192) r4:86cfce40 [<8144100c>] (subdev_8255_io_init) from [<81441244>] (dev_8255_attach drivers/comedi/drivers/8255.c:82 [inline]) [<8144100c>] (subdev_8255_io_init) from [<81441244>] (dev_8255_attach+0x74/0x120 drivers/comedi/drivers/8255.c:46) r7:00000400 r6:86cfce40 r5:00000000 r4:842e09c0 [<814411d0>] (dev_8255_attach) from [<8142fb8c>] (comedi_device_attach+0x10c/0x248 drivers/comedi/drivers.c:1069) r10:82b2f06c r9:00000000 r8:842e09c0 r7:dfb15d90 r6:00000000 r5:842e09c0 r4:829d6f04 [<8142fa80>] (comedi_device_attach) from [<8142b398>] (do_devconfig_ioctl+0xd4/0x21c drivers/comedi/comedi_fops.c:928) r10:84814980 r9:00000008 r8:00000001 r7:40946400 r6:b5403587 r5:842e09c0 r4:20000440 [<8142b2c4>] (do_devconfig_ioctl) from [<8142c6bc>] (comedi_unlocked_ioctl+0x354/0x1dbc drivers/comedi/comedi_fops.c:2300) r8:00000001 r7:40946400 r6:20000440 r5:842e09c0 r4:838a6480 [<8142c368>] (comedi_unlocked_ioctl) from [<805908e4>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<8142c368>] (comedi_unlocked_ioctl) from [<805908e4>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<8142c368>] (comedi_unlocked_ioctl) from [<805908e4>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<8142c368>] (comedi_unlocked_ioctl) from [<805908e4>] (sys_ioctl+0x244/0xb5c fs/ioctl.c:583) r10:84814980 r9:00000008 r8:838a6480 r7:20000440 r6:40946400 r5:838a6481 r4:00000000 [<805906a0>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfb15fa8 to 0xdfb15ff0) 5fa0: 00000000 00000000 00000008 40946400 20000440 00000000 5fc0: 00000000 00000000 00346450 00000036 00346418 00000000 00000001 76f0c0dc 5fe0: 76f0be88 76f0be78 00018ba0 001302e0 r10:00000036 r9:84814980 r8:8020029c r7:00000036 r6:00346450 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