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: 21836 Comm: syz.2.4700 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 : [<813db398>] lr : [<813db384>] psr: 60000013 sp : dfaf9cb8 ip : dfaf9cb8 fp : dfaf9cd4 r10: 00000000 r9 : 00000000 r8 : 00000084 r7 : 00004f27 r6 : 0000009b r5 : 840a36c0 r4 : 00004f2a r3 : 0000009b r2 : fee04f2a r1 : 00000001 r0 : 840a36c0 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 85091540 DAC: 00000000 Register r0 information: slab kmalloc-192 start 840a36c0 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 840a36c0 pointer offset 0 size 192 Register r6 information: non-paged memory Register r7 information: non-paged memory Register r8 information: non-paged memory Register r9 information: NULL pointer Register r10 information: NULL pointer Register r11 information: 2-page vmalloc region starting at 0xdfaf8000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2609 Register r12 information: 2-page vmalloc region starting at 0xdfaf8000 allocated at kernel_clone+0xac/0x3ec kernel/fork.c:2609 Process syz.2.4700 (pid: 21836, stack limit = 0xdfaf8000) Stack: (0xdfaf9cb8 to 0xdfafa000) 9ca0: 813db338 840a36c0 9cc0: 00004f27 00004f27 dfaf9cf4 dfaf9cd8 813db070 813db344 00004f27 8050a54c 9ce0: 85221000 85221000 dfaf9d14 dfaf9cf8 813db430 813db024 85221000 840a36c0 9d00: dfaf9da4 00004f27 dfaf9d54 dfaf9d18 813db624 813db3b0 8079d9dc 85b9f900 9d20: 828215f0 00000000 00000000 829d238c 840a36c0 840a3704 dfaf9d90 840a36c0 9d40: 00000000 82b25910 dfaf9d8c dfaf9d58 813ca520 813db574 200000c0 00000000 9d60: dfaf9d7c 200000c0 840a36c0 b5403587 200000c0 85865400 40946400 00000003 9d80: dfaf9e4c dfaf9d90 813c606c 813ca424 35353238 00000000 00000000 00000000 9da0: 00000000 00004f27 00000005 00000002 00000401 00000001 00000cc6 00000fff 9dc0: 5c952399 00000048 000003ff 00000802 00000002 00000003 00000001 00000009 9de0: 0000e1cb 00000006 00080004 00000003 00000392 00000002 fffffffd 00000000 9e00: fffffff5 ffffeadb 00000003 0000003c 00000008 00000004 08000000 00000009 9e20: 00000000 c3bcd47f 00000000 85323e40 840a36c0 200000c0 200000c0 85865400 9e40: dfaf9f14 dfaf9e50 813c7038 813c5f78 00000000 dfaf9e54 dfaf9e54 c3bcd47f 9e60: 00000000 00000000 824625b4 0000005f 840df210 840a36f0 841a436c 85865400 9e80: dfaf9ee4 dfaf9e90 807a779c 8079db94 00000064 00000001 00000000 dfaf9eac 9ea0: 85afca90 83426cc0 00006400 0000000b dfaf9ea0 00000000 dfaf9d30 c3bcd47f 9ec0: 85323e40 40946400 200000c0 200000c0 85323e40 00000003 dfaf9ef4 dfaf9ee8 9ee0: 807a78bc c3bcd47f dfaf9f14 40946400 00000000 85323e41 200000c0 85323e40 9f00: 00000003 85865400 dfaf9fa4 dfaf9f18 805789d0 813c6a68 ecac8b10 85865400 9f20: dfaf9f3c dfaf9f30 81a608b8 81a60788 dfaf9f54 dfaf9f40 8025c484 8028d914 9f40: dfaf9fb0 40000000 dfaf9f84 dfaf9f58 802229ec 8025c440 00000000 8281cfb4 9f60: dfaf9fb0 0014ced0 ecac8b10 80222940 00000000 c3bcd47f dfaf9fac 00000000 9f80: 00000000 00316308 00000036 8020029c 85865400 00000036 00000000 dfaf9fa8 9fa0: 80200060 805788ac 00000000 00000000 00000003 40946400 200000c0 00000000 9fc0: 00000000 00000000 00316308 00000036 00300000 00000000 00006364 76fda0bc 9fe0: 76fd9ec0 76fd9eb0 0001928c 00132970 60000010 00000003 00000000 00000000 Call trace: [<813db338>] (subdev_8255_io) from [<813db070>] (subdev_8255_do_config+0x58/0x60 drivers/comedi/drivers/comedi_8255.c:115) r7:00004f27 r6:00004f27 r5:840a36c0 r4:813db338 [<813db018>] (subdev_8255_do_config) from [<813db430>] (__subdev_8255_init drivers/comedi/drivers/comedi_8255.c:172 [inline]) [<813db018>] (subdev_8255_do_config) from [<813db430>] (subdev_8255_io_init+0x8c/0x9c drivers/comedi/drivers/comedi_8255.c:192) r4:85221000 [<813db3a4>] (subdev_8255_io_init) from [<813db624>] (dev_8255_attach drivers/comedi/drivers/8255.c:83 [inline]) [<813db3a4>] (subdev_8255_io_init) from [<813db624>] (dev_8255_attach+0xbc/0x114 drivers/comedi/drivers/8255.c:46) r7:00004f27 r6:dfaf9da4 r5:840a36c0 r4:85221000 [<813db568>] (dev_8255_attach) from [<813ca520>] (comedi_device_attach+0x108/0x250 drivers/comedi/drivers.c:1007) r10:82b25910 r9:00000000 r8:840a36c0 r7:dfaf9d90 r6:840a3704 r5:840a36c0 r4:829d238c [<813ca418>] (comedi_device_attach) from [<813c606c>] (do_devconfig_ioctl+0x100/0x220 drivers/comedi/comedi_fops.c:872) r10:00000003 r9:40946400 r8:85865400 r7:200000c0 r6:b5403587 r5:840a36c0 r4:200000c0 [<813c5f6c>] (do_devconfig_ioctl) from [<813c7038>] (comedi_unlocked_ioctl+0x5dc/0x1c50 drivers/comedi/comedi_fops.c:2178) r8:85865400 r7:200000c0 r6:200000c0 r5:840a36c0 r4:85323e40 [<813c6a5c>] (comedi_unlocked_ioctl) from [<805789d0>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<813c6a5c>] (comedi_unlocked_ioctl) from [<805789d0>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<813c6a5c>] (comedi_unlocked_ioctl) from [<805789d0>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<813c6a5c>] (comedi_unlocked_ioctl) from [<805789d0>] (sys_ioctl+0x130/0xba0 fs/ioctl.c:583) r10:85865400 r9:00000003 r8:85323e40 r7:200000c0 r6:85323e41 r5:00000000 r4:40946400 [<805788a0>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfaf9fa8 to 0xdfaf9ff0) 9fa0: 00000000 00000000 00000003 40946400 200000c0 00000000 9fc0: 00000000 00000000 00316308 00000036 00300000 00000000 00006364 76fda0bc 9fe0: 76fd9ec0 76fd9eb0 0001928c 00132970 r10:00000036 r9:85865400 r8:8020029c r7:00000036 r6:00316308 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