8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 00000018 when write [00000018] *pgd=85246003, *pmd=fe21a003 Internal error: Oops: a07 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 22493 Comm: syz-executor.1 Not tainted 6.8.0-rc6-syzkaller #0 Hardware name: ARM-Versatile Express PC is at pagemap_scan_init_bounce_buffer fs/proc/task_mmu.c:2400 [inline] PC is at do_pagemap_scan+0x29c/0x6c0 fs/proc/task_mmu.c:2446 LR is at kmalloc_array include/linux/slab.h:627 [inline] LR is at pagemap_scan_init_bounce_buffer fs/proc/task_mmu.c:2395 [inline] LR is at do_pagemap_scan+0x268/0x6c0 fs/proc/task_mmu.c:2446 pc : [<8058c938>] lr : [<8058c904>] psr: 20000013 sp : eb095dc8 ip : 00000000 fp : eb095eb4 r10: eb095e00 r9 : 8363e000 r8 : 00000000 r7 : 00000000 r6 : 00000000 r5 : 201c9000 r4 : 85265b00 r3 : 20ffc000 r2 : 00000000 r1 : 00000000 r0 : 00000010 Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 99090d00 DAC: fffffffd Register r0 information: zero-size pointer Register r1 information: NULL pointer Register r2 information: NULL pointer Register r3 information: non-paged memory Register r4 information: slab mm_struct start 85265b00 pointer offset 0 size 712 Register r5 information: non-paged memory Register r6 information: NULL pointer Register r7 information: NULL pointer Register r8 information: NULL pointer Register r9 information: slab task_struct start 8363e000 pointer offset 0 size 3072 Register r10 information: 2-page vmalloc region starting at 0xeb094000 allocated at kernel_clone+0xac/0x3c8 kernel/fork.c:2902 Register r11 information: 2-page vmalloc region starting at 0xeb094000 allocated at kernel_clone+0xac/0x3c8 kernel/fork.c:2902 Register r12 information: NULL pointer Process syz-executor.1 (pid: 22493, stack limit = 0xeb094000) Stack: (0xeb095dc8 to 0xeb096000) 5dc0: 00000000 00000000 06000000 20000140 00000001 00000000 5de0: 00000000 201c9000 00000000 00000000 00000000 00000000 00000000 00000000 5e00: 00000060 00000000 00000000 00000000 201c9000 00000000 20ffc000 00000000 5e20: 00000000 00000000 20000040 00000000 00000000 06000000 ffffffff 00000000 5e40: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 5e60: 00000000 00000000 00000010 00000000 00000000 00000000 20000040 00000000 5e80: c0606610 8058e998 eb095ea4 c0606610 00000000 842c0b41 20000140 842c0b40 5ea0: 00000003 8363e000 eb095ec4 eb095eb8 8058cd84 8058c6a8 eb095fa4 eb095ec8 5ec0: 80502108 8058cd68 00050bb0 00000000 00000000 00000000 eb095f04 eb095ee8 5ee0: 8020c124 8020d0f0 00000000 00000001 81862408 ecac8b10 eb095f44 eb095f08 5f00: 8020d178 8020c10c 000f4240 00000000 8020c9cc eb095fac 8363e000 00000001 5f20: ecac8b10 8363e000 eb095f44 eb095f38 81856d20 81856bf0 eb095f5c eb095f48 5f40: 8024c7e8 802798f0 40000000 eb095fb0 eb095f84 eb095f60 80203134 8024c7a4 5f60: 8261c978 eb095fb0 0006b3e0 ecac8b10 8020301c 8058e998 eb095fac 00000000 5f80: 00000000 0014c2c8 00000036 80200288 8363e000 00000036 00000000 eb095fa8 5fa0: 80200060 80501ffc 00000000 00000000 00000003 c0606610 20000140 00000000 5fc0: 00000000 00000000 0014c2c8 00000036 7ea3232e 7ea3232f 003d0f00 76bf60fc 5fe0: 76bf5f08 76bf5ef8 000167e8 00050bb0 60000010 00000003 00000000 00000000 Backtrace: [<8058c69c>] (do_pagemap_scan) from [<8058cd84>] (do_pagemap_cmd+0x28/0x34 fs/proc/task_mmu.c:2513) r10:8363e000 r9:00000003 r8:842c0b40 r7:20000140 r6:842c0b41 r5:00000000 r4:c0606610 [<8058cd5c>] (do_pagemap_cmd) from [<80502108>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<8058cd5c>] (do_pagemap_cmd) from [<80502108>] (do_vfs_ioctl fs/ioctl.c:831 [inline]) [<8058cd5c>] (do_pagemap_cmd) from [<80502108>] (__do_sys_ioctl fs/ioctl.c:869 [inline]) [<8058cd5c>] (do_pagemap_cmd) from [<80502108>] (sys_ioctl+0x118/0xb58 fs/ioctl.c:857) [<80501ff0>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:66) Exception stack(0xeb095fa8 to 0xeb095ff0) 5fa0: 00000000 00000000 00000003 c0606610 20000140 00000000 5fc0: 00000000 00000000 0014c2c8 00000036 7ea3232e 7ea3232f 003d0f00 76bf60fc 5fe0: 76bf5f08 76bf5ef8 000167e8 00050bb0 r10:00000036 r9:8363e000 r8:80200288 r7:00000036 r6:0014c2c8 r5:00000000 r4:00000000 Code: e51b309c e51b208c e50b203c e3a02000 (e1c060f8) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: e51b309c ldr r3, [fp, #-156] @ 0xffffff64 4: e51b208c ldr r2, [fp, #-140] @ 0xffffff74 8: e50b203c str r2, [fp, #-60] @ 0xffffffc4 c: e3a02000 mov r2, #0 * 10: e1c060f8 strd r6, [r0, #8] <-- trapping instruction