8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 00000018 when write [00000018] *pgd=974bc003, *pmd=fe7e6003 Internal error: Oops: a07 [#1] PREEMPT SMP ARM Modules linked in: CPU: 1 PID: 5750 Comm: syz-executor.1 Not tainted 6.7.0-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 : [<8058c730>] lr : [<8058c6fc>] psr: 20000013 sp : ec655dc8 ip : 00000000 fp : ec655eb4 r10: ec655e00 r9 : 85120000 r8 : 00000000 r7 : 00000000 r6 : 00000000 r5 : 20ffc000 r4 : 84f45b00 r3 : 20ffd000 r2 : 00000000 r1 : 00000000 r0 : 00000010 Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 850fb9c0 DAC: 00000000 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 84f45b00 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 85120000 pointer offset 0 size 3072 Register r10 information: 2-page vmalloc region starting at 0xec654000 allocated at kernel_clone+0xac/0x3c8 kernel/fork.c:2901 Register r11 information: 2-page vmalloc region starting at 0xec654000 allocated at kernel_clone+0xac/0x3c8 kernel/fork.c:2901 Register r12 information: NULL pointer Process syz-executor.1 (pid: 5750, stack limit = 0xec654000) Stack: (0xec655dc8 to 0xec656000) 5dc0: 00000000 00000000 00010000 20000140 00000001 00000000 5de0: 00000000 20ffc000 00000000 00000000 00000000 00000000 00000000 00000000 5e00: 00000060 00000000 00000000 00000000 20ffc000 00000000 20ffd000 00000000 5e20: 00000000 00000000 20000080 00000000 00000000 00010000 ffffffff 00000000 5e40: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 5e60: 00000000 00000000 00000010 00000000 00000000 00000000 20000080 00000000 5e80: c0606610 9387b302 ec655ea4 c0606610 00000000 843b49c1 20000140 843b49c0 5ea0: 00000003 85120000 ec655ec4 ec655eb8 8058cb7c 8058c4a0 ec655fa4 ec655ec8 5ec0: 80501ebc 8058cb60 00050bd0 00000000 00000000 00000000 ec655f04 ec655ee8 5ee0: 8020c124 8020d0f0 00000000 00000001 8185fa80 ecac8b10 ec655f44 ec655f08 5f00: 8020d178 8020c10c 00000000 00000000 8020c9cc ec655fac 85120000 00000001 5f20: ecac8b10 85120000 ec655f44 ec655f38 818543f8 818542c8 ec655f5c ec655f48 5f40: 8024c824 80279930 40000000 ec655fb0 ec655f84 ec655f60 80203134 8024c7e0 5f60: 8261c978 ec655fb0 0006b400 ecac8b10 8020301c 9387b302 ec655fac 00000000 5f80: 00000000 0014c2c8 00000036 80200288 85120000 00000036 00000000 ec655fa8 5fa0: 80200060 80501db0 00000000 00000000 00000003 c0606610 20000140 00000000 5fc0: 00000000 00000000 0014c2c8 00000036 7eb66326 7eb66327 003d0f00 76b8b0fc 5fe0: 76b8af08 76b8aef8 000167e8 00050bd0 60000010 00000003 00000000 00000000 Backtrace: [<8058c494>] (do_pagemap_scan) from [<8058cb7c>] (do_pagemap_cmd+0x28/0x34 fs/proc/task_mmu.c:2513) r10:85120000 r9:00000003 r8:843b49c0 r7:20000140 r6:843b49c1 r5:00000000 r4:c0606610 [<8058cb54>] (do_pagemap_cmd) from [<80501ebc>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<8058cb54>] (do_pagemap_cmd) from [<80501ebc>] (do_vfs_ioctl fs/ioctl.c:831 [inline]) [<8058cb54>] (do_pagemap_cmd) from [<80501ebc>] (__do_sys_ioctl fs/ioctl.c:869 [inline]) [<8058cb54>] (do_pagemap_cmd) from [<80501ebc>] (sys_ioctl+0x118/0xb58 fs/ioctl.c:857) [<80501da4>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:66) Exception stack(0xec655fa8 to 0xec655ff0) 5fa0: 00000000 00000000 00000003 c0606610 20000140 00000000 5fc0: 00000000 00000000 0014c2c8 00000036 7eb66326 7eb66327 003d0f00 76b8b0fc 5fe0: 76b8af08 76b8aef8 000167e8 00050bd0 r10:00000036 r9:85120000 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