8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 00000018 when write [00000018] *pgd=9781a003, *pmd=ef687003 Internal error: Oops: a07 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 17466 Comm: syz-executor.1 Not tainted 6.8.0-rc1-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 : [<8058c878>] lr : [<8058c844>] psr: 20000013 sp : e0775dc8 ip : 00000000 fp : e0775eb4 r10: e0775e00 r9 : 97a51800 r8 : 00000000 r7 : 00000000 r6 : 00000000 r5 : 20ffd000 r4 : 847e1500 r3 : 20fff000 r2 : 00000000 r1 : 00000000 r0 : 00000010 Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 9781c980 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 847e1500 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 97a51800 pointer offset 0 size 3072 Register r10 information: 2-page vmalloc region starting at 0xe0774000 allocated at kernel_clone+0xac/0x3c8 kernel/fork.c:2902 Register r11 information: 2-page vmalloc region starting at 0xe0774000 allocated at kernel_clone+0xac/0x3c8 kernel/fork.c:2902 Register r12 information: NULL pointer Process syz-executor.1 (pid: 17466, stack limit = 0xe0774000) Stack: (0xe0775dc8 to 0xe0776000) 5dc0: 00000000 00000000 10000000 20000200 00000001 00000000 5de0: 00000000 20ffd000 00000000 00000000 00000000 00000000 00000000 00000000 5e00: 00000060 00000000 00000000 00000000 20ffd000 00000000 20fff000 00000000 5e20: 00000000 00000000 20000100 00000000 00000000 10000000 ffffffff 00000000 5e40: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 5e60: 00000000 00000000 00000010 00000000 00000000 00000000 20000100 00000000 5e80: c0606610 87a93ded e0775ea4 c0606610 00000000 850a4601 20000200 850a4600 5ea0: 00000003 97a51800 e0775ec4 e0775eb8 8058ccc4 8058c5e8 e0775fa4 e0775ec8 5ec0: 80502000 8058cca8 00050bd0 00000000 00000000 00000000 e0775f04 e0775ee8 5ee0: 8020c124 8020d0f0 00000000 00000001 81860760 ecac8b10 e0775f44 e0775f08 5f00: 8020d178 8020c10c 00000000 00000000 8020c9cc e0775fac 97a51800 00000001 5f20: ecac8b10 97a51800 e0775f44 e0775f38 818550d8 81854fa8 e0775f5c e0775f48 5f40: 8024c824 80279930 40000000 e0775fb0 e0775f84 e0775f60 80203134 8024c7e0 5f60: 8261c978 e0775fb0 0006b400 ecac8b10 8020301c 87a93ded e0775fac 00000000 5f80: 00000000 0014c2c8 00000036 80200288 97a51800 00000036 00000000 e0775fa8 5fa0: 80200060 80501ef4 00000000 00000000 00000003 c0606610 20000200 00000000 5fc0: 00000000 00000000 0014c2c8 00000036 7ef67326 7ef67327 003d0f00 76bd00fc 5fe0: 76bcff08 76bcfef8 000167e8 00050bd0 60000010 00000003 00000000 00000000 Backtrace: [<8058c5dc>] (do_pagemap_scan) from [<8058ccc4>] (do_pagemap_cmd+0x28/0x34 fs/proc/task_mmu.c:2513) r10:97a51800 r9:00000003 r8:850a4600 r7:20000200 r6:850a4601 r5:00000000 r4:c0606610 [<8058cc9c>] (do_pagemap_cmd) from [<80502000>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<8058cc9c>] (do_pagemap_cmd) from [<80502000>] (do_vfs_ioctl fs/ioctl.c:831 [inline]) [<8058cc9c>] (do_pagemap_cmd) from [<80502000>] (__do_sys_ioctl fs/ioctl.c:869 [inline]) [<8058cc9c>] (do_pagemap_cmd) from [<80502000>] (sys_ioctl+0x118/0xb58 fs/ioctl.c:857) [<80501ee8>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:66) Exception stack(0xe0775fa8 to 0xe0775ff0) 5fa0: 00000000 00000000 00000003 c0606610 20000200 00000000 5fc0: 00000000 00000000 0014c2c8 00000036 7ef67326 7ef67327 003d0f00 76bd00fc 5fe0: 76bcff08 76bcfef8 000167e8 00050bd0 r10:00000036 r9:97a51800 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