8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 00000018 when write [00000018] *pgd=8524e003, *pmd=f2e01003 Internal error: Oops: a07 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 6381 Comm: syz-executor.1 Not tainted 6.9.0-rc1-syzkaller #0 Hardware name: ARM-Versatile Express PC is at pagemap_scan_init_bounce_buffer fs/proc/task_mmu.c:2399 [inline] PC is at do_pagemap_scan+0x294/0x6b4 fs/proc/task_mmu.c:2445 LR is at kmalloc_array include/linux/slab.h:665 [inline] LR is at pagemap_scan_init_bounce_buffer fs/proc/task_mmu.c:2394 [inline] LR is at do_pagemap_scan+0x260/0x6b4 fs/proc/task_mmu.c:2445 pc : [<8059d75c>] lr : [<8059d728>] psr: 20000013 sp : e0069e18 ip : 00000000 fp : e0069f04 r10: e0069e50 r9 : 84a49800 r8 : 00000000 r7 : 00000000 r6 : 00000000 r5 : 20ffc000 r4 : 85105200 r3 : 20ffc000 r2 : 00000000 r1 : 00000000 r0 : 00000010 Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 8516b4c0 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 85105200 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 84a49800 pointer offset 0 size 3072 Register r10 information: 2-page vmalloc region starting at 0xe0068000 allocated at kernel_clone+0xac/0x3cc kernel/fork.c:2796 Register r11 information: 2-page vmalloc region starting at 0xe0068000 allocated at kernel_clone+0xac/0x3cc kernel/fork.c:2796 Register r12 information: NULL pointer Process syz-executor.1 (pid: 6381, stack limit = 0xe0068000) Stack: (0xe0069e18 to 0xe006a000) 9e00: 00000000 00000000 9e20: 06000000 20000900 00000001 00000000 00000000 20ffc000 00000000 00000000 9e40: 00000000 00000000 00000000 00000000 00000060 00000000 00000000 00000000 9e60: 20ffc000 00000000 20ffc000 00000000 00000000 00000000 20000840 00000000 9e80: 00000000 06000000 ffffffff 00000000 00000000 00000000 00000000 00000000 9ea0: 00000000 00000000 00000000 00000000 00000000 00000000 00000010 00000000 9ec0: 00000000 00000000 20000840 00000000 c0606610 d4dc1772 e0069ef4 c0606610 9ee0: 00000000 851d3cc1 20000900 00000003 84a49800 851d3cc0 e0069f14 e0069f08 9f00: 8059dba4 8059d4d4 e0069fa4 e0069f18 8050fbdc 8059db88 84a49800 00000001 9f20: ecac8b10 84a49800 e0069f44 e0069f38 81898230 818980fc e0069f5c e0069f48 9f40: 8024c880 8027b0a4 40000000 e0069fb0 e0069f84 e0069f60 8020316c 8024c83c 9f60: 8261ca0c e0069fb0 0006b3f0 ecac8b10 80203054 d4dc1772 e0069fac 00000000 9f80: 00000000 0014c2c8 00000036 80200288 84a49800 00000036 00000000 e0069fa8 9fa0: 80200060 8050fad0 00000000 00000000 00000003 c0606610 20000900 00000000 9fc0: 00000000 00000000 0014c2c8 00000036 7eb2532e 7eb2532f 003d0f00 76b3b0fc 9fe0: 76b3af08 76b3aef8 000167f8 00050bc0 60000010 00000003 00000000 00000000 Call trace: [<8059d4c8>] (do_pagemap_scan) from [<8059dba4>] (do_pagemap_cmd+0x28/0x34 fs/proc/task_mmu.c:2512) r10:851d3cc0 r9:84a49800 r8:00000003 r7:20000900 r6:851d3cc1 r5:00000000 r4:c0606610 [<8059db7c>] (do_pagemap_cmd) from [<8050fbdc>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<8059db7c>] (do_pagemap_cmd) from [<8050fbdc>] (do_vfs_ioctl fs/ioctl.c:858 [inline]) [<8059db7c>] (do_pagemap_cmd) from [<8050fbdc>] (__do_sys_ioctl fs/ioctl.c:902 [inline]) [<8059db7c>] (do_pagemap_cmd) from [<8050fbdc>] (sys_ioctl+0x118/0xc24 fs/ioctl.c:890) [<8050fac4>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:66) Exception stack(0xe0069fa8 to 0xe0069ff0) 9fa0: 00000000 00000000 00000003 c0606610 20000900 00000000 9fc0: 00000000 00000000 0014c2c8 00000036 7eb2532e 7eb2532f 003d0f00 76b3b0fc 9fe0: 76b3af08 76b3aef8 000167f8 00050bc0 r10:00000036 r9:84a49800 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