8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 00000018 when write [00000018] *pgd=843d7003, *pmd=fe66c003 Internal error: Oops: a05 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 9335 Comm: syz-executor.1 Not tainted 6.10.0-rc4-syzkaller #0 Hardware name: ARM-Versatile Express PC is at pagemap_scan_init_bounce_buffer fs/proc/task_mmu.c:2414 [inline] PC is at do_pagemap_scan+0x2ac/0x6f8 fs/proc/task_mmu.c:2460 LR is at kmalloc_noprof include/linux/slab.h:664 [inline] LR is at kmalloc_array_noprof include/linux/slab.h:699 [inline] LR is at pagemap_scan_init_bounce_buffer fs/proc/task_mmu.c:2409 [inline] LR is at do_pagemap_scan+0x278/0x6f8 fs/proc/task_mmu.c:2460 pc : [<805a74c4>] lr : [<805a7490>] psr: 20000013 sp : df9a9e18 ip : df9a9e18 fp : df9a9f04 r10: 00000000 r9 : 00000000 r8 : 00000000 r7 : df9a9e50 r6 : 85052400 r5 : 20165000 r4 : 8435f000 r3 : 20ffb000 r2 : 00000000 r1 : 00000000 r0 : 00000010 Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 84fc1e40 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 8435f000 pointer offset 0 size 712 Register r5 information: non-paged memory Register r6 information: slab task_struct start 85052400 pointer offset 0 size 3072 Register r7 information: 2-page vmalloc region starting at 0xdf9a8000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2797 Register r8 information: NULL pointer Register r9 information: NULL pointer Register r10 information: NULL pointer Register r11 information: 2-page vmalloc region starting at 0xdf9a8000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2797 Register r12 information: 2-page vmalloc region starting at 0xdf9a8000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2797 Process syz-executor.1 (pid: 9335, stack limit = 0xdf9a8000) Stack: (0xdf9a9e18 to 0xdf9aa000) 9e00: 00000000 00000000 9e20: 00000000 00000000 200004c0 00000001 20165000 00000000 00000000 00000000 9e40: 00000000 00000000 00000000 00000000 00000060 00000000 00000000 00000000 9e60: 20165000 00000000 20ffb000 00000000 00000000 00000000 20000000 00000000 9e80: 00000000 10000000 ffffffff 00000000 00000000 00000000 00000000 00000000 9ea0: 00000000 00000000 00000000 00000000 00000000 00000000 00000010 00000000 9ec0: 00000000 00000000 20000000 00000000 c0606610 2407eaa6 df9a9ef4 c0606610 9ee0: 00000000 843df6c1 200004c0 843df6c0 00000005 85052400 df9a9f14 df9a9f08 9f00: 805a7938 805a7224 df9a9fa4 df9a9f18 8051a27c 805a791c 85052400 00000001 9f20: ecac8b10 85052400 df9a9f44 df9a9f38 818f377c 818f364c df9a9f5c df9a9f48 9f40: 8024d2c4 8027cc04 40000000 df9a9fb0 df9a9f84 df9a9f60 80202dc4 8024d280 9f60: 8261c90c df9a9fb0 0006bf00 ecac8b10 80202cac 2407eaa6 df9a9fac 00000000 9f80: 00000000 00154358 00000036 8020029c 85052400 00000036 00000000 df9a9fa8 9fa0: 80200060 8051a154 00000000 00000000 00000005 c0606610 200004c0 00000000 9fc0: 00000000 00000000 00154358 00000036 7e80d336 7e80d337 003d0f00 76aec0fc 9fe0: 76aebf08 76aebef8 00016f30 000516d0 60000010 00000005 00000000 00000000 Call trace: [<805a7218>] (do_pagemap_scan) from [<805a7938>] (do_pagemap_cmd+0x28/0x34 fs/proc/task_mmu.c:2527) r10:85052400 r9:00000005 r8:843df6c0 r7:200004c0 r6:843df6c1 r5:00000000 r4:c0606610 [<805a7910>] (do_pagemap_cmd) from [<8051a27c>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<805a7910>] (do_pagemap_cmd) from [<8051a27c>] (do_vfs_ioctl fs/ioctl.c:861 [inline]) [<805a7910>] (do_pagemap_cmd) from [<8051a27c>] (__do_sys_ioctl fs/ioctl.c:905 [inline]) [<805a7910>] (do_pagemap_cmd) from [<8051a27c>] (sys_ioctl+0x134/0xda4 fs/ioctl.c:893) [<8051a148>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdf9a9fa8 to 0xdf9a9ff0) 9fa0: 00000000 00000000 00000005 c0606610 200004c0 00000000 9fc0: 00000000 00000000 00154358 00000036 7e80d336 7e80d337 003d0f00 76aec0fc 9fe0: 76aebf08 76aebef8 00016f30 000516d0 r10:00000036 r9:85052400 r8:8020029c r7:00000036 r6:00154358 r5:00000000 r4:00000000 Code: e51b309c e51b108c e50b103c e3a01000 (e1c080f8) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: e51b309c ldr r3, [fp, #-156] @ 0xffffff64 4: e51b108c ldr r1, [fp, #-140] @ 0xffffff74 8: e50b103c str r1, [fp, #-60] @ 0xffffffc4 c: e3a01000 mov r1, #0 * 10: e1c080f8 strd r8, [r0, #8] <-- trapping instruction