8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 00000008 when read [00000008] *pgd=85212003, *pmd=fe946003 Internal error: Oops: 205 [#1] PREEMPT SMP ARM Modules linked in: CPU: 1 UID: 0 PID: 9363 Comm: syz.1.1240 Not tainted 6.10.0-syzkaller #0 Hardware name: ARM-Versatile Express PC is at path_from_stashed+0x1c/0x308 fs/libfs.c:2204 LR is at open_namespace+0x44/0xbc fs/nsfs.c:102 pc : [<8053a974>] lr : [<8054d110>] psr: 80000013 sp : e03c9e80 ip : 84f10c00 fp : e03c9ec4 r10: 84f10c00 r9 : 00000004 r8 : 85641780 r7 : 82cab250 r6 : 84f10c00 r5 : 00000000 r4 : 8558a4b0 r3 : e03c9ecc r2 : 00000008 r1 : 82c99800 r0 : 00000008 Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 8501fc00 DAC: 00000000 Register r0 information: non-paged memory Register r1 information: slab kmalloc-1k start 82c99800 pointer offset 0 size 1024 Register r2 information: non-paged memory Register r3 information: 2-page vmalloc region starting at 0xe03c8000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2781 Register r4 information: slab anon_vma_chain start 8558a4b0 pointer offset 0 size 40 Register r5 information: NULL pointer Register r6 information: slab task_struct start 84f10c00 pointer offset 0 size 3072 Register r7 information: slab mnt_cache start 82cab240 pointer offset 16 size 184 Register r8 information: slab filp start 85641780 pointer offset 0 size 160 Register r9 information: non-paged memory Register r10 information: slab task_struct start 84f10c00 pointer offset 0 size 3072 Register r11 information: 2-page vmalloc region starting at 0xe03c8000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2781 Register r12 information: slab task_struct start 84f10c00 pointer offset 0 size 3072 Process syz.1.1240 (pid: 9363, stack limit = 0xe03c8000) Stack: (0xe03c9e80 to 0xe03ca000) 9e80: 80552000 84f10c00 e03c9ebc e03c9e98 8027c9dc 802ac4a4 00000000 8558a4b0 9ea0: 00000000 84f10c00 855aa080 85641780 00000004 84f10c00 e03c9ef4 e03c9ec8 9ec0: 8054d110 8053a964 e03c9ef4 00000000 00000000 f50507f3 8558a4b0 8558a4b0 9ee0: 855a9800 00000008 e03c9f14 e03c9ef8 80552138 8054d0d8 0000ff08 00000000 9f00: 85641781 00000000 e03c9fa4 e03c9f18 8051a210 80551fc0 84f10c00 00000001 9f20: ecac8b10 84f10c00 e03c9f44 e03c9f38 8190dda0 8190dc70 e03c9f5c e03c9f48 9f40: 8024b594 8027af5c 40000000 e03c9fb0 e03c9f84 e03c9f60 80202dd8 8024b550 9f60: 8261c90c e03c9fb0 0014ab60 ecac8b10 80202cc0 f50507f3 e03c9fac 00000000 9f80: 00000000 002662dc 00000036 8020029c 84f10c00 00000036 00000000 e03c9fa8 9fa0: 80200060 8051a0e8 00000000 00000000 00000004 0000ff08 00000000 00000000 9fc0: 00000000 00000000 002662dc 00000036 7eea9766 7eea9767 003d0f00 76bd30bc 9fe0: 76bd2ec8 76bd2eb8 00018444 001306b0 60000010 00000004 00000000 00000000 Call trace: [<8053a958>] (path_from_stashed) from [<8054d110>] (open_namespace+0x44/0xbc fs/nsfs.c:102) r10:84f10c00 r9:00000004 r8:85641780 r7:855aa080 r6:84f10c00 r5:00000000 r4:8558a4b0 [<8054d0cc>] (open_namespace) from [<80552138>] (pidfd_ioctl+0x184/0x4c4 fs/pidfs.c:196) r6:00000008 r5:855a9800 r4:8558a4b0 [<80551fb4>] (pidfd_ioctl) from [<8051a210>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<80551fb4>] (pidfd_ioctl) from [<8051a210>] (do_vfs_ioctl fs/ioctl.c:861 [inline]) [<80551fb4>] (pidfd_ioctl) from [<8051a210>] (__do_sys_ioctl fs/ioctl.c:905 [inline]) [<80551fb4>] (pidfd_ioctl) from [<8051a210>] (sys_ioctl+0x134/0xda4 fs/ioctl.c:893) r7:00000000 r6:85641781 r5:00000000 r4:0000ff08 [<8051a0dc>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xe03c9fa8 to 0xe03c9ff0) 9fa0: 00000000 00000000 00000004 0000ff08 00000000 00000000 9fc0: 00000000 00000000 002662dc 00000036 7eea9766 7eea9767 003d0f00 76bd30bc 9fe0: 76bd2ec8 76bd2eb8 00018444 001306b0 r10:00000036 r9:84f10c00 r8:8020029c r7:00000036 r6:002662dc r5:00000000 r4:00000000 Code: e24dd01c e1a07001 e5911004 ee1dcf70 (e5905000) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: e24dd01c sub sp, sp, #28 4: e1a07001 mov r7, r1 8: e5911004 ldr r1, [r1, #4] c: ee1dcf70 mrc 15, 0, ip, cr13, cr0, {3} * 10: e5905000 ldr r5, [r0] <-- trapping instruction