8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 00000008 when read [00000008] *pgd=8438d003, *pmd=f30e4003 Internal error: Oops: 205 [#1] PREEMPT SMP ARM Modules linked in: CPU: 1 PID: 6562 Comm: syz.0.522 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 : [<80539bb4>] lr : [<8054c358>] psr: 80000013 sp : dfa11e80 ip : 84101800 fp : dfa11ec4 r10: 84101800 r9 : 00000003 r8 : 85130000 r7 : 82caa250 r6 : 84101800 r5 : 00000000 r4 : 8514bb68 r3 : dfa11ecc r2 : 00000008 r1 : 82c95800 r0 : 00000008 Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 850fe580 DAC: 00000000 Register r0 information: non-paged memory Register r1 information: slab kmalloc-1k start 82c95800 pointer offset 0 size 1024 Register r2 information: non-paged memory Register r3 information: 2-page vmalloc region starting at 0xdfa10000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2777 Register r4 information: slab anon_vma_chain start 8514bb68 pointer offset 0 size 40 Register r5 information: NULL pointer Register r6 information: slab task_struct start 84101800 pointer offset 0 size 3072 Register r7 information: slab mnt_cache start 82caa240 pointer offset 16 size 184 Register r8 information: slab filp start 85130000 pointer offset 0 size 160 Register r9 information: non-paged memory Register r10 information: slab task_struct start 84101800 pointer offset 0 size 3072 Register r11 information: 2-page vmalloc region starting at 0xdfa10000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2777 Register r12 information: slab task_struct start 84101800 pointer offset 0 size 3072 Process syz.0.522 (pid: 6562, stack limit = 0xdfa10000) Stack: (0xdfa11e80 to 0xdfa12000) 1e80: 80551244 84101800 dfa11ebc dfa11e98 8027ca9c 802ac75c 00000000 8514bb68 1ea0: 00000000 84101800 84105080 85130000 00000003 84101800 dfa11ef4 dfa11ec8 1ec0: 8054c358 80539ba4 dfa11ef4 00000000 00000000 afb0116a 8514bb68 8514bb68 1ee0: 84104800 00000008 dfa11f14 dfa11ef8 8055137c 8054c320 0000ff08 00000000 1f00: 85130001 00000000 dfa11fa4 dfa11f18 80519474 80551204 84101800 00000001 1f20: ecac8b10 84101800 dfa11f44 dfa11f38 818f6ee0 818f6db0 dfa11f5c dfa11f48 1f40: 8024b7e4 8027b09c 40000000 dfa11fb0 dfa11f84 dfa11f60 80202dc4 8024b7a0 1f60: 8261c90c dfa11fb0 0014a9d0 ecac8b10 80202cac afb0116a dfa11fac 00000000 1f80: 00000000 002642dc 00000036 8020029c 84101800 00000036 00000000 dfa11fa8 1fa0: 80200060 8051934c 00000000 00000000 00000003 0000ff08 00000000 00000000 1fc0: 00000000 00000000 002642dc 00000036 7e8f4766 7e8f4767 003d0f00 76b060bc 1fe0: 76b05ec8 76b05eb8 00018394 00130520 60000010 00000003 00000000 00000000 Call trace: [<80539b98>] (path_from_stashed) from [<8054c358>] (open_namespace+0x44/0xbc fs/nsfs.c:102) r10:84101800 r9:00000003 r8:85130000 r7:84105080 r6:84101800 r5:00000000 r4:8514bb68 [<8054c314>] (open_namespace) from [<8055137c>] (pidfd_ioctl+0x184/0x4c4 fs/pidfs.c:196) r6:00000008 r5:84104800 r4:8514bb68 [<805511f8>] (pidfd_ioctl) from [<80519474>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<805511f8>] (pidfd_ioctl) from [<80519474>] (do_vfs_ioctl fs/ioctl.c:861 [inline]) [<805511f8>] (pidfd_ioctl) from [<80519474>] (__do_sys_ioctl fs/ioctl.c:905 [inline]) [<805511f8>] (pidfd_ioctl) from [<80519474>] (sys_ioctl+0x134/0xda4 fs/ioctl.c:893) r7:00000000 r6:85130001 r5:00000000 r4:0000ff08 [<80519340>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfa11fa8 to 0xdfa11ff0) 1fa0: 00000000 00000000 00000003 0000ff08 00000000 00000000 1fc0: 00000000 00000000 002642dc 00000036 7e8f4766 7e8f4767 003d0f00 76b060bc 1fe0: 76b05ec8 76b05eb8 00018394 00130520 r10:00000036 r9:84101800 r8:8020029c r7:00000036 r6:002642dc 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