linux-kernel - Re: [PATCH v9 67/69] mm: remove the vma linked list

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20220513133022.GA482@qian>
Date:   Fri, 13 May 2022 09:30:22 -0400
From:   Qian Cai <quic_qiancai@...cinc.com>
To:     Liam Howlett <liam.howlett@...cle.com>
CC:     "maple-tree@...ts.infradead.org" <maple-tree@...ts.infradead.org>,
        "linux-mm@...ck.org" <linux-mm@...ck.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [PATCH v9 67/69] mm: remove the vma linked list

On Wed, May 04, 2022 at 01:14:07AM +0000, Liam Howlett wrote:
...
> @@ -2488,13 +2380,20 @@ do_mas_align_munmap(struct ma_state *mas, struct vm_area_struct *vma,
>  		    struct mm_struct *mm, unsigned long start,
>  		    unsigned long end, struct list_head *uf, bool downgrade)
>  {
> -	struct vm_area_struct *prev, *last;
> +	struct vm_area_struct *prev, *next = NULL;
> +	struct maple_tree mt_detach;
> +	int count = 0;
>  	int error = -ENOMEM;
> -	/* we have start < vma->vm_end  */
> +	MA_STATE(mas_detach, &mt_detach, start, end - 1);
> +	mt_init_flags(&mt_detach, MM_MT_FLAGS);
> +	mt_set_external_lock(&mt_detach, &mm->mmap_lock);
>  
>  	if (mas_preallocate(mas, vma, GFP_KERNEL))
>  		return -ENOMEM;
>  
> +	if (mas_preallocate(&mas_detach, vma, GFP_KERNEL))

This guy was reported as leaks as well.

unreferenced object 0xffff0802d49b5500 (size 256):
  comm "trinity-c22", pid 107245, jiffies 4295674711 (age 816.980s)
  hex dump (first 32 bytes):
    01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
     kmem_cache_alloc
     mas_alloc_nodes
     mas_preallocate
     do_mas_align_munmap.constprop.0
     do_mas_align_munmap at mm/mmap.c:2384
     do_mas_munmap
     __vm_munmap
     __arm64_sys_munmap
     invoke_syscall
     el0_svc_common.constprop.0
     do_el0_svc
     el0_svc
     el0t_64_sync_handler
     el0t_64_sync

> +		return -ENOMEM;
> +
>  	mas->last = end - 1;
>  	/*
>  	 * If we need to split any vma, do it now to save pain later.