linux-kernel - Re: [git pull] vfs.git bits and pieces

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: <1384986285.2164.19.camel@joe-AO722>
Date:	Wed, 20 Nov 2013 14:24:45 -0800
From:	Joe Perches <joe@...ches.com>
To:	Al Viro <viro@...IV.linux.org.uk>
Cc:	Linus Torvalds <torvalds@...ux-foundation.org>,
	linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org,
	"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
Subject: Re: [git pull] vfs.git bits and pieces

On Wed, 2013-11-20 at 22:16 +0000, Al Viro wrote:
> While digging in the same area:
> 
> Wrong page freed on preallocate_pmds() failure exit
> 
> Note that pmds[i] is simply uninitialized at that point...
> Granted, it's very hard to hit (you need split page locks
> *and* kmalloc(sizeof(spinlock_t), GFP_KERNEL) failing),
> but the code is obviously bogus.
> 
> Signed-off-by: Al Viro <viro@...iv.linux.org.uk>
> ---
> diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
> index a7cccb6d..36aa999 100644
> --- a/arch/x86/mm/pgtable.c
> +++ b/arch/x86/mm/pgtable.c
> @@ -209,7 +209,7 @@ static int preallocate_pmds(pmd_t *pmds[])
>  		if (!pmd)
>  			failed = true;
>  		if (pmd && !pgtable_pmd_page_ctor(virt_to_page(pmd))) {
> -			free_page((unsigned long)pmds[i]);
> +			free_page((unsigned long)pmd);
>  			pmd = NULL;
>  			failed = true;
>  		}

trivia: It'd probably read better with an else too

		if (!pmd) {
			failed = true;
		} else if (!pgtable_pmd_page_ctor(virt_to_page(pmd))) {
			etc...

> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@...r.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/