linux-kernel - Re: [PATCH V2 2/2] mm/memblock.c: check return value of memblock_reserve() in memblock_virt_alloc

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20161219152156.GC5175@dhcp22.suse.cz>
Date:   Mon, 19 Dec 2016 16:21:57 +0100
From:   Michal Hocko <mhocko@...nel.org>
To:     Wei Yang <richard.weiyang@...il.com>
Cc:     trivial@...nel.org, akpm@...ux-foundation.org, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH V2 2/2] mm/memblock.c: check return value of
 memblock_reserve() in memblock_virt_alloc_internal()

On Sun 18-12-16 14:47:50, Wei Yang wrote:
> memblock_reserve() may fail in case there is not enough regions.

Have you seen this happenning in the real setups or this is a by-review
driven change?
[...]
>  again:
>  	alloc = memblock_find_in_range_node(size, align, min_addr, max_addr,
>  					    nid, flags);
> -	if (alloc)
> +	if (alloc && !memblock_reserve(alloc, size))
>  		goto done;
>  
>  	if (nid != NUMA_NO_NODE) {
>  		alloc = memblock_find_in_range_node(size, align, min_addr,
>  						    max_addr, NUMA_NO_NODE,
>  						    flags);
> -		if (alloc)
> +		if (alloc && !memblock_reserve(alloc, size))
>  			goto done;
>  	}

This doesn't look right. You can end up leaking the first allocated
range.

>  
> @@ -1303,7 +1302,6 @@ static void * __init memblock_virt_alloc_internal(
>  
>  	return NULL;
>  done:
> -	memblock_reserve(alloc, size);
>  	ptr = phys_to_virt(alloc);
>  	memset(ptr, 0, size);


>  
> -- 
> 2.5.0
> 
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@...ck.org.  For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@...ck.org"> email@...ck.org </a>

-- 
Michal Hocko
SUSE Labs