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  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]
Date:	Wed, 22 Oct 2014 19:38:31 -0400
From:	Jonathan Toppins <jtoppins@...ulusnetworks.com>
To:	Crestez Dan Leonard <cdleonard@...il.com>, netdev@...r.kernel.org
Subject: Re: [RFC] tcp md5 use of alloc_percpu

On 10/22/14, 2:55 PM, Crestez Dan Leonard wrote:
> sg_init_one does virt_addr on the pointer which assumes it is directly accessible. But the tcp_md5sig_pool pointer comes from alloc_percpu which can return memory from the vmalloc area after the pcpu_first_chunk is exhausted. This looks wrong to me. I'm am getting crashes on mips and I believe this to be the cause.

Thinking about this more if the issue really is sg_init_one assumes a
directly accessible memory region, can we just modify the zone
allocation to GFP_DMA using alloc_percpu_gfp()? Does this satisfy the
assumptions made by sg_init_one?

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 1bec4e7..6924320 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2889,7 +2889,7 @@ static void __tcp_alloc_md5sig_pool(void)
        int cpu;
        struct tcp_md5sig_pool __percpu *pool;

-       pool = alloc_percpu(struct tcp_md5sig_pool);
+       pool = alloc_percpu_gfp(struct tcp_md5sig_pool, GFP_DMA);
        if (!pool)
                return;



--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Powered by blists - more mailing lists