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[v2] netfilter: avoid warn and OOM killer on vmalloc call

Message ID e10fd8b5206bfde5526e3bbf2b5ff9af584b0a6f.1480671893.git.marcelo.leitner@gmail.com
State Awaiting Upstream, archived
Delegated to: David Miller
Headers show

Commit Message

Marcelo Ricardo Leitner Dec. 2, 2016, 9:46 a.m. UTC
Andrey Konovalov reported that this vmalloc call is based on an
userspace request and that it's spewing traces, which may flood the logs
and cause DoS if abused.

Florian Westphal also mentioned that this call should not trigger OOM
killer.

This patch brings the vmalloc call in sync to kmalloc and disables the
warn trace on allocation failure and also disable OOM killer invocation.

Note, however, that under such stress situation, other places may
trigger OOM killer invocation.

Reported-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
---
 net/netfilter/x_tables.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Pablo Neira Ayuso Dec. 6, 2016, 12:21 p.m. UTC | #1
On Fri, Dec 02, 2016 at 07:46:38AM -0200, Marcelo Ricardo Leitner wrote:
> Andrey Konovalov reported that this vmalloc call is based on an
> userspace request and that it's spewing traces, which may flood the logs
> and cause DoS if abused.
> 
> Florian Westphal also mentioned that this call should not trigger OOM
> killer.
> 
> This patch brings the vmalloc call in sync to kmalloc and disables the
> warn trace on allocation failure and also disable OOM killer invocation.
> 
> Note, however, that under such stress situation, other places may
> trigger OOM killer invocation.

Unless anyone has an objection, I'm going to place this in nf-next.

Thanks.

> Reported-by: Andrey Konovalov <andreyknvl@google.com>
> Cc: Florian Westphal <fw@strlen.de>
> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
> ---
>  net/netfilter/x_tables.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
> index fc4977456c30e098197b4f987b758072c9cf60d9..dece525bf83a0098dad607fce665cd0bde228362 100644
> --- a/net/netfilter/x_tables.c
> +++ b/net/netfilter/x_tables.c
> @@ -958,7 +958,9 @@ struct xt_table_info *xt_alloc_table_info(unsigned int size)
>  	if (sz <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER))
>  		info = kmalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
>  	if (!info) {
> -		info = vmalloc(sz);
> +		info = __vmalloc(sz, GFP_KERNEL | __GFP_NOWARN |
> +				     __GFP_NORETRY | __GFP_HIGHMEM,
> +				 PAGE_KERNEL);
>  		if (!info)
>  			return NULL;
>  	}
> -- 
> 2.9.3
>
diff mbox

Patch

diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index fc4977456c30e098197b4f987b758072c9cf60d9..dece525bf83a0098dad607fce665cd0bde228362 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -958,7 +958,9 @@  struct xt_table_info *xt_alloc_table_info(unsigned int size)
 	if (sz <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER))
 		info = kmalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
 	if (!info) {
-		info = vmalloc(sz);
+		info = __vmalloc(sz, GFP_KERNEL | __GFP_NOWARN |
+				     __GFP_NORETRY | __GFP_HIGHMEM,
+				 PAGE_KERNEL);
 		if (!info)
 			return NULL;
 	}