diff options
| author | Eric Dumazet <edumazet@google.com> | 2016-06-27 18:51:53 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-07-01 04:02:55 -0400 |
| commit | 19689e38eca5d7b32755182d4e62efd7a5376c45 (patch) | |
| tree | bf400027c33a83030519e00b0c391e61e29a5566 /net/ipv4/tcp.c | |
| parent | 435c556cde6096c2035207a5dceef1d99da51d01 (diff) | |
| download | linux-19689e38eca5d7b32755182d4e62efd7a5376c45.tar.gz linux-19689e38eca5d7b32755182d4e62efd7a5376c45.tar.xz | |
tcp: md5: use kmalloc() backed scratch areas
Some arches have virtually mapped kernel stacks, or will soon have.
tcp_md5_hash_header() uses an automatic variable to copy tcp header
before mangling th->check and calling crypto function, which might
be problematic on such arches.
David says that using percpu storage is also problematic on non SMP
builds.
Just use kmalloc() to allocate scratch areas.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp.c')
| -rw-r--r-- | net/ipv4/tcp.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 108ef2a6665c..032a96d78c99 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3026,8 +3026,18 @@ static void __tcp_alloc_md5sig_pool(void) return; for_each_possible_cpu(cpu) { + void *scratch = per_cpu(tcp_md5sig_pool, cpu).scratch; struct ahash_request *req; + if (!scratch) { + scratch = kmalloc_node(sizeof(union tcp_md5sum_block) + + sizeof(struct tcphdr), + GFP_KERNEL, + cpu_to_node(cpu)); + if (!scratch) + return; + per_cpu(tcp_md5sig_pool, cpu).scratch = scratch; + } if (per_cpu(tcp_md5sig_pool, cpu).md5_req) continue; |