4.4-stable review patch. If anyone has any objections, please let me know.
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From: Yuchung Cheng ycheng@google.com
[ Upstream commit c860e997e9170a6d68f9d1e6e2cf61f572191aaf ]
Fast Open key could be stored in different endian based on the CPU. Previously hosts in different endianness in a server farm using the same key config (sysctl value) would produce different cookies. This patch fixes it by always storing it as little endian to keep same API for LE hosts.
Reported-by: Daniele Iamartino danielei@google.com Signed-off-by: Yuchung Cheng ycheng@google.com Signed-off-by: Eric Dumazet edumazet@google.com Signed-off-by: Neal Cardwell ncardwell@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv4/sysctl_net_ipv4.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-)
--- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -213,8 +213,9 @@ static int proc_tcp_fastopen_key(struct { struct ctl_table tbl = { .maxlen = (TCP_FASTOPEN_KEY_LENGTH * 2 + 10) }; struct tcp_fastopen_context *ctxt; - int ret; u32 user_key[4]; /* 16 bytes, matching TCP_FASTOPEN_KEY_LENGTH */ + __le32 key[4]; + int ret, i;
tbl.data = kmalloc(tbl.maxlen, GFP_KERNEL); if (!tbl.data) @@ -223,11 +224,14 @@ static int proc_tcp_fastopen_key(struct rcu_read_lock(); ctxt = rcu_dereference(tcp_fastopen_ctx); if (ctxt) - memcpy(user_key, ctxt->key, TCP_FASTOPEN_KEY_LENGTH); + memcpy(key, ctxt->key, TCP_FASTOPEN_KEY_LENGTH); else - memset(user_key, 0, sizeof(user_key)); + memset(key, 0, sizeof(key)); rcu_read_unlock();
+ for (i = 0; i < ARRAY_SIZE(key); i++) + user_key[i] = le32_to_cpu(key[i]); + snprintf(tbl.data, tbl.maxlen, "%08x-%08x-%08x-%08x", user_key[0], user_key[1], user_key[2], user_key[3]); ret = proc_dostring(&tbl, write, buffer, lenp, ppos); @@ -243,12 +247,16 @@ static int proc_tcp_fastopen_key(struct * first invocation of tcp_fastopen_cookie_gen */ tcp_fastopen_init_key_once(false); - tcp_fastopen_reset_cipher(user_key, TCP_FASTOPEN_KEY_LENGTH); + + for (i = 0; i < ARRAY_SIZE(user_key); i++) + key[i] = cpu_to_le32(user_key[i]); + + tcp_fastopen_reset_cipher(key, TCP_FASTOPEN_KEY_LENGTH); }
bad_key: pr_debug("proc FO key set 0x%x-%x-%x-%x <- 0x%s: %u\n", - user_key[0], user_key[1], user_key[2], user_key[3], + user_key[0], user_key[1], user_key[2], user_key[3], (char *)tbl.data, ret); kfree(tbl.data); return ret;