From 0db47e3d323411beeb6ea97f2c4d19395c91fd8b Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 8 Jun 2017 09:54:24 +0200 Subject: [PATCH] ila_xlat: add missing hash secret initialization While discussing the possible merits of clang warning about unused initialized functions, I found one function that was clearly meant to be called but never actually is. __ila_hash_secret_init() initializes the hash value for the ila locator, apparently this is intended to prevent hash collision attacks, but this ends up being a read-only zero constant since there is no caller. I could find no indication of why it was never called, the earliest patch submission for the module already was like this. If my interpretation is right, we certainly want to backport the patch to stable kernels as well. I considered adding it to the ila_xlat_init callback, but for best effect the random data is read as late as possible, just before it is first used. The underlying net_get_random_once() is already highly optimized to avoid overhead when called frequently. Fixes: 7f00feaf1076 ("ila: Add generic ILA translation facility") Cc: stable@vger.kernel.org Link: https://www.spinics.net/lists/kernel/msg2527243.html Signed-off-by: Arnd Bergmann Signed-off-by: David S. Miller --- net/ipv6/ila/ila_xlat.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/ipv6/ila/ila_xlat.c b/net/ipv6/ila/ila_xlat.c index 2fd5ca151dcf..77f7f8c7d93d 100644 --- a/net/ipv6/ila/ila_xlat.c +++ b/net/ipv6/ila/ila_xlat.c @@ -62,6 +62,7 @@ static inline u32 ila_locator_hash(struct ila_locator loc) { u32 *v = (u32 *)loc.v32; + __ila_hash_secret_init(); return jhash_2words(v[0], v[1], hashrnd); } -- 2.20.1