Patch "ila_xlat: add missing hash secret initialization" has been added to the 4.11-stable tree

This is a note to let you know that I've just added the patch titled

ila_xlat: add missing hash secret initialization

to the 4.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
ila_xlat-add-missing-hash-secret-initialization.patch
and it can be found in the queue-4.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Arnd Bergmann <[email protected]>
Date: Thu, 8 Jun 2017 09:54:24 +0200
Subject: ila_xlat: add missing hash secret initialization

From: Arnd Bergmann <[email protected]>

commit 0db47e3d323411beeb6ea97f2c4d19395c91fd8b upstream.

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.

---
 net/ipv6/ila/ila_xlat.c |    1 +
 1 file changed, 1 insertion(+)

@@ -68,6 +68,7 @@ static inline u32 ila_locator_hash(struc
 {
 	u32 *v = (u32 *)loc.v32;
 
+	__ila_hash_secret_init();
 	return jhash_2words(v[0], v[1], hashrnd);
 }
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.11/ila_xlat-add-missing-hash-secret-initialization.patch queue-4.11/pvrusb2-reduce-stack-usage-pvr2_eeprom_analyze.patch