6.15-stable review patch. If anyone has any objections, please let me know.
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From: David Howells dhowells@redhat.com
[ Upstream commit eed848871c96d4b5a7b06307755b75abd0cc7a06 ]
The recent patch to make the rfc3961 simplified code use sg_miter rather than manually walking the scatterlist to hash the contents of a buffer described by that scatterlist failed to take the starting offset into account.
This is indicated by the selftests reporting:
krb5: Running aes128-cts-hmac-sha256-128 mic krb5: !!! TESTFAIL crypto/krb5/selftest.c:446 krb5: MIC mismatch
Fix this by calling sg_miter_skip() before doing the loop to advance by the offset.
This only affects packet signing modes and not full encryption in RxGK because, for full encryption, the message digest is handled inside the authenc and krb5enc drivers.
Note: Nothing in linus/master uses the krb5lib, though the bug is there. It is used by AF_RXRPC's RxGK implementation in -next, no need to backport.
Fixes: da6f9bf40ac2 ("crypto: krb5 - Use SG miter instead of doing it by hand") Reported-by: Marc Dionne marc.dionne@auristor.com Signed-off-by: David Howells dhowells@redhat.com cc: Chuck Lever chuck.lever@oracle.com cc: Simon Horman horms@kernel.org cc: linux-afs@lists.infradead.org Acked-by: Herbert Xu herbert@gondor.apana.org.au Link: https://patch.msgid.link/3824017.1745835726@warthog.procyon.org.uk Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- crypto/krb5/rfc3961_simplified.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/crypto/krb5/rfc3961_simplified.c b/crypto/krb5/rfc3961_simplified.c index 79180d28baa9f..e49cbdec7c404 100644 --- a/crypto/krb5/rfc3961_simplified.c +++ b/crypto/krb5/rfc3961_simplified.c @@ -89,6 +89,7 @@ int crypto_shash_update_sg(struct shash_desc *desc, struct scatterlist *sg,
sg_miter_start(&miter, sg, sg_nents(sg), SG_MITER_FROM_SG | SG_MITER_LOCAL); + sg_miter_skip(&miter, offset); for (i = 0; i < len; i += n) { sg_miter_next(&miter); n = min(miter.length, len - i);