See https://github.com/NixOS/nixpkgs/issues/6231

v3.14.31:crypto/crc32c.c is missing the MODULE_ALIAS_CRYPTO("crc32c").
That's probably because crypto/crc32c.c was renamed to
crypto/crc32c_generic.c in commit
06e5a1f29819759392239669beb2cad27059c8ec and therefore fell through
the cracks when backporting commit
5d26a105b5a73e5635eae0629b42fa0a90e07b7b.

So the affected kernels (all that backported the "crypto-" prefix
patches) need this additional patch:

diff --git a/crypto/crc32c.c b/crypto/crc32c.c
index 06f7018c9d95..aae5829eb681 100644
--- a/crypto/crc32c.c
+++ b/crypto/crc32c.c
@@ -167,6 +167,7 @@ static void __exit crc32c_mod_fini(void)
 module_init(crc32c_mod_init);
 module_exit(crc32c_mod_fini);

+MODULE_ALIAS_CRYPTO("crc32c");
 MODULE_AUTHOR("Clay Haapala <chaapala@cisco.com>");
 MODULE_DESCRIPTION("CRC32c (Castagnoli) calculations wrapper for lib/crc32c");
 MODULE_LICENSE("GPL");