Re: AF_ALG inadvertently disabled

[Tom Lendacky]

On 09/04/2014 07:43 PM, Scot Doyle wrote:

On a laptop without AMD's CCP, compiling 3.17-rc3 with
   # CONFIG_MODULES is not set
   CONFIG_CRYPTO_MANAGER_DISABLE_TESTS=y
   CONFIG_CRYPTO_DEV_CCP=y
   CONFIG_CRYPTO_DEV_CCP_DD=y
   # CONFIG_CRYPTO_DEV_CCP_CRYPTO is not set
the strace from a test program is
   socket(PF_ALG, SOCK_SEQPACKET, 0)       = 3
   bind(3, {sa_family=AF_ALG, sa_data="skcipher\0\0\0\0\0\0"}, 88) = 0
   setsockopt(3, 0x117 /* SOL_?? */, 1, "n) 
\21\220\25-\364\356\5\2019\336\366\20\273", 16) = 0
   accept(3, 0, NULL)                      = 4
   sendmsg(4, {msg_name(0)=NULL, 
msg_iov(1)=[{"\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27"...,
 512}], msg_controllen=64, {cmsg_len=20, cmsg_level=0x117 /* SOL_??? */, cmsg_type=, 
...}, msg_flags=0}, 0) = 512
   read(4, 
"\322\322\22\25\3\3159\2052Q\356\256lA<\336\245\230a\36!\343\366\26=J\231\254\211x>G"...,
 512) = 512


However, when compiling with
   # CONFIG_MODULES is not set
   CONFIG_CRYPTO_MANAGER_DISABLE_TESTS=y
   CONFIG_CRYPTO_DEV_CCP=y
   CONFIG_CRYPTO_DEV_CCP_DD=y
   CONFIG_CRYPTO_DEV_CCP_CRYPTO=y
the strace from the same test program is
   socket(PF_ALG, SOCK_SEQPACKET, 0)       = 3
   bind(3, {sa_family=AF_ALG, sa_data="skcipher\0\0\0\0\0\0"}, 88) = 0
   setsockopt(3, 0x117 /* SOL_?? */, 1, "n) 
\21\220\25-\364\356\5\2019\336\366\20\273", 16) = 0
   accept(3, 0, NULL)                      = 4
   sendmsg(4, {msg_name(0)=NULL, 
msg_iov(1)=[{"\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27\27"...,
 512}], msg_controllen=64, {cmsg_len=20, cmsg_level=0x117 /* SOL_??? */, cmsg_type=, 
...}, msg_flags=0}, 0) = 512
   read(4, 0x1f48000, 512)                 = -1 ENODEV (No such device)

Because ccp-crypto isn't built as a module it will register the
algorithms even if a CCP device isn't there. I'll work up a patch
that checks for the presence of the CCP and only register the
algorithms if a CCP is there.

Thanks,
Tom

cryptsetup exhibits the same behavior as the test program.

--
To unsubscribe from this list: send the line "unsubscribe linux-crypto" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html