4.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Biggers <ebiggers@xxxxxxxxxx>
commit af839b4e546613aed1fbd64def73956aa98631e7 upstream.
There is a copy-paste error where sha256_mb_mgr_get_comp_job_avx2()
copies the SHA-256 digest state from sha256_mb_mgr::args::digest to
job_sha256::result_digest. Consequently, the sha256_mb algorithm
sometimes calculates the wrong digest. Fix it.
Reproducer using AF_ALG:
#include <assert.h>
#include <linux/if_alg.h>
#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <unistd.h>
static const __u8 expected[32] =
"\xad\x7f\xac\xb2\x58\x6f\xc6\xe9\x66\xc0\x04\xd7\xd1\xd1\x6b\x02"
"\x4f\x58\x05\xff\x7c\xb4\x7c\x7a\x85\xda\xbd\x8b\x48\x89\x2c\xa7";
int main()
{
int fd;
struct sockaddr_alg addr = {
.salg_type = "hash",
.salg_name = "sha256_mb",
};
__u8 data[4096] = { 0 };
__u8 digest[32];
int ret;
int i;
fd = socket(AF_ALG, SOCK_SEQPACKET, 0);
bind(fd, (void *)&addr, sizeof(addr));
fork();
fd = accept(fd, 0, 0);
do {
ret = write(fd, data, 4096);
assert(ret == 4096);
ret = read(fd, digest, 32);
assert(ret == 32);
} while (memcmp(digest, expected, 32) == 0);
printf("wrong digest: ");
for (i = 0; i < 32; i++)
printf("%02x", digest[i]);
printf("\n");
}
Output was:
wrong digest: ad7facb2000000000000000000000000ffffffef7cb47c7a85dabd8b48892ca7
Fixes: 172b1d6b5a93 ("crypto: sha256-mb - fix ctx pointer and digest copy")
Cc: <stable@xxxxxxxxxxxxxxx> # v4.8+
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/crypto/sha256-mb/sha256_mb_mgr_flush_avx2.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/crypto/sha256-mb/sha256_mb_mgr_flush_avx2.S
+++ b/arch/x86/crypto/sha256-mb/sha256_mb_mgr_flush_avx2.S
@@ -265,7 +265,7 @@ ENTRY(sha256_mb_mgr_get_comp_job_avx2)
vpinsrd $1, _args_digest+1*32(state, idx, 4), %xmm0, %xmm0
vpinsrd $2, _args_digest+2*32(state, idx, 4), %xmm0, %xmm0
vpinsrd $3, _args_digest+3*32(state, idx, 4), %xmm0, %xmm0
- vmovd _args_digest(state , idx, 4) , %xmm0
+ vmovd _args_digest+4*32(state, idx, 4), %xmm1
vpinsrd $1, _args_digest+5*32(state, idx, 4), %xmm1, %xmm1
vpinsrd $2, _args_digest+6*32(state, idx, 4), %xmm1, %xmm1
vpinsrd $3, _args_digest+7*32(state, idx, 4), %xmm1, %xmm1
