The mac_compute() function in openssh calls umac_final() to prepend a tag
to a buffer. Umac_final() calls pdf_gen_xor() on the tag as its final
operation, and as implemented, pdf_gen_xor() assumes an appropriate
alignment for 64-bit operations on its buffer. However, the buffer
is declared in mac_compute() as a static u_char array, and the linker
doesn't guarantee 64-bit alignment for such arrays. On ARM v7 NEON
platforms with gcc, 64-bit values must be 64-bit aligned, and the
unaligned buffer declaration caused alignment faults when executing
certain openssh tests.
Force the buffer in mac_compute() to be 64-bit aligned.
Signed-off-by: Donn Seeley <donn.seeley at windriver.com>
Signed-off-by: Roy Li <rongqing.li at windriver.com>
---
mac.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
--- a/mac.c
+++ b/mac.c
@@ -132,12 +132,14 @@ mac_init(Mac *mac)
u_char *
mac_compute(Mac *mac, u_int32_t seqno, u_char *data, int datalen)
{
- static u_char m[EVP_MAX_MD_SIZE];
+ static u_int64_t m_buf[(EVP_MAX_MD_SIZE + sizeof (u_int64_t) - 1)
+ / sizeof (u_int64_t)];
+ u_char *m = (u_char *)m_buf;
u_char b[4], nonce[8];
- if (mac->mac_len > sizeof(m))
+ if (mac->mac_len > EVP_MAX_MD_SIZE)
fatal("mac_compute: mac too long %u %lu",
- mac->mac_len, (u_long)sizeof(m));
+ mac->mac_len, (u_long)EVP_MAX_MD_SIZE);
switch (mac->type) {
case SSH_EVP: