[PATCH 3.18 18/28] crypto: x86/sha1-mb - fix panic due to unaligned access

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

3.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andrey Ryabinin <aryabinin@virtuozzo.com>

commit d041b557792c85677f17e08eee535eafbd6b9aa2 upstream.

struct sha1_ctx_mgr allocated in sha1_mb_mod_init() via kzalloc()
and later passed in sha1_mb_flusher_mgr_flush_avx2() function where
instructions vmovdqa used to access the struct. vmovdqa requires
16-bytes aligned argument, but nothing guarantees that struct
sha1_ctx_mgr will have that alignment. Unaligned vmovdqa will
generate GP fault.

Fix this by replacing vmovdqa with vmovdqu which doesn't have alignment
requirements.

Fixes: 2249cbb53ead ("crypto: sha-mb - SHA1 multibuffer submit and flush routines for AVX2")
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/crypto/sha-mb/sha1_mb_mgr_flush_avx2.S |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

--- a/arch/x86/crypto/sha-mb/sha1_mb_mgr_flush_avx2.S
+++ b/arch/x86/crypto/sha-mb/sha1_mb_mgr_flush_avx2.S
@@ -174,8 +174,8 @@ LABEL skip_ %I
 .endr
 
 	# Find min length
-	vmovdqa _lens+0*16(state), %xmm0
-	vmovdqa _lens+1*16(state), %xmm1
+	vmovdqu _lens+0*16(state), %xmm0
+	vmovdqu _lens+1*16(state), %xmm1
 
 	vpminud %xmm1, %xmm0, %xmm2     # xmm2 has {D,C,B,A}
 	vpalignr $8, %xmm2, %xmm3, %xmm3   # xmm3 has {x,x,D,C}
@@ -195,8 +195,8 @@ LABEL skip_ %I
 	vpsubd  %xmm2, %xmm0, %xmm0
 	vpsubd  %xmm2, %xmm1, %xmm1
 
-	vmovdqa %xmm0, _lens+0*16(state)
-	vmovdqa %xmm1, _lens+1*16(state)
+	vmovdqu %xmm0, _lens+0*16(state)
+	vmovdqu %xmm1, _lens+1*16(state)
 
 	# "state" and "args" are the same address, arg1
 	# len is arg2
@@ -260,8 +260,8 @@ ENTRY(sha1_mb_mgr_get_comp_job_avx2)
 	jc      .return_null
 
 	# Find min length
-	vmovdqa _lens(state), %xmm0
-	vmovdqa _lens+1*16(state), %xmm1
+	vmovdqu _lens(state), %xmm0
+	vmovdqu _lens+1*16(state), %xmm1
 
 	vpminud %xmm1, %xmm0, %xmm2        # xmm2 has {D,C,B,A}
 	vpalignr $8, %xmm2, %xmm3, %xmm3   # xmm3 has {x,x,D,C}