[PATCH 4.13 06/33] crypto: x86/sha256-mb - fix panic due to unaligned access

[Greg Kroah-Hartman]

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

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

From: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>

commit 5dfeaac15f2b1abb5a53c9146041c7235eb9aa04 upstream.

struct sha256_ctx_mgr allocated in sha256_mb_mod_init() via kzalloc()
and later passed in sha256_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
sha256_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: a377c6b1876e ("crypto: sha256-mb - submit/flush routines for AVX2")
Reported-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Acked-by: Tim Chen
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 |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

--- a/arch/x86/crypto/sha256-mb/sha256_mb_mgr_flush_avx2.S
+++ b/arch/x86/crypto/sha256-mb/sha256_mb_mgr_flush_avx2.S
@@ -155,8 +155,8 @@ 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}
@@ -176,8 +176,8 @@ 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
@@ -234,8 +234,8 @@ ENTRY(sha256_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}