[PATCH 4.13 05/33] crypto: x86/sha1-mb - fix panic due to unaligned access

From: Greg Kroah-Hartman
Date: Mon Nov 13 2017 - 08:04:44 EST


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

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

From: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/x86/crypto/sha1-mb/sha1_mb_mgr_flush_avx2.S | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

--- a/arch/x86/crypto/sha1-mb/sha1_mb_mgr_flush_avx2.S
+++ b/arch/x86/crypto/sha1-mb/sha1_mb_mgr_flush_avx2.S
@@ -157,8 +157,8 @@ 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}
@@ -178,8 +178,8 @@ 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
@@ -235,8 +235,8 @@ 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}