[PATCH 1/2] x86/crypto/sha256-mb: fix panic due to unaligned access

From: Andrey Ryabinin
Date: Mon Oct 16 2017 - 11:48:48 EST


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>
Cc: <stable@xxxxxxxxxxxxxxx>
---
arch/x86/crypto/sha256-mb/sha256_mb_mgr_flush_avx2.S | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/crypto/sha256-mb/sha256_mb_mgr_flush_avx2.S b/arch/x86/crypto/sha256-mb/sha256_mb_mgr_flush_avx2.S
index 8fe6338bcc84..16c4ccb1f154 100644
--- 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}
--
2.13.6