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authorArd Biesheuvel <ardb@kernel.org>2020-10-27 00:00:27 +0100
committerHerbert Xu <herbert@gondor.apana.org.au>2020-11-06 04:29:11 +0100
commit519a0d7e495a6d3ce62594e485aea2a3a4a2ca0a (patch)
treed386150e9c60b6cee7b6f506cae01da5e38207c4
parentcrypto: af_alg - avoid undefined behavior accessing salg_name (diff)
downloadlinux-519a0d7e495a6d3ce62594e485aea2a3a4a2ca0a.tar.xz
linux-519a0d7e495a6d3ce62594e485aea2a3a4a2ca0a.zip
crypto: arm64/poly1305-neon - reorder PAC authentication with SP update
PAC pointer authentication signs the return address against the value of the stack pointer, to prevent stack overrun exploits from corrupting the control flow. However, this requires that the AUTIASP is issued with SP holding the same value as it held when the PAC value was generated. The Poly1305 NEON code got this wrong, resulting in crashes on PAC capable hardware. Fixes: f569ca164751 ("crypto: arm64/poly1305 - incorporate OpenSSL/CRYPTOGAMS ...") Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
-rw-r--r--arch/arm64/crypto/poly1305-armv8.pl2
-rw-r--r--arch/arm64/crypto/poly1305-core.S_shipped2
2 files changed, 2 insertions, 2 deletions
diff --git a/arch/arm64/crypto/poly1305-armv8.pl b/arch/arm64/crypto/poly1305-armv8.pl
index 6e5576d19af8..cbc980fb02e3 100644
--- a/arch/arm64/crypto/poly1305-armv8.pl
+++ b/arch/arm64/crypto/poly1305-armv8.pl
@@ -840,7 +840,6 @@ poly1305_blocks_neon:
ldp d14,d15,[sp,#64]
addp $ACC2,$ACC2,$ACC2
ldr x30,[sp,#8]
- .inst 0xd50323bf // autiasp
////////////////////////////////////////////////////////////////
// lazy reduction, but without narrowing
@@ -882,6 +881,7 @@ poly1305_blocks_neon:
str x4,[$ctx,#8] // set is_base2_26
ldr x29,[sp],#80
+ .inst 0xd50323bf // autiasp
ret
.size poly1305_blocks_neon,.-poly1305_blocks_neon
diff --git a/arch/arm64/crypto/poly1305-core.S_shipped b/arch/arm64/crypto/poly1305-core.S_shipped
index 8d1c4e420ccd..fb2822abf63a 100644
--- a/arch/arm64/crypto/poly1305-core.S_shipped
+++ b/arch/arm64/crypto/poly1305-core.S_shipped
@@ -779,7 +779,6 @@ poly1305_blocks_neon:
ldp d14,d15,[sp,#64]
addp v21.2d,v21.2d,v21.2d
ldr x30,[sp,#8]
- .inst 0xd50323bf // autiasp
////////////////////////////////////////////////////////////////
// lazy reduction, but without narrowing
@@ -821,6 +820,7 @@ poly1305_blocks_neon:
str x4,[x0,#8] // set is_base2_26
ldr x29,[sp],#80
+ .inst 0xd50323bf // autiasp
ret
.size poly1305_blocks_neon,.-poly1305_blocks_neon