From: Ard Biesheuvel ardb@kernel.org
[ Upstream commit 519a0d7e495a6d3ce62594e485aea2a3a4a2ca0a ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm64/crypto/poly1305-armv8.pl | 2 +- arch/arm64/crypto/poly1305-core.S_shipped | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/crypto/poly1305-armv8.pl b/arch/arm64/crypto/poly1305-armv8.pl index 6e5576d19af8f..cbc980fb02e33 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 8d1c4e420ccdc..fb2822abf63aa 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