| Message ID | 1424935325-14437-1-git-send-email-ard.biesheuvel@linaro.org |
|---|---|
| State | Accepted |
| Commit | 001eabfd54c0cbf9d7d16264ddc8cc0bee67e3ed |
| Headers | show |
On 28 February 2015 at 22:30, Milan Broz <gmazyland@gmail.com> wrote: > On 02/26/2015 08:22 AM, Ard Biesheuvel wrote: >> This updates the bit sliced AES module to the latest version in the >> upstream OpenSSL repository (e620e5ae37bc). This is needed to fix a >> bug in the XTS decryption path, where data chunked in a certain way >> could trigger the ciphertext stealing code, which is not supposed to >> be active in the kernel build (The kernel implementation of XTS only >> supports round multiples of the AES block size of 16 bytes, whereas >> the conformant OpenSSL implementation of XTS supports inputs of >> arbitrary size by applying ciphertext stealing). This is fixed in >> the upstream version by adding the missing #ifndef XTS_CHAIN_TWEAK >> around the offending instructions. >> >> The upstream code also contains the change applied by Russell to >> build the code unconditionally, i.e., even if __LINUX_ARM_ARCH__ < 7, >> but implemented slightly differently. >> >> Fixes: e4e7f10bfc40 ("ARM: add support for bit sliced AES using NEON instructions") >> Reported-by: Adrian Kotelba <adrian.kotelba@gmail.com> >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> >> --- >> >> This was found using the tcrypt test code, to which I recently added additional >> chunking modes. However, XTS typically operates on pages or at least on sectors, >> so this bug is unlikely to affect anyone in real life. >> >> Still, please add cc stable when applying, > > Please apply it for stable. > > For me, this patch fixed bug reported here > http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/7966 > http://www.mail-archive.com/linux-crypto@vger.kernel.org/msg13102.html > > Cryptsetup uses AF_ALG userspace crypto SKCIPHER interface and on > Raspberry Pi2 with Neon AES implementation it fails to unlock LUKS device > (if XTS and aes-arm-bs module is used). > > After applying this patch it works as expected. > > I did not have time to check it more in detail (we are always encrypting > the whole sector so this should not happen... but apparently it does.) > > Tested-by: Milan Broz <gmazyland@gmail.com> > OK, thanks for pointing that out, and for confirming that this fixes the issue. Actually, I did not consider the userspace use case, but it is not surprising that the data ends up being pushed into the crypto layer in odd size chunks. @Herbert: are you ok to take this as a bug fix for stable? Thanks, Ard. >> arch/arm/crypto/aesbs-core.S_shipped | 12 ++++++++---- >> arch/arm/crypto/bsaes-armv7.pl | 12 ++++++++---- >> 2 files changed, 16 insertions(+), 8 deletions(-) >> >> diff --git a/arch/arm/crypto/aesbs-core.S_shipped b/arch/arm/crypto/aesbs-core.S_shipped >> index 71e5fc7cfb18..1d1800f71c5b 100644 >> --- a/arch/arm/crypto/aesbs-core.S_shipped >> +++ b/arch/arm/crypto/aesbs-core.S_shipped >> @@ -58,14 +58,18 @@ >> # define VFP_ABI_FRAME 0 >> # define BSAES_ASM_EXTENDED_KEY >> # define XTS_CHAIN_TWEAK >> -# define __ARM_ARCH__ 7 >> +# define __ARM_ARCH__ __LINUX_ARM_ARCH__ >> +# define __ARM_MAX_ARCH__ 7 >> #endif >> >> #ifdef __thumb__ >> # define adrl adr >> #endif >> >> -#if __ARM_ARCH__>=7 >> +#if __ARM_MAX_ARCH__>=7 >> +.arch armv7-a >> +.fpu neon >> + >> .text >> .syntax unified @ ARMv7-capable assembler is expected to handle this >> #ifdef __thumb2__ >> @@ -74,8 +78,6 @@ >> .code 32 >> #endif >> >> -.fpu neon >> - >> .type _bsaes_decrypt8,%function >> .align 4 >> _bsaes_decrypt8: >> @@ -2095,9 +2097,11 @@ bsaes_xts_decrypt: >> vld1.8 {q8}, [r0] @ initial tweak >> adr r2, .Lxts_magic >> >> +#ifndef XTS_CHAIN_TWEAK >> tst r9, #0xf @ if not multiple of 16 >> it ne @ Thumb2 thing, sanity check in ARM >> subne r9, #0x10 @ subtract another 16 bytes >> +#endif >> subs r9, #0x80 >> >> blo .Lxts_dec_short >> diff --git a/arch/arm/crypto/bsaes-armv7.pl b/arch/arm/crypto/bsaes-armv7.pl >> index be068db960ee..a4d3856e7d24 100644 >> --- a/arch/arm/crypto/bsaes-armv7.pl >> +++ b/arch/arm/crypto/bsaes-armv7.pl >> @@ -701,14 +701,18 @@ $code.=<<___; >> # define VFP_ABI_FRAME 0 >> # define BSAES_ASM_EXTENDED_KEY >> # define XTS_CHAIN_TWEAK >> -# define __ARM_ARCH__ 7 >> +# define __ARM_ARCH__ __LINUX_ARM_ARCH__ >> +# define __ARM_MAX_ARCH__ 7 >> #endif >> >> #ifdef __thumb__ >> # define adrl adr >> #endif >> >> -#if __ARM_ARCH__>=7 >> +#if __ARM_MAX_ARCH__>=7 >> +.arch armv7-a >> +.fpu neon >> + >> .text >> .syntax unified @ ARMv7-capable assembler is expected to handle this >> #ifdef __thumb2__ >> @@ -717,8 +721,6 @@ $code.=<<___; >> .code 32 >> #endif >> >> -.fpu neon >> - >> .type _bsaes_decrypt8,%function >> .align 4 >> _bsaes_decrypt8: >> @@ -2076,9 +2078,11 @@ bsaes_xts_decrypt: >> vld1.8 {@XMM[8]}, [r0] @ initial tweak >> adr $magic, .Lxts_magic >> >> +#ifndef XTS_CHAIN_TWEAK >> tst $len, #0xf @ if not multiple of 16 >> it ne @ Thumb2 thing, sanity check in ARM >> subne $len, #0x10 @ subtract another 16 bytes >> +#endif >> subs $len, #0x80 >> >> blo .Lxts_dec_short >> > -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/arm/crypto/aesbs-core.S_shipped b/arch/arm/crypto/aesbs-core.S_shipped index 71e5fc7cfb18..1d1800f71c5b 100644 --- a/arch/arm/crypto/aesbs-core.S_shipped +++ b/arch/arm/crypto/aesbs-core.S_shipped @@ -58,14 +58,18 @@ # define VFP_ABI_FRAME 0 # define BSAES_ASM_EXTENDED_KEY # define XTS_CHAIN_TWEAK -# define __ARM_ARCH__ 7 +# define __ARM_ARCH__ __LINUX_ARM_ARCH__ +# define __ARM_MAX_ARCH__ 7 #endif #ifdef __thumb__ # define adrl adr #endif -#if __ARM_ARCH__>=7 +#if __ARM_MAX_ARCH__>=7 +.arch armv7-a +.fpu neon + .text .syntax unified @ ARMv7-capable assembler is expected to handle this #ifdef __thumb2__ @@ -74,8 +78,6 @@ .code 32 #endif -.fpu neon - .type _bsaes_decrypt8,%function .align 4 _bsaes_decrypt8: @@ -2095,9 +2097,11 @@ bsaes_xts_decrypt: vld1.8 {q8}, [r0] @ initial tweak adr r2, .Lxts_magic +#ifndef XTS_CHAIN_TWEAK tst r9, #0xf @ if not multiple of 16 it ne @ Thumb2 thing, sanity check in ARM subne r9, #0x10 @ subtract another 16 bytes +#endif subs r9, #0x80 blo .Lxts_dec_short diff --git a/arch/arm/crypto/bsaes-armv7.pl b/arch/arm/crypto/bsaes-armv7.pl index be068db960ee..a4d3856e7d24 100644 --- a/arch/arm/crypto/bsaes-armv7.pl +++ b/arch/arm/crypto/bsaes-armv7.pl @@ -701,14 +701,18 @@ $code.=<<___; # define VFP_ABI_FRAME 0 # define BSAES_ASM_EXTENDED_KEY # define XTS_CHAIN_TWEAK -# define __ARM_ARCH__ 7 +# define __ARM_ARCH__ __LINUX_ARM_ARCH__ +# define __ARM_MAX_ARCH__ 7 #endif #ifdef __thumb__ # define adrl adr #endif -#if __ARM_ARCH__>=7 +#if __ARM_MAX_ARCH__>=7 +.arch armv7-a +.fpu neon + .text .syntax unified @ ARMv7-capable assembler is expected to handle this #ifdef __thumb2__ @@ -717,8 +721,6 @@ $code.=<<___; .code 32 #endif -.fpu neon - .type _bsaes_decrypt8,%function .align 4 _bsaes_decrypt8: @@ -2076,9 +2078,11 @@ bsaes_xts_decrypt: vld1.8 {@XMM[8]}, [r0] @ initial tweak adr $magic, .Lxts_magic +#ifndef XTS_CHAIN_TWEAK tst $len, #0xf @ if not multiple of 16 it ne @ Thumb2 thing, sanity check in ARM subne $len, #0x10 @ subtract another 16 bytes +#endif subs $len, #0x80 blo .Lxts_dec_short
This updates the bit sliced AES module to the latest version in the upstream OpenSSL repository (e620e5ae37bc). This is needed to fix a bug in the XTS decryption path, where data chunked in a certain way could trigger the ciphertext stealing code, which is not supposed to be active in the kernel build (The kernel implementation of XTS only supports round multiples of the AES block size of 16 bytes, whereas the conformant OpenSSL implementation of XTS supports inputs of arbitrary size by applying ciphertext stealing). This is fixed in the upstream version by adding the missing #ifndef XTS_CHAIN_TWEAK around the offending instructions. The upstream code also contains the change applied by Russell to build the code unconditionally, i.e., even if __LINUX_ARM_ARCH__ < 7, but implemented slightly differently. Fixes: e4e7f10bfc40 ("ARM: add support for bit sliced AES using NEON instructions") Reported-by: Adrian Kotelba <adrian.kotelba@gmail.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- This was found using the tcrypt test code, to which I recently added additional chunking modes. However, XTS typically operates on pages or at least on sectors, so this bug is unlikely to affect anyone in real life. Still, please add cc stable when applying, Thanks, Ard. arch/arm/crypto/aesbs-core.S_shipped | 12 ++++++++---- arch/arm/crypto/bsaes-armv7.pl | 12 ++++++++---- 2 files changed, 16 insertions(+), 8 deletions(-)