diff options
| author |   Junaid Shahid <junaids@google.com> | 2017-12-20 17:08:38 -0800 |
|---|---|---|
| committer |   Herbert Xu <herbert@gondor.apana.org.au> | 2017-12-28 17:56:51 +1100 |
| commit | 1ecdd37e308ca149dc378cce225068cbac54e3a6 (patch) | |
| tree | aa6a2ab409ff3add306f6144ca5e7a415b3ed56f | |
| parent | crypto: aesni - Fix out-of-bounds access of the data buffer in generic-gcm-aesni (diff) | |
| download | linux-dev-1ecdd37e308ca149dc378cce225068cbac54e3a6.tar.xz linux-dev-1ecdd37e308ca149dc378cce225068cbac54e3a6.zip | |
crypto: aesni - Fix out-of-bounds access of the AAD buffer in generic-gcm-aesni
The aesni_gcm_enc/dec functions can access memory after the end of
the AAD buffer if the AAD length is not a multiple of 4 bytes.
It didn't matter with rfc4106-gcm-aesni as in that case the AAD was
always followed by the 8 byte IV, but that is no longer the case with
generic-gcm-aesni. This can potentially result in accessing a page that
is not mapped and thus causing the machine to crash. This patch fixes
that by reading the last <16 byte block of the AAD byte-by-byte and
optionally via an 8-byte load if the block was at least 8 bytes.
Fixes: 0487ccac ("crypto: aesni - make non-AVX AES-GCM work with any aadlen")
Cc: <stable@vger.kernel.org>
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| -rw-r--r-- | arch/x86/crypto/aesni-intel_asm.S | 112 |
1 files changed, 12 insertions, 100 deletions
diff --git a/arch/x86/crypto/aesni-intel_asm.S b/arch/x86/crypto/aesni-intel_asm.S index c36b850fdc81..76d8cd426a31 100644 --- a/arch/x86/crypto/aesni-intel_asm.S +++ b/arch/x86/crypto/aesni-intel_asm.S @@ -89,30 +89,6 @@ SHIFT_MASK: .octa 0x0f0e0d0c0b0a09080706050403020100 ALL_F: .octa 0xffffffffffffffffffffffffffffffff .octa 0x00000000000000000000000000000000 -.section .rodata -.align 16 -.type aad_shift_arr, @object -.size aad_shift_arr, 272 -aad_shift_arr: - .octa 0xffffffffffffffffffffffffffffffff - .octa 0xffffffffffffffffffffffffffffff0C - .octa 0xffffffffffffffffffffffffffff0D0C - .octa 0xffffffffffffffffffffffffff0E0D0C - .octa 0xffffffffffffffffffffffff0F0E0D0C - .octa 0xffffffffffffffffffffff0C0B0A0908 - .octa 0xffffffffffffffffffff0D0C0B0A0908 - .octa 0xffffffffffffffffff0E0D0C0B0A0908 - .octa 0xffffffffffffffff0F0E0D0C0B0A0908 - .octa 0xffffffffffffff0C0B0A090807060504 - .octa 0xffffffffffff0D0C0B0A090807060504 - .octa 0xffffffffff0E0D0C0B0A090807060504 - .octa 0xffffffff0F0E0D0C0B0A090807060504 - .octa 0xffffff0C0B0A09080706050403020100 - .octa 0xffff0D0C0B0A09080706050403020100 - .octa 0xff0E0D0C0B0A09080706050403020100 - .octa 0x0F0E0D0C0B0A09080706050403020100 - - .text @@ -303,62 +279,30 @@ _done_read_partial_block_\@: XMM2 XMM3 XMM4 XMMDst TMP6 TMP7 i i_seq operation MOVADQ SHUF_MASK(%rip), %xmm14 mov arg7, %r10 # %r10 = AAD - mov arg8, %r12 # %r12 = aadLen - mov %r12, %r11 + mov arg8, %r11 # %r11 = aadLen pxor %xmm\i, %xmm\i pxor \XMM2, \XMM2 cmp $16, %r11 - jl _get_AAD_rest8\num_initial_blocks\operation + jl _get_AAD_rest\num_initial_blocks\operation _get_AAD_blocks\num_initial_blocks\operation: movdqu (%r10), %xmm\i PSHUFB_XMM %xmm14, %xmm\i # byte-reflect the AAD data pxor %xmm\i, \XMM2 GHASH_MUL \XMM2, \TMP3, \TMP1, \TMP2, \TMP4, \TMP5, \XMM1 add $16, %r10 - sub $16, %r12 sub $16, %r11 cmp $16, %r11 jge _get_AAD_blocks\num_initial_blocks\operation movdqu \XMM2, %xmm\i + + /* read the last <16B of AAD */ +_get_AAD_rest\num_initial_blocks\operation: cmp $0, %r11 je _get_AAD_done\num_initial_blocks\operation - pxor %xmm\i,%xmm\i - - /* read the last <16B of AAD. since we have at least 4B of - data right after the AAD (the ICV, and maybe some CT), we can - read 4B/8B blocks safely, and then get rid of the extra stuff */ -_get_AAD_rest8\num_initial_blocks\operation: - cmp $4, %r11 - jle _get_AAD_rest4\num_initial_blocks\operation - movq (%r10), \TMP1 - add $8, %r10 - sub $8, %r11 - pslldq $8, \TMP1 - psrldq $8, %xmm\i - pxor \TMP1, %xmm\i - jmp _get_AAD_rest8\num_initial_blocks\operation -_get_AAD_rest4\num_initial_blocks\operation: - cmp $0, %r11 - jle _get_AAD_rest0\num_initial_blocks\operation - mov (%r10), %eax - movq %rax, \TMP1 - add $4, %r10 - sub $4, %r10 - pslldq $12, \TMP1 - psrldq $4, %xmm\i - pxor \TMP1, %xmm\i -_get_AAD_rest0\num_initial_blocks\operation: - /* finalize: shift out the extra bytes we read, and align - left. since pslldq can only shift by an immediate, we use - vpshufb and an array of shuffle masks */ - movq %r12, %r11 - salq $4, %r11 - movdqu aad_shift_arr(%r11), \TMP1 - PSHUFB_XMM \TMP1, %xmm\i -_get_AAD_rest_final\num_initial_blocks\operation: + READ_PARTIAL_BLOCK %r10, %r11, \TMP1, %xmm\i PSHUFB_XMM %xmm14, %xmm\i # byte-reflect the AAD data pxor \XMM2, %xmm\i GHASH_MUL %xmm\i, \TMP3, \TMP1, \TMP2, \TMP4, \TMP5, \XMM1 @@ -562,62 +506,30 @@ _initial_blocks_done\num_initial_blocks\operation: XMM2 XMM3 XMM4 XMMDst TMP6 TMP7 i i_seq operation MOVADQ SHUF_MASK(%rip), %xmm14 mov arg7, %r10 # %r10 = AAD - mov arg8, %r12 # %r12 = aadLen - mov %r12, %r11 + mov arg8, %r11 # %r11 = aadLen pxor %xmm\i, %xmm\i pxor \XMM2, \XMM2 cmp $16, %r11 - jl _get_AAD_rest8\num_initial_blocks\operation + jl _get_AAD_rest\num_initial_blocks\operation _get_AAD_blocks\num_initial_blocks\operation: movdqu (%r10), %xmm\i PSHUFB_XMM %xmm14, %xmm\i # byte-reflect the AAD data pxor %xmm\i, \XMM2 GHASH_MUL \XMM2, \TMP3, \TMP1, \TMP2, \TMP4, \TMP5, \XMM1 add $16, %r10 - sub $16, %r12 sub $16, %r11 cmp $16, %r11 jge _get_AAD_blocks\num_initial_blocks\operation movdqu \XMM2, %xmm\i + + /* read the last <16B of AAD */ +_get_AAD_rest\num_initial_blocks\operation: cmp $0, %r11 je _get_AAD_done\num_initial_blocks\operation - pxor %xmm\i,%xmm\i - - /* read the last <16B of AAD. since we have at least 4B of - data right after the AAD (the ICV, and maybe some PT), we can - read 4B/8B blocks safely, and then get rid of the extra stuff */ -_get_AAD_rest8\num_initial_blocks\operation: - cmp $4, %r11 - jle _get_AAD_rest4\num_initial_blocks\operation - movq (%r10), \TMP1 - add $8, %r10 - sub $8, %r11 - pslldq $8, \TMP1 - psrldq $8, %xmm\i - pxor \TMP1, %xmm\i - jmp _get_AAD_rest8\num_initial_blocks\operation -_get_AAD_rest4\num_initial_blocks\operation: - cmp $0, %r11 - jle _get_AAD_rest0\num_initial_blocks\operation - mov (%r10), %eax - movq %rax, \TMP1 - add $4, %r10 - sub $4, %r10 - pslldq $12, \TMP1 - psrldq $4, %xmm\i - pxor \TMP1, %xmm\i -_get_AAD_rest0\num_initial_blocks\operation: - /* finalize: shift out the extra bytes we read, and align - left. since pslldq can only shift by an immediate, we use - vpshufb and an array of shuffle masks */ - movq %r12, %r11 - salq $4, %r11 - movdqu aad_shift_arr(%r11), \TMP1 - PSHUFB_XMM \TMP1, %xmm\i -_get_AAD_rest_final\num_initial_blocks\operation: + READ_PARTIAL_BLOCK %r10, %r11, \TMP1, %xmm\i PSHUFB_XMM %xmm14, %xmm\i # byte-reflect the AAD data pxor \XMM2, %xmm\i GHASH_MUL %xmm\i, \TMP3, \TMP1, \TMP2, \TMP4, \TMP5, \XMM1 |