Re: [PATCH] x86/crypto/sm4: Fix frame pointer stack corruption

[Herbert Xu]

On Tue, Sep 21, 2021 at 10:40:26PM -0700, Josh Poimboeuf wrote:
> sm4_aesni_avx_crypt8() sets up the frame pointer (which includes pushing
> RBP) before doing a conditional sibling call to sm4_aesni_avx_crypt4(),
> which sets up an additional frame pointer.  Things will not go well when
> sm4_aesni_avx_crypt4() pops only the innermost single frame pointer and
> then tries to return to the outermost frame pointer.
> 
> Sibling calls need to occur with an empty stack frame.  Do the
> conditional sibling call *before* setting up the stack pointer.
> 
> This fixes the following warning:
> 
>   arch/x86/crypto/sm4-aesni-avx-asm_64.o: warning: objtool: sm4_aesni_avx_crypt8()+0x8: sibling call from callable instruction with modified stack frame
> 
> Fixes: a7ee22ee1445 ("crypto: x86/sm4 - add AES-NI/AVX/x86_64 implementation")
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Reported-by: Arnd Bergmann <arnd@xxxxxxxxxx>
> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> Reviewed-by: Tianjia Zhang <tianjia.zhang@xxxxxxxxxxxxxxxxx>
> Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> ---
>  arch/x86/crypto/sm4-aesni-avx-asm_64.S | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)

Patch applied.  Thanks.
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
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