Patch "crypto: p10-aes-gcm - Avoid -Wstringop-overflow warnings" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    crypto: p10-aes-gcm - Avoid -Wstringop-overflow warnings

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     crypto-p10-aes-gcm-avoid-wstringop-overflow-warnings.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 7fd2af17097ef4c2ae494811e9771c93cb98af6d
Author: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
Date:   Tue Nov 21 12:52:44 2023 -0600

    crypto: p10-aes-gcm - Avoid -Wstringop-overflow warnings
    
    [ Upstream commit aaa03fdb56c781db4a4831dd5d6ec8817918c726 ]
    
    The compiler doesn't know that `32` is an offset into the Hash table:
    
     56 struct Hash_ctx {
     57         u8 H[16];       /* subkey */
     58         u8 Htable[256]; /* Xi, Hash table(offset 32) */
     59 };
    
    So, it legitimately complains about a potential out-of-bounds issue
    if `256 bytes` are accessed in `htable` (this implies going
    `32 bytes` beyond the boundaries of `Htable`):
    
    arch/powerpc/crypto/aes-gcm-p10-glue.c: In function 'gcmp10_init':
    arch/powerpc/crypto/aes-gcm-p10-glue.c:120:9: error: 'gcm_init_htable' accessing 256 bytes in a region of size 224 [-Werror=stringop-overflow=]
      120 |         gcm_init_htable(hash->Htable+32, hash->H);
          |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    arch/powerpc/crypto/aes-gcm-p10-glue.c:120:9: note: referencing argument 1 of type 'unsigned char[256]'
    arch/powerpc/crypto/aes-gcm-p10-glue.c:120:9: note: referencing argument 2 of type 'unsigned char[16]'
    arch/powerpc/crypto/aes-gcm-p10-glue.c:40:17: note: in a call to function 'gcm_init_htable'
       40 | asmlinkage void gcm_init_htable(unsigned char htable[256], unsigned char Xi[16]);
          |                 ^~~~~~~~~~~~~~~
    
    Address this by avoiding specifying the size of `htable` in the function
    prototype; and just for consistency, do the same for parameter `Xi`.
    
    Reported-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
    Closes: https://lore.kernel.org/linux-next/20231121131903.68a37932@xxxxxxxxxxxxxxxx/
    Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
    Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/arch/powerpc/crypto/aes-gcm-p10-glue.c b/arch/powerpc/crypto/aes-gcm-p10-glue.c
index 4b6e899895e7..f62ee54076c0 100644
--- a/arch/powerpc/crypto/aes-gcm-p10-glue.c
+++ b/arch/powerpc/crypto/aes-gcm-p10-glue.c
@@ -37,7 +37,7 @@ asmlinkage void aes_p10_gcm_encrypt(u8 *in, u8 *out, size_t len,
 				    void *rkey, u8 *iv, void *Xi);
 asmlinkage void aes_p10_gcm_decrypt(u8 *in, u8 *out, size_t len,
 				    void *rkey, u8 *iv, void *Xi);
-asmlinkage void gcm_init_htable(unsigned char htable[256], unsigned char Xi[16]);
+asmlinkage void gcm_init_htable(unsigned char htable[], unsigned char Xi[]);
 asmlinkage void gcm_ghash_p10(unsigned char *Xi, unsigned char *Htable,
 		unsigned char *aad, unsigned int alen);