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crypto: ecc - handle unaligned input buffer in ecc_swap_digits 

ecdsa_set_pub_key() makes an u64 pointer at 1 byte offset of the key.
This results in an unaligned u64 pointer. This pointer is passed to
ecc_swap_digits() which assumes natural alignment.

This causes a kernel crash on an armv7 platform:
[    0.409022] Unhandled fault: alignment exception (0x001) at 0xc2a0a6a9
...
[    0.416982] PC is at ecdsa_set_pub_key+0xdc/0x120
...
[    0.491492] Backtrace:
[    0.492059] [<c07c266c>] (ecdsa_set_pub_key) from [<c07c75d4>] (test_akcipher_one+0xf4/0x6c0)

Handle unaligned input buffer in ecc_swap_digits() by replacing
be64_to_cpu() to get_unaligned_be64(). Change type of in pointer to
void to reflect it doesn’t necessarily need to be aligned.

Fixes: 4e6602916b ("crypto: ecdsa - Add support for ECDSA signature verification")
Reported-by: Guillaume Gardet <guillaume.gardet@arm.com>
Suggested-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mian Yousaf Kaukab <ykaukab@suse.de>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Mian Yousaf Kaukab 2021-07-21 10:39:05 +02:00 committed by Herbert Xu
parent d5ee8e750c
commit 0469dede0e
1 changed files with 3 additions and 2 deletions
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5
crypto/ecc.h
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@ -27,6 +27,7 @@
#define _CRYPTO_ECC_H
#include <crypto/ecc_curve.h>
#include <asm/unaligned.h>
/* One digit is u64 qword. */
#define ECC_CURVE_NIST_P192_DIGITS 3
@ -46,13 +47,13 @@
* @out: Output array
* @ndigits: Number of digits to copy
*/
static inline void ecc_swap_digits(const u64 *in, u64 *out, unsigned int ndigits)
static inline void ecc_swap_digits(const void *in, u64 *out, unsigned int ndigits)
{
const __be64 *src = (__force __be64 *)in;
int i;
for (i = 0; i < ndigits; i++)
out[i] = be64_to_cpu(src[ndigits - 1 - i]);
out[i] = get_unaligned_be64(&src[ndigits - 1 - i]);
}
/**