Messages in this thread | | | Subject | Re: [PATCH] crypto: ecc: handle unaligned input buffer in ecc_swap_digits | From | Stefan Berger <> | Date | Wed, 21 Jul 2021 08:10:20 -0400 |
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On 7/21/21 4:39 AM, Mian Yousaf Kaukab wrote: > 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: 4e6602916bc6 ("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>
> --- > crypto/ecc.h | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/crypto/ecc.h b/crypto/ecc.h > index a006132646a4..1350e8eb6ac2 100644 > --- a/crypto/ecc.h > +++ b/crypto/ecc.h > @@ -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]); > } > > /**
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