From: Eric Biggers <ebiggers@kernel.org> mainline inclusion from mainline-v6.17-rc3 commit a458b2902115b26a25d67393b12ddd57d1216aaa category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/9027 CVE: CVE-2025-39702 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- To prevent timing attacks, MACs need to be compared in constant time. Use the appropriate helper function for this. Fixes: bf355b8d2c30 ("ipv6: sr: add core files for SR HMAC support") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org> Reviewed-by: Andrea Mayer <andrea.mayer@uniroma2.it> Link: https://patch.msgid.link/20250818202724.15713-1-ebiggers@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Conflicts: net/ipv6/seg6_hmac.c [conflicts due to not merge c616fb0cbae8 ("crypto: lib/utils - Move utilities into new header")] Signed-off-by: Wang Liang <wangliang74@huawei.com> Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com> Reviewed-by: Yue Haibing <yuehaibing@huawei.com> Reviewed-by: Yue Haibing <yuehaibing@huawei.com> --- net/ipv6/seg6_hmac.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv6/seg6_hmac.c b/net/ipv6/seg6_hmac.c index 3c38002..dd7406a 100644 --- a/net/ipv6/seg6_hmac.c +++ b/net/ipv6/seg6_hmac.c @@ -35,6 +35,7 @@ #include <net/xfrm.h> #include <crypto/hash.h> +#include <crypto/algapi.h> #include <net/seg6.h> #include <net/genetlink.h> #include <net/seg6_hmac.h> @@ -269,7 +270,7 @@ bool seg6_hmac_validate_skb(struct sk_buff *skb) if (seg6_hmac_compute(hinfo, srh, &ipv6_hdr(skb)->saddr, hmac_output)) return false; - if (memcmp(hmac_output, tlv->hmac, SEG6_HMAC_FIELD_LEN) != 0) + if (crypto_memneq(hmac_output, tlv->hmac, SEG6_HMAC_FIELD_LEN)) return false; return true; -- 2.9.5