From: Eric Biggers <ebiggers@kernel.org> mainline inclusion from mainline-v6.18-rc1 commit dd91c79e4f58fbe2898dac84858033700e0e99fb category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ID6BW6 CVE: CVE-2025-40204 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: bbd0d59809f9 ("[SCTP]: Implement the receive and verification of AUTH chunk") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org> Link: https://patch.msgid.link/20250818205426.30222-3-ebiggers@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Conflicts: net/sctp/sm_make_chunk.c net/sctp/sm_statefuns.c [conflicts due to not merge c616fb0cbae8 ("crypto: lib/utils - Move utilities into new header")] Signed-off-by: Wang Liang <wangliang74@huawei.com> --- net/sctp/sm_make_chunk.c | 3 ++- net/sctp/sm_statefuns.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index 64e0f4864b73..cf77c4693b91 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -31,6 +31,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <crypto/hash.h> +#include <crypto/algapi.h> #include <linux/types.h> #include <linux/kernel.h> #include <linux/ip.h> @@ -1751,7 +1752,7 @@ struct sctp_association *sctp_unpack_cookie( } } - if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { + if (crypto_memneq(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { *error = -SCTP_IERROR_BAD_SIG; goto fail; } diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c index 93ebd14b48ed..9f2aa475c291 100644 --- a/net/sctp/sm_statefuns.c +++ b/net/sctp/sm_statefuns.c @@ -30,6 +30,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <crypto/algapi.h> #include <linux/types.h> #include <linux/kernel.h> #include <linux/ip.h> @@ -4302,7 +4303,7 @@ static enum sctp_ierror sctp_sf_authenticate( sh_key, GFP_ATOMIC); /* Discard the packet if the digests do not match */ - if (memcmp(save_digest, digest, sig_len)) { + if (crypto_memneq(save_digest, digest, sig_len)) { kfree(save_digest); return SCTP_IERROR_BAD_SIG; } -- 2.34.1