5.4-stable review patch. If anyone has any objections, please let me know.
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From: Eric Biggers ebiggers@kernel.org
commit dd91c79e4f58fbe2898dac84858033700e0e99fb upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/sctp/sm_make_chunk.c | 3 ++- net/sctp/sm_statefuns.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-)
--- 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> @@ -1758,7 +1759,7 @@ struct sctp_association *sctp_unpack_coo } }
- if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { + if (crypto_memneq(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { *error = -SCTP_IERROR_BAD_SIG; goto fail; } --- 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> @@ -4303,7 +4304,7 @@ static enum sctp_ierror sctp_sf_authenti 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; }