The upgrade of the cookie authentication algorithm to HMAC-SHA256 kept some backwards compatibility for the net.sctp.cookie_hmac_alg sysctl by still accepting the values 'md5' and 'sha1'. Those algorithms are no longer actually used, but rather those values were just treated as requests to enable cookie authentication. As requested at https://lore.kernel.org/netdev/CADvbK_fmCRARc8VznH8cQa-QKaCOQZ6yFbF=1-VDK=zRqv_cXw@xxxxxxxxxxxxxx/ and https://lore.kernel.org/netdev/20250818084345.708ac796@xxxxxxxxxx/ , go further and start rejecting 'md5' and 'sha1' completely. Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx> --- Documentation/networking/ip-sysctl.rst | 3 --- net/sctp/sysctl.c | 4 +--- 2 files changed, 1 insertion(+), 6 deletions(-) diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst index 3d6782683eee7..43badb338d22b 100644 --- a/Documentation/networking/ip-sysctl.rst +++ b/Documentation/networking/ip-sysctl.rst @@ -3509,13 +3509,10 @@ cookie_hmac_alg - STRING Valid values are: * sha256 * none - md5 and sha1 are also accepted for backwards compatibility, but cause - sha256 to be selected. - Default: sha256 rcvbuf_policy - INTEGER Determines if the receive buffer is attributed to the socket or to association. SCTP supports the capability to create multiple diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c index 19acc57c3ed97..15e7db9a3ab2e 100644 --- a/net/sctp/sysctl.c +++ b/net/sctp/sysctl.c @@ -399,13 +399,11 @@ static int proc_sctp_do_hmac_alg(const struct ctl_table *ctl, int write, tbl.data = tmp; tbl.maxlen = sizeof(tmp) - 1; ret = proc_dostring(&tbl, 1, buffer, lenp, ppos); if (ret) return ret; - if (!strcmp(tmp, "sha256") || - /* for backwards compatibility */ - !strcmp(tmp, "md5") || !strcmp(tmp, "sha1")) { + if (!strcmp(tmp, "sha256")) { net->sctp.cookie_auth_enable = 1; return 0; } if (!strcmp(tmp, "none")) { net->sctp.cookie_auth_enable = 0; -- 2.50.1
