diff options
| author | Damien Miller <djm@cvs.openbsd.org> | 2023-02-02 12:10:06 +0000 |
|---|---|---|
| committer | Damien Miller <djm@cvs.openbsd.org> | 2023-02-02 12:10:06 +0000 |
| commit | 01120446c539b8891c0098eba1b0bc1b43b2ad63 (patch) | |
| tree | e6a7fc9839b4b1cb692863b77d3ccc7e3afea412 | |
| parent | 177df8fa64be50760eb0ae5329455e3c29e3db13 (diff) | |
fix double-free caused by compat_kex_proposal(); bz3522
by dtucker@, ok me
| -rw-r--r-- | usr.bin/ssh/compat.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/usr.bin/ssh/compat.c b/usr.bin/ssh/compat.c index babd9411f00..38c7aaa6219 100644 --- a/usr.bin/ssh/compat.c +++ b/usr.bin/ssh/compat.c @@ -1,4 +1,4 @@ -/* $OpenBSD: compat.c,v 1.120 2022/07/01 03:35:45 dtucker Exp $ */ +/* $OpenBSD: compat.c,v 1.121 2023/02/02 12:10:05 djm Exp $ */ /* * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved. * @@ -188,26 +188,26 @@ compat_pkalg_proposal(struct ssh *ssh, char *pkalg_prop) char * compat_kex_proposal(struct ssh *ssh, char *p) { - char *cp = NULL; + char *cp = NULL, *cp2 = NULL; if ((ssh->compat & (SSH_BUG_CURVE25519PAD|SSH_OLD_DHGEX)) == 0) return xstrdup(p); debug2_f("original KEX proposal: %s", p); if ((ssh->compat & SSH_BUG_CURVE25519PAD) != 0) - if ((p = match_filter_denylist(p, + if ((cp = match_filter_denylist(p, "curve25519-sha256@libssh.org")) == NULL) fatal("match_filter_denylist failed"); if ((ssh->compat & SSH_OLD_DHGEX) != 0) { - cp = p; - if ((p = match_filter_denylist(p, + if ((cp2 = match_filter_denylist(cp ? cp : p, "diffie-hellman-group-exchange-sha256," "diffie-hellman-group-exchange-sha1")) == NULL) fatal("match_filter_denylist failed"); free(cp); + cp = cp2; } - debug2_f("compat KEX proposal: %s", p); - if (*p == '\0') + if (cp == NULL || *cp == '\0') fatal("No supported key exchange algorithms found"); - return p; + debug2_f("compat KEX proposal: %s", cp); + return cp; } |