Date: Tue, 4 Nov 2025 01:11:34 GMT From: Lexi Winter <ivy@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 0899f7a3b791 - main - ifconfig: Fix invalid free() in ifbridge Message-ID: <202511040111.5A41BY8N093389@gitrepo.freebsd.org>
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The branch main has been updated by ivy: URL: https://cgit.FreeBSD.org/src/commit/?id=0899f7a3b791ed4878e7cb3859636ec980c76832 commit 0899f7a3b791ed4878e7cb3859636ec980c76832 Author: Lexi Winter <ivy@FreeBSD.org> AuthorDate: 2025-11-04 00:53:25 +0000 Commit: Lexi Winter <ivy@FreeBSD.org> CommitDate: 2025-11-04 00:53:25 +0000 ifconfig: Fix invalid free() in ifbridge parse_vlans() does 's = strdup(str)', then calls strsep(&s, ...), then attempts to free(s) at the end of the function. For the success case, this is fine (s is NULL, so it's a trivial memory leak), but in the error case, we will attempt to free an invalid pointer. Fix this by storing the original return value from strdup() and freeing that instead. MFC after: 3 seconds Reported by: David Gwynne <dlg@openbsd.org> Reviewed by: zlei, kevans Sponsored by: https://www.patreon.com/bsdivy Differential Revision: https://reviews.freebsd.org/D53545 --- sbin/ifconfig/ifbridge.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/sbin/ifconfig/ifbridge.c b/sbin/ifconfig/ifbridge.c index eff443447c13..8bcf4a638adf 100644 --- a/sbin/ifconfig/ifbridge.c +++ b/sbin/ifconfig/ifbridge.c @@ -811,7 +811,7 @@ unsetbridge_private(if_ctx *ctx, const char *val, int dummy __unused) static int parse_vlans(ifbvlan_set_t *set, const char *str) { - char *s, *token; + char *s, *free_s, *token; /* "none" means the empty vlan set */ if (strcmp(str, "none") == 0) { @@ -829,6 +829,8 @@ parse_vlans(ifbvlan_set_t *set, const char *str) if ((s = strdup(str)) == NULL) return (-1); + /* Keep the original value of s, since strsep() will modify it */ + free_s = s; while ((token = strsep(&s, ",")) != NULL) { unsigned long first, last; @@ -856,11 +858,11 @@ parse_vlans(ifbvlan_set_t *set, const char *str) BRVLAN_SET(set, vlan); } - free(s); + free(free_s); return (0); err: - free(s); + free(free_s); return (-1); }help
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