From 2d83a7d4f58fbf6eaa9aeace49c78d91a86a3b28 Mon Sep 17 00:00:00 2001 From: Phil Sutter Date: Wed, 31 May 2023 14:09:09 +0200 Subject: set: Do not leave free'd expr_list elements in place When freeing elements, remove them also to prevent a potential UAF. Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1685 Fixes: 3469f09286cee ("src: add NFTNL_SET_EXPRESSIONS") Signed-off-by: Phil Sutter --- src/set.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/src/set.c b/src/set.c index c46f827..719e596 100644 --- a/src/set.c +++ b/src/set.c @@ -54,8 +54,10 @@ void nftnl_set_free(const struct nftnl_set *s) if (s->flags & (1 << NFTNL_SET_USERDATA)) xfree(s->user.data); - list_for_each_entry_safe(expr, next, &s->expr_list, head) + list_for_each_entry_safe(expr, next, &s->expr_list, head) { + list_del(&expr->head); nftnl_expr_free(expr); + } list_for_each_entry_safe(elem, tmp, &s->element_list, head) { list_del(&elem->head); @@ -105,8 +107,10 @@ void nftnl_set_unset(struct nftnl_set *s, uint16_t attr) break; case NFTNL_SET_EXPR: case NFTNL_SET_EXPRESSIONS: - list_for_each_entry_safe(expr, tmp, &s->expr_list, head) + list_for_each_entry_safe(expr, tmp, &s->expr_list, head) { + list_del(&expr->head); nftnl_expr_free(expr); + } break; default: return; @@ -210,8 +214,10 @@ int nftnl_set_set_data(struct nftnl_set *s, uint16_t attr, const void *data, s->user.len = data_len; break; case NFTNL_SET_EXPR: - list_for_each_entry_safe(expr, tmp, &s->expr_list, head) + list_for_each_entry_safe(expr, tmp, &s->expr_list, head) { + list_del(&expr->head); nftnl_expr_free(expr); + } expr = (void *)data; list_add(&expr->head, &s->expr_list); @@ -742,8 +748,10 @@ int nftnl_set_nlmsg_parse(const struct nlmsghdr *nlh, struct nftnl_set *s) return 0; out_set_expr: - list_for_each_entry_safe(expr, next, &s->expr_list, head) + list_for_each_entry_safe(expr, next, &s->expr_list, head) { + list_del(&expr->head); nftnl_expr_free(expr); + } return -1; } -- cgit v1.2.3