The code assumes that everything that comes after nlmsgerr are nlattrs.
When calculating their size, it does not account for the initial
nlmsghdr. This may lead to accessing uninitialized memory.
Signed-off-by: Ilya Leoshkevich <iii@xxxxxxxxxxxxx>
---
tools/lib/bpf/nlattr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/lib/bpf/nlattr.c b/tools/lib/bpf/nlattr.c
index 3900d052ed19..975e265eab3b 100644
--- a/tools/lib/bpf/nlattr.c
+++ b/tools/lib/bpf/nlattr.c
@@ -178,7 +178,7 @@ int libbpf_nla_dump_errormsg(struct nlmsghdr *nlh)
hlen += nlmsg_len(&err->msg);
attr = (struct nlattr *) ((void *) err + hlen);
- alen = nlh->nlmsg_len - hlen;
+ alen = (void *)nlh + nlh->nlmsg_len - (void *)attr;
if (libbpf_nla_parse(tb, NLMSGERR_ATTR_MAX, attr, alen,
extack_policy) != 0) {
--
2.39.1
