[PATCH net 4/9] sctp: sysctl: cookie_hmac_alg: avoid using current->nsproxy

Matthieu Baerts (NGI0)
2025-01-08T15:35:27Z

The 'net' structure can be obtained from the table->data using
container_of().

Note that table->data could also be used directly, as this is the only
member needed from the 'net' structure, but that would increase the size
of this fix, to use '*data' everywhere 'net->sctp.sctp_hmac_alg' is
used.

Fixes: 3c68198e7511 ("sctp: Make hmac algorithm selection for cookie generation dynamic")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/67769ecb.050a0220.3a8527.003f.GAE@google.com [1]
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
net/sctp/sysctl.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c
index e5a5af343c4c98de1afb27359c104f5030583ac4..9848d19630a4f760238a3a2abd3ec823f012d34a 100644
--- a/net/sctp/sysctl.c
+++ b/net/sctp/sysctl.c
@@ -387,7 +387,8 @@ static struct ctl_table sctp_net_table[] = {
static int proc_sctp_do_hmac_alg(const struct ctl_table *ctl, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
- struct net *net = current->nsproxy->net_ns;
+ struct net *net = container_of(ctl->data, struct net,
+ sctp.sctp_hmac_alg);
struct ctl_table tbl;
bool changed = false;
char *none = "none";

--
2.47.1