| Message ID | 20250108-net-sysctl-current-nsproxy-v1-7-5df34b2083e8@kernel.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | net: sysctl: avoid using current->nsproxy | expand |
diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c index 9d29611621feaf0d2e8d7c923601ab374515563b..18fa4f44e8ec8c86f8415b1251ef8a2979c7f823 100644 --- a/net/sctp/sysctl.c +++ b/net/sctp/sysctl.c @@ -528,7 +528,7 @@ static int proc_sctp_do_auth(const struct ctl_table *ctl, int write, static int proc_sctp_do_udp_port(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.udp_port); unsigned int min = *(unsigned int *)ctl->extra1; unsigned int max = *(unsigned int *)ctl->extra2; struct ctl_table tbl;
As mentioned in a previous commit of this series, using the 'net' structure via 'current' is not recommended for different reasons: - Inconsistency: getting info from the reader's/writer's netns vs only from the opener's netns. - current->nsproxy can be NULL in some cases, resulting in an 'Oops' (null-ptr-deref), e.g. when the current task is exiting, as spotted by syzbot [1] using acct(2). The 'net' structure can be obtained from the table->data using container_of(). Note that table->data could also be used directly, but that would increase the size of this fix, while 'sctp.ctl_sock' still needs to be retrieved from 'net' structure. Fixes: 046c052b475e ("sctp: enable udp tunneling socks") 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 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)