diff options
| author | Matthieu Baerts (NGI0) <matttbe@kernel.org> | 2025-01-08 16:34:31 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-01-09 08:53:34 -0800 |
| commit | 92cf7a51bdae24a32c592adcdd59a773ae149289 (patch) | |
| tree | b479ef8febb691eb1f699d15b25488cd1dda3d7b /net | |
| parent | d38e26e36206ae3d544d496513212ae931d1da0a (diff) | |
mptcp: sysctl: blackhole timeout: avoid using current->nsproxy
As mentioned in the previous commit, 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 'pernet' structure can be obtained from the table->data using
container_of().
Fixes: 27069e7cb3d1 ("mptcp: disable active MPTCP in case of blackhole")
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>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250108-net-sysctl-current-nsproxy-v1-3-5df34b2083e8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/mptcp/ctrl.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/net/mptcp/ctrl.c b/net/mptcp/ctrl.c index 81c30aa02196..b0dd008e2114 100644 --- a/net/mptcp/ctrl.c +++ b/net/mptcp/ctrl.c @@ -160,7 +160,9 @@ static int proc_blackhole_detect_timeout(const struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos) { - struct mptcp_pernet *pernet = mptcp_get_pernet(current->nsproxy->net_ns); + struct mptcp_pernet *pernet = container_of(table->data, + struct mptcp_pernet, + blackhole_timeout); int ret; ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); |