diff options
| author | Christian Brauner <brauner@kernel.org> | 2025-11-11 22:29:44 +0100 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2025-11-14 13:10:38 +0100 |
| commit | cefd55bd2159f427228d44864747243946296739 (patch) | |
| tree | cb56f7535d9a234d63501e9abb0079f0ff00edaf /kernel | |
| parent | 18b5c400482f3f42875ad3b64961bf479ea4dfaa (diff) | |
nsproxy: fix free_nsproxy() and simplify create_new_namespaces()
Make it possible to handle NULL being passed to the reference count
helpers instead of forcing the caller to handle this. Afterwards we can
nicely allow a cleanup guard to handle nsproxy freeing.
Active reference count handling is not done in nsproxy_free() but rather
in free_nsproxy() as nsproxy_free() is also called from setns() failure
paths where a new nsproxy has been prepared but has not been marked as
active via switch_task_namespaces().
Link: https://lore.kernel.org/690bfb9e.050a0220.2e3c35.0013.GAE@google.com
Link: https://patch.msgid.link/20251111-sakralbau-guthaben-7dcc277d337f@brauner
Fixes: 3c9820d5c64a ("ns: add active reference count")
Reported-by: syzbot+0b2e79f91ff6579bfa5b@syzkaller.appspotmail.com
Reported-by: syzbot+0a8655a80e189278487e@syzkaller.appspotmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/nsproxy.c | 36 |
1 files changed, 20 insertions, 16 deletions
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index 94c2cfe0afa1..259c4b4f1eeb 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -60,6 +60,25 @@ static inline struct nsproxy *create_nsproxy(void) return nsproxy; } +static inline void nsproxy_free(struct nsproxy *ns) +{ + put_mnt_ns(ns->mnt_ns); + put_uts_ns(ns->uts_ns); + put_ipc_ns(ns->ipc_ns); + put_pid_ns(ns->pid_ns_for_children); + put_time_ns(ns->time_ns); + put_time_ns(ns->time_ns_for_children); + put_cgroup_ns(ns->cgroup_ns); + put_net(ns->net_ns); + kmem_cache_free(nsproxy_cachep, ns); +} + +void deactivate_nsproxy(struct nsproxy *ns) +{ + nsproxy_ns_active_put(ns); + nsproxy_free(ns); +} + /* * Create new nsproxy and all of its the associated namespaces. * Return the newly created nsproxy. Do not attach this to the task, @@ -185,21 +204,6 @@ int copy_namespaces(u64 flags, struct task_struct *tsk) return 0; } -void free_nsproxy(struct nsproxy *ns) -{ - nsproxy_ns_active_put(ns); - - put_mnt_ns(ns->mnt_ns); - put_uts_ns(ns->uts_ns); - put_ipc_ns(ns->ipc_ns); - put_pid_ns(ns->pid_ns_for_children); - put_time_ns(ns->time_ns); - put_time_ns(ns->time_ns_for_children); - put_cgroup_ns(ns->cgroup_ns); - put_net(ns->net_ns); - kmem_cache_free(nsproxy_cachep, ns); -} - /* * Called from unshare. Unshare all the namespaces part of nsproxy. * On success, returns the new nsproxy. @@ -338,7 +342,7 @@ static void put_nsset(struct nsset *nsset) if (nsset->fs && (flags & CLONE_NEWNS) && (flags & ~CLONE_NEWNS)) free_fs_struct(nsset->fs); if (nsset->nsproxy) - free_nsproxy(nsset->nsproxy); + nsproxy_free(nsset->nsproxy); } static int prepare_nsset(unsigned flags, struct nsset *nsset) |