From d2324a9317f00013facb0ba00b00440e19d2af5e Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Thu, 26 Feb 2026 14:50:10 +0100 Subject: [PATCH] nsfs: tighten permission checks for handle opening Even privileged services should not necessarily be able to see other privileged service's namespaces so they can't leak information to each other. Use may_see_all_namespaces() helper that centralizes this policy until the nstree adapts. Link: https://patch.msgid.link/20260226-work-visibility-fixes-v1-2-d2c2853313bd@kernel.org Fixes: 5222470b2fbb ("nsfs: support file handles") Reviewed-by: Jeff Layton Cc: stable@kernel.org # v6.18+ Signed-off-by: Christian Brauner --- fs/nsfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/nsfs.c b/fs/nsfs.c index be36c10c38cf..c215878d55e8 100644 --- a/fs/nsfs.c +++ b/fs/nsfs.c @@ -627,7 +627,7 @@ static struct dentry *nsfs_fh_to_dentry(struct super_block *sb, struct fid *fh, return ERR_PTR(-EOPNOTSUPP); } - if (owning_ns && !ns_capable(owning_ns, CAP_SYS_ADMIN)) { + if (owning_ns && !may_see_all_namespaces()) { ns->ops->put(ns); return ERR_PTR(-EPERM); }