From: John Johansen <john.johansen@canonical.com> stable inclusion from stable-v6.6.130 commit 3f8699b3ee0c04b4b9bc27b82cd89a40e81e1d2e category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/14047 CVE: CVE-2026-23405 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 306039414932c80f8420695a24d4fe10c84ccfb2 upstream. Currently the number of policy namespaces is not bounded relying on the user namespace limit. However policy namespaces aren't strictly tied to user namespaces and it is possible to create them and nest them arbitrarily deep which can be used to exhaust system resource. Hard cap policy namespaces to the same depth as user namespaces. Fixes: c88d4c7b049e8 ("AppArmor: core policy routines") Reported-by: Qualys Security Advisory <qsa@qualys.com> Reviewed-by: Ryan Lee <ryan.lee@canonical.com> Reviewed-by: Cengiz Can <cengiz.can@canonical.com> Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Cui GaoSheng <cuigaosheng1@huawei.com> --- security/apparmor/include/policy_ns.h | 2 ++ security/apparmor/policy_ns.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/security/apparmor/include/policy_ns.h b/security/apparmor/include/policy_ns.h index 33d665516fc1..dabb69bc87e0 100644 --- a/security/apparmor/include/policy_ns.h +++ b/security/apparmor/include/policy_ns.h @@ -18,6 +18,8 @@ #include "label.h" #include "policy.h" +/* Match max depth of user namespaces */ +#define MAX_NS_DEPTH 32 /* struct aa_ns_acct - accounting of profiles in namespace * @max_size: maximum space allowed for all profiles in namespace diff --git a/security/apparmor/policy_ns.c b/security/apparmor/policy_ns.c index fd5b7afbcb48..c56ef36baef4 100644 --- a/security/apparmor/policy_ns.c +++ b/security/apparmor/policy_ns.c @@ -260,6 +260,8 @@ static struct aa_ns *__aa_create_ns(struct aa_ns *parent, const char *name, AA_BUG(!name); AA_BUG(!mutex_is_locked(&parent->lock)); + if (parent->level > MAX_NS_DEPTH) + return ERR_PTR(-ENOSPC); ns = alloc_ns(parent->base.hname, name); if (!ns) return ERR_PTR(-ENOMEM); -- 2.34.1