From: Jann Horn <ja...@google.com>

[ Upstream commit ca3fde5214e1d24f78269b337d3f22afd6bf445e ]

begin_current_label_crit_section() must run in sleepable context because
when label_is_stale() is true, aa_replace_current_label() runs, which uses
prepare_creds(), which can sleep.

Until now, the ptraceme access check (which runs with tasklist_lock held)
violated this rule.

Fixes: b2d09ae449ced ("apparmor: move ptrace checks to using labels")
Reported-by: Cyrill Gorcunov <gorcu...@gmail.com>
Reported-by: kernel test robot <rong.a.c...@intel.com>
Signed-off-by: Jann Horn <ja...@google.com>
Signed-off-by: John Johansen <john.johan...@canonical.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 security/apparmor/lsm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 4f08023101f3c..1c6b389ad8f94 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -123,11 +123,11 @@ static int apparmor_ptrace_traceme(struct task_struct 
*parent)
        struct aa_label *tracer, *tracee;
        int error;
 
-       tracee = begin_current_label_crit_section();
+       tracee = __begin_current_label_crit_section();
        tracer = aa_get_task_label(parent);
        error = aa_may_ptrace(tracer, tracee, AA_PTRACE_TRACE);
        aa_put_label(tracer);
-       end_current_label_crit_section(tracee);
+       __end_current_label_crit_section(tracee);
 
        return error;
 }
-- 
2.25.1

Reply via email to