From 1f8266ff58840d698a1e96d2274189de1bdf7969 Mon Sep 17 00:00:00 2001 From: Jann Horn Date: Thu, 13 Sep 2018 18:12:09 +0200 Subject: apparmor: don't try to replace stale label in ptrace access check As a comment above begin_current_label_crit_section() explains, 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 ptrace access check (which runs with a task lock held) violated this rule. Also add a might_sleep() assertion to begin_current_label_crit_section(), because asserts are less likely to be ignored than comments. Fixes: b2d09ae449ced ("apparmor: move ptrace checks to using labels") Signed-off-by: Jann Horn Signed-off-by: John Johansen --- security/apparmor/include/cred.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'security/apparmor/include') diff --git a/security/apparmor/include/cred.h b/security/apparmor/include/cred.h index e287b7d0d4be..265ae6641a06 100644 --- a/security/apparmor/include/cred.h +++ b/security/apparmor/include/cred.h @@ -151,6 +151,8 @@ static inline struct aa_label *begin_current_label_crit_section(void) { struct aa_label *label = aa_current_raw_label(); + might_sleep(); + if (label_is_stale(label)) { label = aa_get_newest_label(label); if (aa_replace_current_label(label) == 0) -- cgit v1.2.3