xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

apparmor: don't try to replace stale label in ptrace access check

Browse Source 
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: b2d09ae449 ("apparmor: move ptrace checks to using labels")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
This commit is contained in:
Jann Horn
2018-09-13 18:12:09 +02:00
committed by John Johansen
parent 5f997580e8
commit 1f8266ff58
2 changed files with 4 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
security/apparmor/include/cred.h
View File

@@ -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)