path: root/security/apparmor/apparmorfs.c
diff options
authorXiyu Yang <>2020-04-20 13:35:28 +0800
committerJohn Johansen <>2020-05-21 15:25:51 -0700
commitc6b39f070722ea9963ffe756bfe94e89218c5e63 (patch)
tree5c8de2d138cd172138ab19c204884366960a6f55 /security/apparmor/apparmorfs.c
parenta0b845ffa0d91855532b50fc040aeb2d8338dca4 (diff)
apparmor: Fix aa_label refcnt leak in policy_update
policy_update() invokes begin_current_label_crit_section(), which returns a reference of the updated aa_label object to "label" with increased refcount. When policy_update() returns, "label" becomes invalid, so the refcount should be decreased to keep refcount balanced. The reference counting issue happens in one exception handling path of policy_update(). When aa_may_manage_policy() returns not NULL, the refcnt increased by begin_current_label_crit_section() is not decreased, causing a refcnt leak. Fix this issue by jumping to "end_section" label when aa_may_manage_policy() returns not NULL. Fixes: 5ac8c355ae00 ("apparmor: allow introspecting the loaded policy pre internal transform") Signed-off-by: Xiyu Yang <> Signed-off-by: Xin Tan <> Signed-off-by: John Johansen <>
Diffstat (limited to 'security/apparmor/apparmorfs.c')
1 files changed, 2 insertions, 1 deletions
diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index 280741fc0f5f..f6a3ecfadf80 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -454,7 +454,7 @@ static ssize_t policy_update(u32 mask, const char __user *buf, size_t size,
error = aa_may_manage_policy(label, ns, mask);
if (error)
- return error;
+ goto end_section;
data = aa_simple_write_to_buffer(buf, size, size, pos);
error = PTR_ERR(data);
@@ -462,6 +462,7 @@ static ssize_t policy_update(u32 mask, const char __user *buf, size_t size,
error = aa_replace_profiles(ns, label, mask, data);
return error;