[PATCH 4.9 16/35] dump_common_audit_data(): fix racy accesses to ->d_name

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

commit d36a1dd9f77ae1e72da48f4123ed35627848507d upstream.

We are not guaranteed the locking environment that would prevent
dentry getting renamed right under us.  And it's possible for
old long name to be freed after rename, leading to UAF here.

Cc: stable@xxxxxxxxxx # v2.6.2+
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 security/lsm_audit.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/security/lsm_audit.c
+++ b/security/lsm_audit.c
@@ -277,7 +277,9 @@ static void dump_common_audit_data(struc
 		struct inode *inode;
 
 		audit_log_format(ab, " name=");
+		spin_lock(&a->u.dentry->d_lock);
 		audit_log_untrustedstring(ab, a->u.dentry->d_name.name);
+		spin_unlock(&a->u.dentry->d_lock);
 
 		inode = d_backing_inode(a->u.dentry);
 		if (inode) {
@@ -295,8 +297,9 @@ static void dump_common_audit_data(struc
 		dentry = d_find_alias(inode);
 		if (dentry) {
 			audit_log_format(ab, " name=");
-			audit_log_untrustedstring(ab,
-					 dentry->d_name.name);
+			spin_lock(&dentry->d_lock);
+			audit_log_untrustedstring(ab, dentry->d_name.name);
+			spin_unlock(&dentry->d_lock);
 			dput(dentry);
 		}
 		audit_log_format(ab, " dev=");





[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux