[kernel] r22395 - in dists/wheezy-security/linux/debian/patches: . bugfix/all

[Ben Hutchings]

Author: benh
Date: Tue Feb 17 04:59:39 2015
New Revision: 22395

Log:
vfs: Fix vfsmount_lock imbalance in path_init() (regression in 3.2.64)

Added:
   dists/wheezy-security/linux/debian/patches/bugfix/all/vfs-fix-vfsmount_lock-imbalance-in-path_init.patch
Modified:
   dists/wheezy-security/linux/debian/patches/series

Added: dists/wheezy-security/linux/debian/patches/bugfix/all/vfs-fix-vfsmount_lock-imbalance-in-path_init.patch
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ dists/wheezy-security/linux/debian/patches/bugfix/all/vfs-fix-vfsmount_lock-imbalance-in-path_init.patch	Tue Feb 17 04:59:39 2015	(r22395)
@@ -0,0 +1,25 @@
+From: Ben Hutchings <ben at decadent.org.uk>
+Date: Mon, 16 Feb 2015 03:21:17 +0000
+Subject: vfs: Fix vfsmount_lock imbalance in path_init()
+
+When backporting commit 4023bfc9f351 ("be careful with nd->inode in
+path_init() and follow_dotdot_rcu()"), I failed to account for the
+vfsmount_lock that is used in 3.2 but not upstream.  path_init() takes
+the lock if performing RCU lookup, but must drop it if (and only if)
+it subsequently fails.
+
+Reported-by: nuxi at vault24.org
+References: https://bugzilla.kernel.org/show_bug.cgi?id=92531
+Signed-off-by: Ben Hutchings <ben at decadent.org.uk>
+Tested-by: nuxi at vault24.org
+---
+--- a/fs/namei.c
++++ b/fs/namei.c
+@@ -1682,6 +1682,7 @@ static int path_init(int dfd, const char
+ 	if (!(nd->flags & LOOKUP_ROOT))
+ 		nd->root.mnt = NULL;
+ 	rcu_read_unlock();
++	br_read_unlock(vfsmount_lock);
+ 	return -ECHILD;
+ 
+ fput_fail:

Modified: dists/wheezy-security/linux/debian/patches/series
==============================================================================
--- dists/wheezy-security/linux/debian/patches/series	Tue Feb 17 04:54:45 2015	(r22394)
+++ dists/wheezy-security/linux/debian/patches/series	Tue Feb 17 04:59:39 2015	(r22395)
@@ -1168,3 +1168,4 @@
 debian/vfs-avoid-abi-change-for-dentry-union-changes.patch
 bugfix/all/vfs-read-file_handle-only-once-in-handle_to_path.patch
 bugfix/all/aslr-fix-stack-randomization-on-64-bit-systems.patch
+bugfix/all/vfs-fix-vfsmount_lock-imbalance-in-path_init.patch