From 4b4f0b12c48b92ce1b63311b5dba5284b896b947 Mon Sep 17 00:00:00 2001 From: "akpm@osdl.org" Date: Fri, 29 Apr 2005 18:01:08 -0700 Subject: [PATCH] Fix reproducible SMP crash in security/keys/key.c Jani Jaakkola wrote: > > SMP race handling is broken in key_user_lookup() in security/keys/key.c This was fixed post-2.6.11. Can you confirm that 2.6.12-rc2 works OK? This is the patch we used. It should go into -stable if it's not already there. From: Alexander Nyberg I looked at some of the oops reports against keyrings, I think the problem is that the search isn't restarted after dropping the key_user_lock, *p will still be NULL when we get back to try_again and look through the tree. It looks like the intention was that the search start over from scratch. Signed-off-by: Alexander Nyberg Cc: David Howells Signed-off-by: Andrew Morton Signed-off-by: Chris Wright Signed-off-by: Greg Kroah-Hartman --- security/keys/key.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/security/keys/key.c b/security/keys/key.c index e3d0359f5f7e..59402c843203 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -57,9 +57,10 @@ struct key_user *key_user_lookup(uid_t uid) { struct key_user *candidate = NULL, *user; struct rb_node *parent = NULL; - struct rb_node **p = &key_user_tree.rb_node; + struct rb_node **p; try_again: + p = &key_user_tree.rb_node; spin_lock(&key_user_lock); /* search the tree for a user record with a matching UID */ -- cgit v1.2.3