Messages in this thread Patch in this message | | | Date | Wed, 13 Apr 2005 02:02:46 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] Fix reproducible SMP crash in security/keys/key.c |
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Jani Jaakkola <jjaakkol@cs.Helsinki.FI> 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 <alexn@dsv.su.se>
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 <alexn@dsv.su.se> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> ---
25-akpm/security/keys/key.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletion(-)
diff -puN security/keys/key.c~race-against-parent-deletion-in-key_user_lookup security/keys/key.c --- 25/security/keys/key.c~race-against-parent-deletion-in-key_user_lookup 2005-03-10 00:38:38.000000000 -0800 +++ 25-akpm/security/keys/key.c 2005-03-10 00:38:38.000000000 -0800 @@ -57,9 +57,10 @@ struct key_user *key_user_lookup(uid_t u { 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 */ _ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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