[PATCH] fix filp_cachep memory corruption

From: J. R. Okajima
Date: Wed Feb 02 2011 - 14:19:11 EST



commit e1ddf5b0dd3e8234581c78c3cadd6e2adfe6e2d4
Author: J. R. Okajima <hooanon05@xxxxxxxxxxx>
Date: Thu Feb 3 03:38:12 2011 +0900

fix filp_cachep memory corruption

By the commit
31e6b01 2011-01-07 fs: rcu-walk for path lookup
the condition "-ESTALE && !LOOKUP_REVAL" is added to "goto reval" in
do_filp_open(), and it lookup again with LOOKUP_REVAL _after_
release_open_intent(). Since release_open_intent() is called by
do_last() and finish_open() too, add the same condition to all of them.

Signed-off-by: J. R. Okajima <hooanon05@xxxxxxxxxxx>

diff --git a/fs/namei.c b/fs/namei.c
index 084be4d..1f62d6a 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2269,7 +2269,8 @@ static struct file *finish_open(struct nameidata *nd,
return filp;

exit:
- if (!IS_ERR(nd->intent.open.file))
+ if (!(error == -ESTALE && !(nd->flags & LOOKUP_REVAL))
+ && !IS_ERR(nd->intent.open.file))
release_open_intent(nd);
path_put(&nd->path);
return ERR_PTR(error);
@@ -2393,7 +2394,8 @@ exit_mutex_unlock:
exit_dput:
path_put_conditional(path, nd);
exit:
- if (!IS_ERR(nd->intent.open.file))
+ if (!(error == -ESTALE && !(nd->flags & LOOKUP_REVAL))
+ && !IS_ERR(nd->intent.open.file))
release_open_intent(nd);
path_put(&nd->path);
return ERR_PTR(error);
@@ -2564,7 +2566,8 @@ exit_dput:
out_path:
path_put(&nd.path);
out_filp:
- if (!IS_ERR(nd.intent.open.file))
+ if (!(error == -ESTALE && !(flags & LOOKUP_REVAL))
+ && !IS_ERR(nd.intent.open.file))
release_open_intent(&nd);
filp = ERR_PTR(error);
goto out;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/