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authorJesper Juhl <jj@chaosbits.net>2010-12-25 21:22:30 +0000
committerChris Mason <chris.mason@oracle.com>2011-01-16 11:30:20 -0500
commitff175d57f057f77d2d3031d674c2af9167a4af02 (patch)
treeff04961d44566d7abc3ea4aab888900d40561c3e
parent20b450773d17e325190c158e10bfdb25dc21d2d6 (diff)
btrfs: Don't pass NULL ptr to func that may deref it.
Hi, In fs/btrfs/inode.c::fixup_tree_root_location() we have this code: ... if (!path) { err = -ENOMEM; goto out; } ... out: btrfs_free_path(path); return err; btrfs_free_path() passes its argument on to other functions and some of them end up dereferencing the pointer. In the code above that pointer is clearly NULL, so btrfs_free_path() will eventually cause a NULL dereference. There are many ways to cut this cake (fix the bug). The one I chose was to make btrfs_free_path() deal gracefully with NULL pointers. If you disagree, feel free to come up with an alternative patch. Signed-off-by: Jesper Juhl <jj@chaosbits.net> Signed-off-by: Chris Mason <chris.mason@oracle.com>
-rw-r--r--fs/btrfs/ctree.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 9ac171599258..99599f1c1554 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -105,6 +105,8 @@ noinline void btrfs_clear_path_blocking(struct btrfs_path *p,
/* this also releases the path */
void btrfs_free_path(struct btrfs_path *p)
{
+ if (!p)
+ return;
btrfs_release_path(NULL, p);
kmem_cache_free(btrfs_path_cachep, p);
}