From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julia Lawall Subject: [PATCH] fs/btrfs: Correct use after free Date: Sun, 28 Mar 2010 18:00:25 +0200 (CEST) Message-ID: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII To: Chris Mason , linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Return-path: List-ID: From: Julia Lawall If the kfree is executed, the dereference of range afterwards will represent a use after free. Added goto out, as done in the other nearby error handling code. A simplified version of the semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // @@ expression x,e; identifier f; iterator I; statement S; @@ *kfree(x); ... when != &x when != x = e when != I(x,...) S *x->f // Signed-off-by: Julia Lawall --- fs/btrfs/ioctl.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 2845c6c..dacbb52 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1375,6 +1375,7 @@ static int btrfs_ioctl_defrag(struct file *file, void __user *argp) sizeof(*range))) { ret = -EFAULT; kfree(range); + goto out; } /* compression requires us to start the IO */ if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {