Messages in this thread Patch in this message | | | Date | Sun, 28 Mar 2010 18:00:25 +0200 (CEST) | From | Julia Lawall <> | Subject | [PATCH] fs/btrfs: Correct use after free |
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From: Julia Lawall <julia@diku.dk>
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/)
// <smpl> @@ expression x,e; identifier f; iterator I; statement S; @@
*kfree(x); ... when != &x when != x = e when != I(x,...) S *x->f // </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
--- 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)) {
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