From: Oleg Drokin <green@linuxhacker.ru>
Date: Fri, 15 Aug 2014 16:48:13 +0000 (-0400)
Subject: staging/lustre/llite: Fix integer overflow in ll_fid2path
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=c7b09efacf54210be511450768c0ee98071feb7f;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

staging/lustre/llite: Fix integer overflow in ll_fid2path

Reported by Dan Carpenter <dan.carpenter@oracle.com>

outsize = sizeof(*gfout) + gfin->gf_pathlen;

Where outsize is int and gf_pathlen is u32 from userspace
can lead to integer overflowwhere outsize is some small number
less than sizeof(*gfout)

Add a check for pathlen to be of sensical size.

Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Reviewed-on: http://review.whamcloud.com/11412
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5476
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/staging/lustre/lustre/llite/file.c b/drivers/staging/lustre/lustre/llite/file.c
index d3874e1afba8..4a33638bef25 100644
--- a/drivers/staging/lustre/lustre/llite/file.c
+++ b/drivers/staging/lustre/lustre/llite/file.c
@@ -1719,6 +1719,9 @@ int ll_fid2path(struct inode *inode, void __user *arg)
 	if (get_user(pathlen, &gfin->gf_pathlen))
 		return -EFAULT;
 
+	if (pathlen > PATH_MAX)
+		return -EINVAL;
+
 	outsize = sizeof(*gfout) + pathlen;
 
 	OBD_ALLOC(gfout, outsize);