From: Pavel Skripkin
stable inclusion
from linux-4.19.196
commit f8111c0d7ed42ede41a3d0d393b104de0730a8a6
category: bugfix
issue: #I4CC5E
CVE: CVE-2021-3743
--------------------------------
[ Upstream commit ad9d24c9429e2159d1e279dc3a83191ccb4daf1d ]
Syzbot reported slab-out-of-bounds Read in
qrtr_endpoint_post. The problem was in wrong
_size_ type:
if (len != ALIGN(size, 4) + hdrlen)
goto err;
If size from qrtr_hdr is 4294967293 (0xfffffffd), the result of
ALIGN(size, 4) will be 0. In case of len == hdrlen and size == 4294967293
in header this check won't fail and
skb_put_data(skb, data + hdrlen, size);
will read out of bound from data, which is hdrlen allocated block.
Fixes: 194ccc88297a ("net: qrtr: Support decoding incoming v2 packets")
Reported-and-tested-by: syzbot+1917d778024161609247@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin
Reviewed-by: Bjorn Andersson
Signed-off-by: David S. Miller
Signed-off-by: Sasha Levin
Signed-off-by: Yang Yingliang
Reviewed-by: Xiu Jianfeng
Reviewed-by: Yue Haibing
Signed-off-by: Yang Yingliang
Signed-off-by: Yu Changchun
---
net/qrtr/qrtr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c
index 5d152de50dff..4c7ae7155078 100644
--- a/net/qrtr/qrtr.c
+++ b/net/qrtr/qrtr.c
@@ -264,7 +264,7 @@ int qrtr_endpoint_post(struct qrtr_endpoint *ep, const void *data, size_t len)
const struct qrtr_hdr_v2 *v2;
struct sk_buff *skb;
struct qrtr_cb *cb;
- unsigned int size;
+ size_t size;
unsigned int ver;
size_t hdrlen;
--
2.22.0
