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@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Pavel Skripkin <paskripkin@xxxxxxxxx>
---
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 c0477bec09bd..f2efaa4225f9 100644
--- a/net/qrtr/qrtr.c
+++ b/net/qrtr/qrtr.c
@@ -436,7 +436,7 @@ int qrtr_endpoint_post(struct qrtr_endpoint *ep, const void *data, size_t len)
struct qrtr_sock *ipc;
struct sk_buff *skb;
struct qrtr_cb *cb;
- unsigned int size;
+ size_t size;
unsigned int ver;
size_t hdrlen;
--
2.32.0
