[PATCH v5 01/11] net: qrtr: ns: validate msglen before ctrl_pkt use

[Mihai Moldovan <ionic@ionic.de>]

From: Denis Kenzior <denkenz@gmail.com>

The qrtr_ctrl_pkt structure is currently accessed without checking
if the received payload is large enough to hold the structure's fields.
Add a check to ensure the payload length is sufficient.

Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Andy Gross <agross@kernel.org>
Signed-off-by: Mihai Moldovan <ionic@ionic.de>
Fixes: 0c2204a4ad71 ("net: qrtr: Migrate nameservice to kernel from userspace")

---
v5:
  - no changes
  - Link to v4: https://msgid.link/456d8dff226c88657c79f1dbadf0dcaba8b905ae.1753720934.git.ionic@ionic.de

v4:
  - no changes
  - Link to v3: https://msgid.link/a3bc13d1496404e96723a427086271107016bdd6.1753312999.git.ionic@ionic.de

v3:
  - add Fixes: tag
  - rebase against current master
  - Link to v2: https://msgid.link/866f309e9739d770dce7e8c648b562d37db1d8b5.1752947108.git.ionic@ionic.de

v2:
  - rebase against current master
  - use correct size of packet structure as per review comment
  - Link to v1: https://msgid.link/20241018181842.1368394-2-denkenz@gmail.com
---
 net/qrtr/ns.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/qrtr/ns.c b/net/qrtr/ns.c
index 3de9350cbf30..2bcfe539dc3e 100644
--- a/net/qrtr/ns.c
+++ b/net/qrtr/ns.c
@@ -619,6 +619,9 @@ static void qrtr_ns_worker(struct work_struct *work)
 			break;
 		}
 
+		if ((size_t)msglen < sizeof(*pkt))
+			break;
+
 		pkt = recv_buf;
 		cmd = le32_to_cpu(pkt->cmd);
 		if (cmd < ARRAY_SIZE(qrtr_ctrl_pkt_strings) &&
-- 
2.50.0