[PATCH 6.1 065/131] nfc: nci: assert requested protocol is valid

Greg Kroah-Hartman
2023-10-16T09:01:26Z

From: Jeremy Cline <jeremy@jcline.org>

[ Upstream commit 354a6e707e29cb0c007176ee5b8db8be7bd2dee0 ]

The protocol is used in a bit mask to determine if the protocol is
supported. Assert the provided protocol is less than the maximum
defined so it doesn't potentially perform a shift-out-of-bounds and
provide a clearer error for undefined protocols vs unsupported ones.

Fixes: 6a2968aaf50c ("NFC: basic NCI protocol implementation")
Reported-and-tested-by: syzbot+0839b78e119aae1fec78@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=0839b78e119aae1fec78
Signed-off-by: Jeremy Cline <jeremy@jcline.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20231009200054.82557-1-jeremy@jcline.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/nfc/nci/core.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index 4ffdf2f45c444..7535afd1537e9 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -908,6 +908,11 @@ static int nci_activate_target(struct nfc_dev *nfc_dev,
return -EINVAL;
}

+ if (protocol >= NFC_PROTO_MAX) {
+ pr_err("the requested nfc protocol is invalid\n");
+ return -EINVAL;
+ }
+
if (!(nci_target->supported_protocols & (1 << protocol))) {
pr_err("target does not support the requested protocol 0x%x\n",
protocol);
--
2.40.1