4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jeremy Cline <jeremy@xxxxxxxxxx> [ 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@xxxxxxxxxxxxxxxxxxxxxxxxx Closes: https://syzkaller.appspot.com/bug?extid=0839b78e119aae1fec78 Signed-off-by: Jeremy Cline <jeremy@xxxxxxxxxx> Reviewed-by: Simon Horman <horms@xxxxxxxxxx> Link: https://lore.kernel.org/r/20231009200054.82557-1-jeremy@xxxxxxxxxx Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 216228c39acba..d42c603dd635c 100644 --- a/net/nfc/nci/core.c +++ b/net/nfc/nci/core.c @@ -906,6 +906,11 @@ 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