[PATCH 5.15 033/171] nfc: fix potential NULL pointer deref in nfc_genl_dump_ses_done

Greg Kroah-Hartman
2021-12-13T09:59:27Z

From: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

commit 4cd8371a234d051f9c9557fcbb1f8c523b1c0d10 upstream.

The done() netlink callback nfc_genl_dump_ses_done() should check if
received argument is non-NULL, because its allocation could fail earlier
in dumpit() (nfc_genl_dump_ses()).

Fixes: ac22ac466a65 ("NFC: Add a GET_SE netlink API")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20211209081307.57337-1-krzysztof.kozlowski@canonical.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/nfc/netlink.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

--- a/net/nfc/netlink.c
+++ b/net/nfc/netlink.c
@@ -1392,8 +1392,10 @@ static int nfc_genl_dump_ses_done(struct
{
struct class_dev_iter *iter = (struct class_dev_iter *) cb->args[0];

- nfc_device_iter_exit(iter);
- kfree(iter);
+ if (iter) {
+ nfc_device_iter_exit(iter);
+ kfree(iter);
+ }

return 0;
}