This is a note to let you know that I've just added the patch titled nfc: Ensure presence of required attributes in the activate_target handler to the 4.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: nfc-ensure-presence-of-required-attributes-in-the-activate_target-handler.patch and it can be found in the queue-4.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From a0323b979f81ad2deb2c8836eab506534891876a Mon Sep 17 00:00:00 2001 From: Mateusz Jurczyk <mjurczyk@xxxxxxxxxx> Date: Wed, 24 May 2017 12:42:26 +0200 Subject: nfc: Ensure presence of required attributes in the activate_target handler From: Mateusz Jurczyk <mjurczyk@xxxxxxxxxx> commit a0323b979f81ad2deb2c8836eab506534891876a upstream. Check that the NFC_ATTR_TARGET_INDEX and NFC_ATTR_PROTOCOLS attributes (in addition to NFC_ATTR_DEVICE_INDEX) are provided by the netlink client prior to accessing them. This prevents potential unhandled NULL pointer dereference exceptions which can be triggered by malicious user-mode programs, if they omit one or both of these attributes. Signed-off-by: Mateusz Jurczyk <mjurczyk@xxxxxxxxxx> Acked-by: Kees Cook <keescook@xxxxxxxxxxxx> Signed-off-by: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/nfc/netlink.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/net/nfc/netlink.c +++ b/net/nfc/netlink.c @@ -907,7 +907,9 @@ static int nfc_genl_activate_target(stru u32 device_idx, target_idx, protocol; int rc; - if (!info->attrs[NFC_ATTR_DEVICE_INDEX]) + if (!info->attrs[NFC_ATTR_DEVICE_INDEX] || + !info->attrs[NFC_ATTR_TARGET_INDEX] || + !info->attrs[NFC_ATTR_PROTOCOLS]) return -EINVAL; device_idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]); Patches currently in stable-queue which might be from mjurczyk@xxxxxxxxxx are queue-4.12/nfc-add-sockaddr-length-checks-before-accessing-sa_family-in-bind-handlers.patch queue-4.12/nfc-ensure-presence-of-required-attributes-in-the-activate_target-handler.patch queue-4.12/nfc-fix-the-sockaddr-length-sanitization-in-llcp_sock_connect.patch