CVE-2022-50656

In the Linux kernel, the following vulnerability has been resolved:

nfc: pn533: Clear nfc_target before being used

Fix a slab-out-of-bounds read that occurs in nla_put() called from nfc_genl_send_target() when target->sensb_res_len, which is duplicated from an nfc_target in pn533, is too large as the nfc_target is not properly initialized and retains garbage values. Clear nfc_targets with memset() before they are used.

Found by a modified version of syzkaller.

BUG: KASAN: slab-out-of-bounds in nla_put Call Trace: memcpy nla_put nfc_genl_dump_targets genl_lock_dumpit netlink_dump __netlink_dump_start genl_family_rcv_msg_dumpit genl_rcv_msg netlink_rcv_skb genl_rcv netlink_unicast netlink_sendmsg sock_sendmsg ____sys_sendmsg ___sys_sendmsg __sys_sendmsg do_syscall_64

Red Hat Enterprise Linux is not affected by this flaw because the PN533 Near Field Communication (NFC) driver is not enabled or compiled in supported kernel packages. Triggering this out-of-bounds read requires an active PN533 device and the processing of netlink dump requests against uninitialized target structures. Because this hardware subsystem is omitted from default enterprise kernels, the vulnerability presents no operational risk to Red Hat environments.