Change Details

Some users of nlmsg_reserve_object() and nlmsg_reserve_data() are not careful to fully initialize pad and reserved fields, allowing uninitialized bytes to leak to userspace. For example, dump_nhgrp() doesn't set nhm->resvd = 0. Meanwhile, nlmsg_get_ns_buf() and nlmsg_get_ns_lbuf() zero-initialize the buffer, so nlmsg_get_ns_mbuf() is inconsistent. Let's just make them all behave the same here.

Some users of nlmsg_reserve_object() and nlmsg_reserve_data() are not careful to fully initialize pad and reserved fields, allowing uninitialized bytes to leak to userspace. For example, dump_nhgrp() doesn't set nhm->resvd = 0. Meanwhile, nlmsg_get_ns_buf() and nlmsg_get_ns_lbuf() zero-initialize the buffer, so nlmsg_get_ns_mbuf() is inconsistent. Let's just make them all behave the same here. Reported by: KMSAN

Some users of nlmsg_reserve_object() and nlmsg_reserve_data() are not careful to fully initialize pad and reserved fields, allowing uninitialized bytes to leak to userspace. For example, dump_nhgrp() doesn't set nhm->resvd = 0. Meanwhile, nlmsg_get_ns_buf() and nlmsg_get_ns_lbuf() zero-initialize the buffer, so nlmsg_get_ns_mbuf() is inconsistent. Let's just make them all behave the same here. Reported by: KMSAN