Date: Sat, 18 Feb 2023 11:55:48 GMT From: "Alexander V. Chernikov" <melifaro@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 13e997289240 - stable/13 - netlink: Zero-initialize mbuf messages Message-ID: <202302181155.31IBtmeQ069527@gitrepo.freebsd.org>
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The branch stable/13 has been updated by melifaro: URL: https://cgit.FreeBSD.org/src/commit/?id=13e997289240c4697536f904167720a29abf7a58 commit 13e997289240c4697536f904167720a29abf7a58 Author: Mark Johnston <markj@FreeBSD.org> AuthorDate: 2023-01-17 14:36:54 +0000 Commit: Alexander V. Chernikov <melifaro@FreeBSD.org> CommitDate: 2023-02-18 11:53:54 +0000 netlink: Zero-initialize mbuf messages 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 Reviewed by: melifaro Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D38098 (cherry picked from commit d91be0f1211b0196a0087cdfa237a6a0d2a43b65) --- sys/netlink/netlink_message_writer.c | 1 + 1 file changed, 1 insertion(+) diff --git a/sys/netlink/netlink_message_writer.c b/sys/netlink/netlink_message_writer.c index 37414703c6f6..6573394eb881 100644 --- a/sys/netlink/netlink_message_writer.c +++ b/sys/netlink/netlink_message_writer.c @@ -215,6 +215,7 @@ nlmsg_get_ns_mbuf(struct nl_writer *nw, int size, bool waitok) nw->malloc_flag = mflag; nw->num_messages = 0; nw->enomem = false; + memset(nw->data, 0, size); NL_LOG(LOG_DEBUG2, "alloc mbuf %p req_len %d alloc_len %d data_ptr %p", m, size, nw->alloc_len, nw->data); return (true);
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