Date: Mon, 3 Jul 2023 19:32:51 GMT From: Kristof Provost <kp@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: d0b0424fa0ca - main - altq codel: do not insert the same mtag twice Message-ID: <202307031932.363JWpfC048006@gitrepo.freebsd.org>
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The branch main has been updated by kp: URL: https://cgit.FreeBSD.org/src/commit/?id=d0b0424fa0ca8fb239e00d6bdd5e6340b7a85e68 commit d0b0424fa0ca8fb239e00d6bdd5e6340b7a85e68 Author: Kristof Provost <kp@FreeBSD.org> AuthorDate: 2023-07-03 17:02:23 +0000 Commit: Kristof Provost <kp@FreeBSD.org> CommitDate: 2023-07-03 19:32:33 +0000 altq codel: do not insert the same mtag twice If we're called on an mbuf that's passed through codel before it may already contain the MTAG_CODEL tag. The code accounts for this and does not allocate a new mtag. However, it inserts the mtag unconditionally. That is, it inserts the existing mtag a second time. When the mbuf later gets freed we iterate over the list of mtags to fee them one by one, and we'll end up freeing an mtag that's already been freed. Only insert the mtag if we've allocated a new one. If we found one there's no need to insert it again. See also: https://redmine.pfsense.org/issues/14497 Sponsored by: Rubicon Communications, LLC ("Netgate") --- sys/net/altq/altq_codel.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/sys/net/altq/altq_codel.c b/sys/net/altq/altq_codel.c index be16a5aef3e5..5006920ca68d 100644 --- a/sys/net/altq/altq_codel.c +++ b/sys/net/altq/altq_codel.c @@ -289,16 +289,18 @@ codel_addq(struct codel *c, class_queue_t *q, struct mbuf *m) if (qlen(q) < qlimit(q)) { mtag = m_tag_locate(m, MTAG_CODEL, 0, NULL); - if (mtag == NULL) + if (mtag == NULL) { mtag = m_tag_alloc(MTAG_CODEL, 0, sizeof(uint64_t), M_NOWAIT); + if (mtag != NULL) + m_tag_prepend(m, mtag); + } if (mtag == NULL) { m_freem(m); return (-1); } enqueue_time = (uint64_t *)(mtag + 1); *enqueue_time = read_machclk(); - m_tag_prepend(m, mtag); _addq(q, m); return (0); }
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