Date: Fri, 7 May 2021 15:25:57 GMT From: Kristof Provost <kp@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: af1b05bb32b5 - stable/12 - pf: Fix IP checksum on reassembly Message-ID: <202105071525.147FPvsa026797@gitrepo.freebsd.org>
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The branch stable/12 has been updated by kp: URL: https://cgit.FreeBSD.org/src/commit/?id=af1b05bb32b5440dd999853bd7c01a5b8c0d73f4 commit af1b05bb32b5440dd999853bd7c01a5b8c0d73f4 Author: Kristof Provost <kp@FreeBSD.org> AuthorDate: 2021-04-28 10:56:06 +0000 Commit: Kristof Provost <kp@FreeBSD.org> CommitDate: 2021-05-07 08:17:50 +0000 pf: Fix IP checksum on reassembly If we reassemble a packet we modify the IP header (to set the length and remove the fragment offset information), but we failed to update the checksum. On certain setups (mostly where we did not re-fragment again afterwards) this could lead to us sending out packets with incorrect checksums. PR: 255432 MFC after: 1 week Sponsored by: Rubicon Communications, LLC ("Netgate") Differential Revision: https://reviews.freebsd.org/D30026 (cherry picked from commit 055c55abefbe19fe46a56894595af9c9dad7678c) --- sys/netpfil/pf/pf_norm.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/sys/netpfil/pf/pf_norm.c b/sys/netpfil/pf/pf_norm.c index 2a3c1d442fd4..8f970b68373b 100644 --- a/sys/netpfil/pf/pf_norm.c +++ b/sys/netpfil/pf/pf_norm.c @@ -790,7 +790,11 @@ pf_reassemble(struct mbuf **m0, struct ip *ip, int dir, u_short *reason) } ip = mtod(m, struct ip *); + ip->ip_sum = pf_cksum_fixup(ip->ip_sum, ip->ip_len, + htons(hdrlen + total), 0); ip->ip_len = htons(hdrlen + total); + ip->ip_sum = pf_cksum_fixup(ip->ip_sum, ip->ip_off, + ip->ip_off & ~(IP_MF|IP_OFFMASK), 0); ip->ip_off &= ~(IP_MF|IP_OFFMASK); if (hdrlen + total > IP_MAXPACKET) {
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