francis.wang
4c86c082a2
Combine poky (Yocto scarthgap), meta-openembedded (scarthgap), and meta-openwrt into a single repository. Components: - poky/ Yocto core framework (BitBake + OE-Core) - meta-openembedded/ Community layers (meta-oe, meta-python, meta-networking) - meta-openwrt/ OpenWrt customization layer - setup-env.sh One-click build environment setup - README.md Project documentation
39 lines
1.4 KiB
Diff
39 lines
1.4 KiB
Diff
From 262aadd7a38947d2299234c8c9cf736ff6ad955d Mon Sep 17 00:00:00 2001
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From: Simon Kelley <simon@thekelleys.org.uk>
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Date: Wed, 25 Mar 2026 23:22:37 +0000
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Subject: [PATCH] Fix broken client subnet validation. CVE-2026-4893
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Bug report from Royce M <royce@xchglabs.com>
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Location: forward.c:713, edns0.c:421
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With --add-subnet enabled, process_reply() passes the OPT record
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length (~23 bytes) instead of the packet length to check_source().
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All internal bounds checks fail, and the function always returns 1.
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ECS source validation per RFC 7871 Section 9.2 is completely bypassed.
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CVE: CVE-2026-4893
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Upstream-Status: Backport [https://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=commit;h=e3a26d092e47bf1d18aeadb758e4ca35c83b5f2d]
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Signed-off-by: Hugo SIMELIERE (Schneider Electric) <hsimeliere.opensource@witekio.com>
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---
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src/forward.c | 2 +-
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1 file changed, 1 insertion(+), 1 deletion(-)
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diff --git a/src/forward.c b/src/forward.c
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index 32f37e40..19ff4401 100644
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--- a/src/forward.c
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+++ b/src/forward.c
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@@ -710,7 +710,7 @@ static size_t process_reply(struct dns_header *header, time_t now, struct server
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/* Get extended RCODE. */
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rcode |= sizep[2] << 4;
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- if (option_bool(OPT_CLIENT_SUBNET) && !check_source(header, plen, pheader, query_source))
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+ if (option_bool(OPT_CLIENT_SUBNET) && !check_source(header, n, pheader, query_source))
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{
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my_syslog(LOG_WARNING, _("discarding DNS reply: subnet option mismatch"));
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return 0;
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--
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2.43.0
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