From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5C4734A015F for ; Thu, 24 Sep 2026 15:31:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790263875; cv=none; b=MFq7RmnqEUFb46xXtuh0RsygeZyMD5NqW55oOX43e1udbX0yI8vo9nDDbyS8rNdU9sRIqry4nfMn1SYhddoo2XZ+z5YI2LmWnhuka+0uTVHMFc5coWwMk58HCwj5qOMoy8LUlLablk/X7ajLf9r/H/DJGovz8H5hmg8jPXF9XTk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790263875; c=relaxed/simple; bh=acy2heI6N5U+Wui3WULIgIdoWTLUendu3EBIFa2RjeQ=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=oPXI17/QJPO6PDRoAy/TkGCOE9RC9hBf7CCa0GvNoQWI4R7KQwQs8qhDjWs7cpvgZYuHyBJg1Hs9yy8XEzmld3VKehZh9EPHX8n7WHsoX8o305yrOclxtLI4/U/JbC/kUsfpHcsFZdsCUC+AjgKjhGrxvZrXFBZWp7ZlvwtIc+c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=O9hC7rO4; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="O9hC7rO4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7ACB11F00893; Thu, 24 Sep 2026 15:31:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790263873; bh=xVNY8mR2E446Poqz3twhmU6U0li5O8gCU2Zp2p25HfM=; h=From:To:Cc:Subject:Date:Reply-To; b=O9hC7rO4q796FyMDCp4muLRUF+lig9xXMjyBnZcOEUamKa+CJcOJY5QlKtLJ9ZD/A zEnm5qjLk1raofmjLvY2eGYCHfU6cwyk44WBggcSPigmQDhsnezfW3rwoH/VeMm2Lz XBS2Lj0QvP6kZpFFjnxCGXMMu11lyFZs92yXBLhI= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-93226: ipv6: use RCU iterator to dump route exceptions Date: Thu, 24 Sep 2026 17:28:42 +0200 Message-ID: <2026092441-CVE-2026-93226-6981@gregkh> X-Mailer: git-send-email 2.55.0 Reply-To: , Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=4896; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=Xs/QgadeObIPmZ8evvjtewdguVnw+jHVHB1GDBT2Omk=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlbHVeGL3oU0P6n9b2AoOtbB7WTpW3BCRk2z00tV0SYt tdX6Kd3xLIwCDIxyIopsnzZxnN0f8UhRS9D29Mwc1iZQIYwcHEKwEQ0Kxnmp+V+FHGX+/Fh0bGf NSoad7rzd1T4M8x3u/vi3/kHjH97v6yVYZo985COsnEGAA== X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: ipv6: use RCU iterator to dump route exceptions rt6_nh_dump_exceptions() uses hlist_for_each_entry() to iterate over RCU-protected exception lists. The caller holds rcu_read_lock(), but does not hold rt6_exception_lock, so rt6_insert_exception() can concurrently add an entry with hlist_add_head_rcu(). KCSAN reports this race (irrelevant details omitted): ================================================================== BUG: KCSAN: data-race in rt6_insert_exception / rt6_nh_dump_exceptions write (marked) to 0xffff8a7c44c59620 of 8 bytes by interrupt on cpu 5: rt6_insert_exception+0x3bb/0x760 __ip6_rt_update_pmtu+0x4fe/0x750 ip6_sk_update_pmtu+0x19a/0x3b0 udpv6_err+0x3ff/0x800 icmpv6_notify+0x1e1/0x440 icmpv6_rcv+0x8c0/0xab0 ip6_protocol_deliver_rcu+0x616/0x840 ip6_input_finish+0xb9/0x160 ... entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff8a7c44c59620 of 8 bytes by task 549 on cpu 14: rt6_nh_dump_exceptions+0xb3/0x260 rt6_dump_route+0x53e/0x5f0 fib6_dump_node+0x6d/0xf0 fib6_walk_continue+0x290/0x2d0 fib6_dump_table+0x28d/0x360 inet6_dump_fib+0x37d/0x620 rtnl_dumpit+0x7b/0xd0 netlink_dump+0x3ae/0x7e0 ... entry_SYSCALL_64_after_hwframe+0x77/0x7f 4 locks held by dumper/549: ... #1: (rcu_read_lock){....}-{1:3}, at: inet6_dump_fib+0x88/0x620 #2: (&tb->tb6_lock){+.-.}-{3:3}, at: fib6_dump_table+0x1e9/0x360 #3: (rcu_read_lock){....}-{1:3}, at: rt6_dump_route+0x483/0x5f0 value changed: 0xffff8a7c44e05700 -> 0xffff8a7c45d60100 Reported by Kernel Concurrency Sanitizer on: CPU: 14 UID: 0 PID: 549 Comm: dumper Not tainted 7.2.0-rc7-virtme #38 PREEMPT(lazy) ... Use hlist_for_each_entry_rcu() to safely iterate over the exception list. The Linux kernel CVE team has assigned CVE-2026-93226 to this issue. Affected and fixed versions =========================== Issue introduced in 5.3 with commit 1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9 and fixed in 5.10.270 with commit dffbfb3117138e8e0e09d05f507bd36ca1f696e5 Issue introduced in 5.3 with commit 1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9 and fixed in 5.15.221 with commit 6bd3f94ed858f2d072627546b4cdf712b0f8ea88 Issue introduced in 5.3 with commit 1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9 and fixed in 6.1.188 with commit 9c6be625e1a7258e845d6193b3b6b084a00f8e9e Issue introduced in 5.3 with commit 1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9 and fixed in 6.6.157 with commit 3665abc3d2ae8a78cb67f858e848481432ec75db Issue introduced in 5.3 with commit 1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9 and fixed in 6.12.109 with commit eda56ee17713f9dd834b922f7dbfa2e25fa6358c Issue introduced in 5.3 with commit 1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9 and fixed in 6.18.50 with commit a602cd128d17a793e12888edc8eda85821ede7e1 Issue introduced in 5.3 with commit 1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9 and fixed in 7.2.4 with commit f6b1b15848fd91fe122dac0d19d3d666e35075b6 Issue introduced in 5.3 with commit 1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9 and fixed in 7.3-rc1 with commit 47cdab0d51aaa9bd85f8e4904585bd5bd4df4488 Please see https://www.kernel.org for a full list of currently supported kernel versions by the kernel community. Unaffected versions might change over time as fixes are backported to older supported kernel versions. The official CVE entry at https://cve.org/CVERecord/?id=CVE-2026-93226 will be updated if fixes are backported, please check that for the most up to date information about this issue. Affected files ============== The file(s) affected by this issue are: net/ipv6/route.c Mitigation ========== The Linux kernel CVE team recommends that you update to the latest stable kernel version for this, and many other bugfixes. Individual changes are never tested alone, but rather are part of a larger kernel release. Cherry-picking individual commits is not recommended or supported by the Linux kernel community at all. If however, updating to the latest release is impossible, the individual changes to resolve this issue can be found at these commits: https://git.kernel.org/stable/c/dffbfb3117138e8e0e09d05f507bd36ca1f696e5 https://git.kernel.org/stable/c/6bd3f94ed858f2d072627546b4cdf712b0f8ea88 https://git.kernel.org/stable/c/9c6be625e1a7258e845d6193b3b6b084a00f8e9e https://git.kernel.org/stable/c/3665abc3d2ae8a78cb67f858e848481432ec75db https://git.kernel.org/stable/c/eda56ee17713f9dd834b922f7dbfa2e25fa6358c https://git.kernel.org/stable/c/a602cd128d17a793e12888edc8eda85821ede7e1 https://git.kernel.org/stable/c/f6b1b15848fd91fe122dac0d19d3d666e35075b6 https://git.kernel.org/stable/c/47cdab0d51aaa9bd85f8e4904585bd5bd4df4488