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 7A285433BCA; Tue, 21 Jul 2026 22:12:29 +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=1784671950; cv=none; b=R44MkseX2/Iu6VO+pTbspRTi4Xy7bc0pd1KSAqJblP/ZX6w68rzvUP7eDDqJ+vhaENb7T6SGX6ifv1+E4/6J2rea2cGC0jkugVWG00UynvUf+L7tfcpf9Lamzu0w4nbIgpGuwgnEkNklLogIrqfg6fnCuGX0MN8VpMhh5hfLhuo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784671950; c=relaxed/simple; bh=vtkBzkRbU/ZQH2D0WAWuZpVaQbi88b77GJ6PX9g0ERI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dSIuxsWXAMwuxag+XskcXtgqBe1TrQcrmhe7PwVzhrk5aKWyJdH3q6JlMS79f12G7dt78y2RBNCqvrXcGPM4UgQwxnZiIhM7iaWqw38Xy/HyV41ExhkPZ6P0CT02ai0dYt1PSysqdduk1lh095PgFs1q7buU1ZtZsQTTNwcG1Cg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=XPlgP2A8; 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="XPlgP2A8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D87B81F000E9; Tue, 21 Jul 2026 22:12:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784671949; bh=uiu2KbBxXrDFRWncJk7v7fhjuniM8DSpcYKHWY7Sznw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=XPlgP2A8pld+Q+ta9EulNeupqJvf1BOrkoY18YP3maka9BO30zc5ST1lJPAkjAPZB TWlWMv6I29GA3v23dmWYQ8w3Sl4m3S610ffuvfTlXngYzcGinq0LVQP76UDdNmv0d/ AF1G/r4RRZ0kPbf0kjrRX4294tSOk1/xOfSIntdw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+9383b1ff0df4b29ca5e6@syzkaller.appspotmail.com, Eric Dumazet , Steffen Klassert , Sasha Levin Subject: [PATCH 5.15 439/843] xfrm: validate selector family and prefixlen during match Date: Tue, 21 Jul 2026 17:21:14 +0200 Message-ID: <20260721152415.906007867@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152405.946368001@linuxfoundation.org> References: <20260721152405.946368001@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 40f0b1047918539f0b0f795ac65e35336b4c2c78 ] syzbot reported a shift-out-of-bounds in xfrm_selector_match() due to AF_UNSPEC selector with large prefixlen (e.g. 128) matched against IPv4 flow (when XFRM_STATE_AF_UNSPEC is set). Fix this by: - Rejecting mismatched families in xfrm_selector_match. - Returning false in addr4_match if prefixlen > 32. - Returning false in addr_match if prefixlen > 128 (prevents overflow). Fixes: 3f0ab59e6537 ("xfrm: validate new SA's prefixlen using SA family when sel.family is unset") Reported-by: syzbot+9383b1ff0df4b29ca5e6@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6a2fbe35.be3f099c.2836ae.0018.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin --- include/net/xfrm.h | 7 +++++++ net/xfrm/xfrm_policy.c | 3 +++ 2 files changed, 10 insertions(+) diff --git a/include/net/xfrm.h b/include/net/xfrm.h index a042f130f99b6e..e94009c632dfae 100644 --- a/include/net/xfrm.h +++ b/include/net/xfrm.h @@ -812,6 +812,9 @@ static inline bool addr_match(const void *token1, const void *token2, unsigned int pdw; unsigned int pbi; + if (prefixlen > 128) + return false; + pdw = prefixlen >> 5; /* num of whole u32 in prefix */ pbi = prefixlen & 0x1f; /* num of bits in incomplete u32 in prefix */ @@ -836,6 +839,10 @@ static inline bool addr4_match(__be32 a1, __be32 a2, u8 prefixlen) /* C99 6.5.7 (3): u32 << 32 is undefined behaviour */ if (sizeof(long) == 4 && prefixlen == 0) return true; + + if (prefixlen > 32) + return false; + return !((a1 ^ a2) & htonl(~0UL << (32 - prefixlen))); } diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index d8348730e2d0e6..cec66c74e1d22a 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -223,6 +223,9 @@ __xfrm6_selector_match(const struct xfrm_selector *sel, const struct flowi *fl) bool xfrm_selector_match(const struct xfrm_selector *sel, const struct flowi *fl, unsigned short family) { + if (family != sel->family && sel->family != AF_UNSPEC) + return false; + switch (family) { case AF_INET: return __xfrm4_selector_match(sel, fl); -- 2.53.0