From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E9633173336; Wed, 3 Jul 2024 10:54:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720004042; cv=none; b=QZE8w2zksaArL0oaBQ1QMseYdjn12KXnvZsyBfVSMC7JUwM11PlCSKs+Q8pgR63DmwxUrHNoqQ9heuovpy7wUdnSDieSOponhDzIejn8M8Uw4KUMNq4QJG04kO8obTOux7Qppt7J7toCEJpUi06wOccf8Y6uNdlHeo4y5tLhfiM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720004042; c=relaxed/simple; bh=Sum860Pf2oIZ/F4xNrN9xauCmYGYUGFfQdjE+mjiu80=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=u4oMRBSOAhpdmvdw3OcKj3gq68aEJNgSrM17dVWn9IpHLkxpWuK7UY+TM6eWO7A6svk70xbI90O+HKpxTQf5D2MHudFYmNuzqCIueqXkmvhVz+1LbkaSFxzaCeOqbsSe1BS1b58AccyAkwHB5x5glbDbairBSFZ42vIUgZ2w1H0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Vhqirkz5; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Vhqirkz5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6728AC2BD10; Wed, 3 Jul 2024 10:54:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1720004041; bh=Sum860Pf2oIZ/F4xNrN9xauCmYGYUGFfQdjE+mjiu80=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Vhqirkz5sY626wfU6sPVL9eF5VJc/OcXILZMnIrR5Z/SplVBZt1x7qRoZnnWsif4U C4LeLNnn0DRHvuHM/vdYyI/X6bJAMh1lT1LU5xljeyrQDRaEa85xLdVVBOEIS8S6PY 7IDDU0HRZ/LJwZcW5OPCst7orImJl0lwVPadwO/0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot , Eric Dumazet , Lorenzo Bianconi , David Ahern , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.4 105/189] ipv6: prevent possible NULL deref in fib6_nh_init() Date: Wed, 3 Jul 2024 12:39:26 +0200 Message-ID: <20240703102845.466456819@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240703102841.492044697@linuxfoundation.org> References: <20240703102841.492044697@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 2eab4543a2204092c3a7af81d7d6c506e59a03a6 ] syzbot reminds us that in6_dev_get() can return NULL. fib6_nh_init() ip6_validate_gw( &idev ) ip6_route_check_nh( idev ) *idev = in6_dev_get(dev); // can be NULL Oops: general protection fault, probably for non-canonical address 0xdffffc00000000bc: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x00000000000005e0-0x00000000000005e7] CPU: 0 PID: 11237 Comm: syz-executor.3 Not tainted 6.10.0-rc2-syzkaller-00249-gbe27b8965297 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:fib6_nh_init+0x640/0x2160 net/ipv6/route.c:3606 Code: 00 00 fc ff df 4c 8b 64 24 58 48 8b 44 24 28 4c 8b 74 24 30 48 89 c1 48 89 44 24 28 48 8d 98 e0 05 00 00 48 89 d8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 0f 85 b3 17 00 00 8b 1b 31 ff 89 de e8 b8 8b RSP: 0018:ffffc900032775a0 EFLAGS: 00010202 RAX: 00000000000000bc RBX: 00000000000005e0 RCX: 0000000000000000 RDX: 0000000000000010 RSI: ffffc90003277a54 RDI: ffff88802b3a08d8 RBP: ffffc900032778b0 R08: 00000000000002fc R09: 0000000000000000 R10: 00000000000002fc R11: 0000000000000000 R12: ffff88802b3a08b8 R13: 1ffff9200064eec8 R14: ffffc90003277a00 R15: dffffc0000000000 FS: 00007f940feb06c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000000245e8000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ip6_route_info_create+0x99e/0x12b0 net/ipv6/route.c:3809 ip6_route_add+0x28/0x160 net/ipv6/route.c:3853 ipv6_route_ioctl+0x588/0x870 net/ipv6/route.c:4483 inet6_ioctl+0x21a/0x280 net/ipv6/af_inet6.c:579 sock_do_ioctl+0x158/0x460 net/socket.c:1222 sock_ioctl+0x629/0x8e0 net/socket.c:1341 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f940f07cea9 Fixes: 428604fb118f ("ipv6: do not set routes if disable_ipv6 has been enabled") Reported-by: syzbot Signed-off-by: Eric Dumazet Acked-by: Lorenzo Bianconi Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20240614082002.26407-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv6/route.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 08cdb38d41d86..f2ffec3db5cfb 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -3506,7 +3506,7 @@ int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh, if (!dev) goto out; - if (idev->cnf.disable_ipv6) { + if (!idev || idev->cnf.disable_ipv6) { NL_SET_ERR_MSG(extack, "IPv6 is disabled on nexthop device"); err = -EACCES; goto out; -- 2.43.0