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 763068486 for ; Thu, 27 Oct 2022 16:59:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EB975C433D7; Thu, 27 Oct 2022 16:59:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666889962; bh=wtaCuprZStMmzN5w+ybxoB7+9PFyW1OW3UkTjKTCOuI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UZVXq4o1Fz2s1zKFj5RgmC9y9McGFnSQULtXw0dvr37QVUoUn3bn3Q6/Ys/8bi9PL xGoLiS3e3t5z1O3Iepkmf/bmRr74zsa1fDsQ4X8DVUvegM1BqYFNICzsCqOlWGZkcT tLn54kTDFAGYc8R4QW0qSMHERD4HgURhyXzbwG+A= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zhengchao Shao , Eric Dumazet , Paolo Abeni , Sasha Levin Subject: [PATCH 6.0 57/94] ip6mr: fix UAF issue in ip6mr_sk_done() when addrconf_init_net() failed Date: Thu, 27 Oct 2022 18:54:59 +0200 Message-Id: <20221027165059.476440847@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221027165057.208202132@linuxfoundation.org> References: <20221027165057.208202132@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Zhengchao Shao [ Upstream commit 1ca695207ed2271ecbf8ee6c641970f621c157cc ] If the initialization fails in calling addrconf_init_net(), devconf_all is the pointer that has been released. Then ip6mr_sk_done() is called to release the net, accessing devconf->mc_forwarding directly causes invalid pointer access. The process is as follows: setup_net() ops_init() addrconf_init_net() all = kmemdup(...) ---> alloc "all" ... net->ipv6.devconf_all = all; __addrconf_sysctl_register() ---> failed ... kfree(all); ---> ipv6.devconf_all invalid ... ops_exit_list() ... ip6mr_sk_done() devconf = net->ipv6.devconf_all; //devconf is invalid pointer if (!devconf || !atomic_read(&devconf->mc_forwarding)) The following is the Call Trace information: BUG: KASAN: use-after-free in ip6mr_sk_done+0x112/0x3a0 Read of size 4 at addr ffff888075508e88 by task ip/14554 Call Trace: dump_stack_lvl+0x8e/0xd1 print_report+0x155/0x454 kasan_report+0xba/0x1f0 kasan_check_range+0x35/0x1b0 ip6mr_sk_done+0x112/0x3a0 rawv6_close+0x48/0x70 inet_release+0x109/0x230 inet6_release+0x4c/0x70 sock_release+0x87/0x1b0 igmp6_net_exit+0x6b/0x170 ops_exit_list+0xb0/0x170 setup_net+0x7ac/0xbd0 copy_net_ns+0x2e6/0x6b0 create_new_namespaces+0x382/0xa50 unshare_nsproxy_namespaces+0xa6/0x1c0 ksys_unshare+0x3a4/0x7e0 __x64_sys_unshare+0x2d/0x40 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7f7963322547 Allocated by task 14554: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 __kasan_kmalloc+0xa1/0xb0 __kmalloc_node_track_caller+0x4a/0xb0 kmemdup+0x28/0x60 addrconf_init_net+0x1be/0x840 ops_init+0xa5/0x410 setup_net+0x5aa/0xbd0 copy_net_ns+0x2e6/0x6b0 create_new_namespaces+0x382/0xa50 unshare_nsproxy_namespaces+0xa6/0x1c0 ksys_unshare+0x3a4/0x7e0 __x64_sys_unshare+0x2d/0x40 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Freed by task 14554: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_save_free_info+0x2a/0x40 ____kasan_slab_free+0x155/0x1b0 slab_free_freelist_hook+0x11b/0x220 __kmem_cache_free+0xa4/0x360 addrconf_init_net+0x623/0x840 ops_init+0xa5/0x410 setup_net+0x5aa/0xbd0 copy_net_ns+0x2e6/0x6b0 create_new_namespaces+0x382/0xa50 unshare_nsproxy_namespaces+0xa6/0x1c0 ksys_unshare+0x3a4/0x7e0 __x64_sys_unshare+0x2d/0x40 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Fixes: 7d9b1b578d67 ("ip6mr: fix use-after-free in ip6mr_sk_done()") Signed-off-by: Zhengchao Shao Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20221017080331.16878-1-shaozhengchao@huawei.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- net/ipv6/addrconf.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 10ce86bf228e..d5967cba5b56 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -7214,9 +7214,11 @@ static int __net_init addrconf_init_net(struct net *net) __addrconf_sysctl_unregister(net, all, NETCONFA_IFINDEX_ALL); err_reg_all: kfree(dflt); + net->ipv6.devconf_dflt = NULL; #endif err_alloc_dflt: kfree(all); + net->ipv6.devconf_all = NULL; err_alloc_all: kfree(net->ipv6.inet6_addr_lst); err_alloc_addr: -- 2.35.1