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 D57991DA4D; Tue, 16 Jul 2024 15:46:08 +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=1721144768; cv=none; b=AeF0BI9uVZ67VfAcpsX9SRLUeDcMBlH9UttqfzFPdGaMQPeY0zCES7QuuXHgjhdNxCODf5PQXoAyElBT4meQGH58BgsMiQIYhKtF/IYgV1ystpaEr6PYuTfDcIOLN+zkJyzeBrH+ZPLmStWJqELDhMXqwxjQ79Z44sTfCJC8qX0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721144768; c=relaxed/simple; bh=p/GfxnfRBeCiFFNvkhki55KNiPz+FPWMAq9lDvZFS/4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Sv4hUoUpKK+Lw+dSD5ZXfW7A5gLMxIBZeUmlJRgfTFJrJtWwD4ezzNoReEnPvrrwZ9S4eGbGYEMPPrvaxkwgJI9te1YmlS9UkN+8gHqdHHqOuwpHg9HOilPj3jW59CKlCIxSIzeYDXK02PbekefQRQAys+MQcpeIq4v2ACKpDWk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Nvw+5Fhm; 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="Nvw+5Fhm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 50AECC116B1; Tue, 16 Jul 2024 15:46:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1721144768; bh=p/GfxnfRBeCiFFNvkhki55KNiPz+FPWMAq9lDvZFS/4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Nvw+5FhmilIwPWSJeIWx3wH9egxr/ftVpUfDer7FC2EA83RiuC1kg1+YguCg3zfBa I++Eq4EKR5jU6JnefP3/j+8O94wC2vRczSk1JngSCJdlWEpK6S/VPA4QakEPnfAvI2 6VqUFQnSY/ATifw3VB6vFj9G8ENJaRnsAaNeLRhM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Gerald Yang , Chengen Du , Paolo Abeni , Sasha Levin Subject: [PATCH 5.10 069/108] net/sched: Fix UAF when resolving a clash Date: Tue, 16 Jul 2024 17:31:24 +0200 Message-ID: <20240716152748.631729275@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240716152745.988603303@linuxfoundation.org> References: <20240716152745.988603303@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 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chengen Du [ Upstream commit 26488172b0292bed837b95a006a3f3431d1898c3 ] KASAN reports the following UAF: BUG: KASAN: slab-use-after-free in tcf_ct_flow_table_process_conn+0x12b/0x380 [act_ct] Read of size 1 at addr ffff888c07603600 by task handler130/6469 Call Trace: dump_stack_lvl+0x48/0x70 print_address_description.constprop.0+0x33/0x3d0 print_report+0xc0/0x2b0 kasan_report+0xd0/0x120 __asan_load1+0x6c/0x80 tcf_ct_flow_table_process_conn+0x12b/0x380 [act_ct] tcf_ct_act+0x886/0x1350 [act_ct] tcf_action_exec+0xf8/0x1f0 fl_classify+0x355/0x360 [cls_flower] __tcf_classify+0x1fd/0x330 tcf_classify+0x21c/0x3c0 sch_handle_ingress.constprop.0+0x2c5/0x500 __netif_receive_skb_core.constprop.0+0xb25/0x1510 __netif_receive_skb_list_core+0x220/0x4c0 netif_receive_skb_list_internal+0x446/0x620 napi_complete_done+0x157/0x3d0 gro_cell_poll+0xcf/0x100 __napi_poll+0x65/0x310 net_rx_action+0x30c/0x5c0 __do_softirq+0x14f/0x491 __irq_exit_rcu+0x82/0xc0 irq_exit_rcu+0xe/0x20 common_interrupt+0xa1/0xb0 asm_common_interrupt+0x27/0x40 Allocated by task 6469: kasan_save_stack+0x38/0x70 kasan_set_track+0x25/0x40 kasan_save_alloc_info+0x1e/0x40 __kasan_krealloc+0x133/0x190 krealloc+0xaa/0x130 nf_ct_ext_add+0xed/0x230 [nf_conntrack] tcf_ct_act+0x1095/0x1350 [act_ct] tcf_action_exec+0xf8/0x1f0 fl_classify+0x355/0x360 [cls_flower] __tcf_classify+0x1fd/0x330 tcf_classify+0x21c/0x3c0 sch_handle_ingress.constprop.0+0x2c5/0x500 __netif_receive_skb_core.constprop.0+0xb25/0x1510 __netif_receive_skb_list_core+0x220/0x4c0 netif_receive_skb_list_internal+0x446/0x620 napi_complete_done+0x157/0x3d0 gro_cell_poll+0xcf/0x100 __napi_poll+0x65/0x310 net_rx_action+0x30c/0x5c0 __do_softirq+0x14f/0x491 Freed by task 6469: kasan_save_stack+0x38/0x70 kasan_set_track+0x25/0x40 kasan_save_free_info+0x2b/0x60 ____kasan_slab_free+0x180/0x1f0 __kasan_slab_free+0x12/0x30 slab_free_freelist_hook+0xd2/0x1a0 __kmem_cache_free+0x1a2/0x2f0 kfree+0x78/0x120 nf_conntrack_free+0x74/0x130 [nf_conntrack] nf_ct_destroy+0xb2/0x140 [nf_conntrack] __nf_ct_resolve_clash+0x529/0x5d0 [nf_conntrack] nf_ct_resolve_clash+0xf6/0x490 [nf_conntrack] __nf_conntrack_confirm+0x2c6/0x770 [nf_conntrack] tcf_ct_act+0x12ad/0x1350 [act_ct] tcf_action_exec+0xf8/0x1f0 fl_classify+0x355/0x360 [cls_flower] __tcf_classify+0x1fd/0x330 tcf_classify+0x21c/0x3c0 sch_handle_ingress.constprop.0+0x2c5/0x500 __netif_receive_skb_core.constprop.0+0xb25/0x1510 __netif_receive_skb_list_core+0x220/0x4c0 netif_receive_skb_list_internal+0x446/0x620 napi_complete_done+0x157/0x3d0 gro_cell_poll+0xcf/0x100 __napi_poll+0x65/0x310 net_rx_action+0x30c/0x5c0 __do_softirq+0x14f/0x491 The ct may be dropped if a clash has been resolved but is still passed to the tcf_ct_flow_table_process_conn function for further usage. This issue can be fixed by retrieving ct from skb again after confirming conntrack. Fixes: 0cc254e5aa37 ("net/sched: act_ct: Offload connections with commit action") Co-developed-by: Gerald Yang Signed-off-by: Gerald Yang Signed-off-by: Chengen Du Link: https://patch.msgid.link/20240710053747.13223-1-chengen.du@canonical.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- net/sched/act_ct.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/net/sched/act_ct.c b/net/sched/act_ct.c index c6d6a6fe9602b..a59a8ad387211 100644 --- a/net/sched/act_ct.c +++ b/net/sched/act_ct.c @@ -1038,6 +1038,14 @@ static int tcf_ct_act(struct sk_buff *skb, const struct tc_action *a, */ if (nf_conntrack_confirm(skb) != NF_ACCEPT) goto drop; + + /* The ct may be dropped if a clash has been resolved, + * so it's necessary to retrieve it from skb again to + * prevent UAF. + */ + ct = nf_ct_get(skb, &ctinfo); + if (!ct) + skip_add = true; } if (!skip_add) -- 2.43.0