From mboxrd@z Thu Jan 1 00:00:00 1970 From: bai Subject: [BUG] net: xfrm: Two possible sleep-in-atomic-context bugs Date: Fri, 10 Aug 2018 10:02:42 +0800 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: steffen.klassert@secunet.com, herbert@gondor.apana.org.au, davem@davemloft.net Return-path: Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org The code may sleep in interrupt handler. xfrm_trans_reinject() is an interrupt handler set in tasklet_init(). The function call paths (from bottom to top) in Linux-4.16 are: [FUNC] schedule_timeout net/core/sock.c, 2044: schedule_timeout in sock_wait_for_wmem net/core/sock.c, 2083: sock_wait_for_wmem in sock_alloc_send_pskb net/core/sock.c, 2102: sock_alloc_send_pskb in sock_alloc_send_skb net/ipv6/mcast.c, 1989: sock_alloc_send_skb in igmp6_send net/ipv6/mcast.c, 2391: igmp6_send in igmp6_join_group net/ipv6/mcast.c, 670: igmp6_join_group in igmp6_group_added net/ipv6/mcast.c, 914: igmp6_group_added in ipv6_dev_mc_inc net/ipv6/ndisc.c, 379: ipv6_dev_mc_inc in pndisc_constructor net/core/neighbour.c, 640: [FUNC_PTR]pndisc_constructor in pneigh_lookup net/ipv6/ip6_output.c, 483: pneigh_lookup in ip6_forward ./include/net/dst.h, 449: [FUNC_PTR]ip6_forward in dst_input net/ipv6/ip6_input.c, 71: dst_input in ip6_rcv_finish net/xfrm/xfrm_input.c, 511: [FUNC_PTR]ip6_rcv_finish in xfrm_trans_reinject [FUNC] kmalloc(GFP_KERNEL) net/core/neighbour.c, 630: kmalloc in pneigh_lookup net/ipv6/ip6_output.c, 483: pneigh_lookup in ip6_forward ./include/net/dst.h, 449: [FUNC_PTR]ip6_forward in dst_input net/ipv6/ip6_input.c, 71: dst_input in ip6_rcv_finish net/xfrm/xfrm_input.c, 511: [FUNC_PTR]ip6_rcv_finish in xfrm_trans_reinject Note that [FUNC_PTR] means a function pointer call is used. I do not find a good way to fix them, so I only report. These possible bugs are found by my static analysis tool (DSAC) and checked by my code review. Best wishes, Jia-Ju Bai