Messages in this thread | | | Subject | Re: [BUG] net: xfrm: Two possible sleep-in-atomic-context bugs | From | Jia-Ju Bai <> | Date | Fri, 10 Aug 2018 15:30:40 +0800 |
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Thanks for your reply :)
On 2018/8/10 13:36, Steffen Klassert wrote: > On Fri, Aug 10, 2018 at 10:02:42AM +0800, bai wrote: >> 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 > igmp6_send calls sock_alloc_send_skb with 'noblock = 1', > this means that sock_wait_for_wmem is not executed in > sock_alloc_send_pskb. > >> 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 > ip6_forward calls pneigh_lookup with 'creat = 0', > this means that pneigh_lookup does not do the kmalloc. > >> ./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. > Both codepaths are ok, maybe you should fix your tool ;-)
It seems that the path condition checking in my tool needs to be improved. I will do it, thanks :)
Best wishes, Jia-Ju Bai
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