ipv6: use GFP_ATOMIC in rt6_probe()
syzbot reminded me that rt6_probe() can run from atomic contexts. stack backtrace: CPU: 1 PID: 7461 Comm: syz-executor.2 Not tainted 5.16.0-rc4-next-20211210-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_usage_bug kernel/locking/lockdep.c:203 [inline] valid_state kernel/locking/lockdep.c:3945 [inline] mark_lock_irq kernel/locking/lockdep.c:4148 [inline] mark_lock.cold+0x61/0x8e kernel/locking/lockdep.c:4605 mark_usage kernel/locking/lockdep.c:4500 [inline] __lock_acquire+0x11d5/0x54a0 kernel/locking/lockdep.c:4981 lock_acquire kernel/locking/lockdep.c:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 __fs_reclaim_acquire mm/page_alloc.c:4550 [inline] fs_reclaim_acquire+0x115/0x160 mm/page_alloc.c:4564 might_alloc include/linux/sched/mm.h:253 [inline] slab_pre_alloc_hook mm/slab.h:739 [inline] slab_alloc_node mm/slub.c:3145 [inline] slab_alloc mm/slub.c:3239 [inline] kmem_cache_alloc_trace+0x3b/0x2c0 mm/slub.c:3256 kmalloc include/linux/slab.h:581 [inline] kzalloc include/linux/slab.h:715 [inline] ref_tracker_alloc+0xe1/0x430 lib/ref_tracker.c:74 netdev_tracker_alloc include/linux/netdevice.h:3860 [inline] dev_hold_track include/linux/netdevice.h:3877 [inline] rt6_probe net/ipv6/route.c:661 [inline] find_match.part.0+0xac9/0xd00 net/ipv6/route.c:752 find_match net/ipv6/route.c:825 [inline] __find_rr_leaf+0x17f/0xd20 net/ipv6/route.c:826 find_rr_leaf net/ipv6/route.c:847 [inline] rt6_select net/ipv6/route.c:891 [inline] fib6_table_lookup+0x649/0xa20 net/ipv6/route.c:2185 ip6_pol_route+0x1c5/0x11e0 net/ipv6/route.c:2221 pol_lookup_func include/net/ip6_fib.h:580 [inline] fib6_rule_lookup+0x52a/0x6f0 net/ipv6/fib6_rules.c:120 ip6_route_output_flags_noref+0x2e2/0x380 net/ipv6/route.c:2629 ip6_route_output_flags+0x72/0x320 net/ipv6/route.c:2642 ip6_route_output include/net/ip6_route.h:98 [inline] ip6_dst_lookup_tail+0x5ab/0x1620 net/ipv6/ip6_output.c:1070 ip6_dst_lookup_flow+0x8c/0x1d0 net/ipv6/ip6_output.c:1200 geneve_get_v6_dst+0x46f/0x9a0 drivers/net/geneve.c:858 geneve6_xmit_skb drivers/net/geneve.c:991 [inline] geneve_xmit+0x520/0x3530 drivers/net/geneve.c:1074 __netdev_start_xmit include/linux/netdevice.h:4685 [inline] netdev_start_xmit include/linux/netdevice.h:4699 [inline] xmit_one net/core/dev.c:3473 [inline] dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3489 __dev_queue_xmit+0x2983/0x3640 net/core/dev.c:4112 neigh_resolve_output net/core/neighbour.c:1522 [inline] neigh_resolve_output+0x50e/0x820 net/core/neighbour.c:1502 neigh_output include/net/neighbour.h:541 [inline] ip6_finish_output2+0x56e/0x14f0 net/ipv6/ip6_output.c:126 __ip6_finish_output net/ipv6/ip6_output.c:191 [inline] __ip6_finish_output+0x61e/0xe80 net/ipv6/ip6_output.c:170 ip6_finish_output+0x32/0x200 net/ipv6/ip6_output.c:201 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x1e4/0x530 net/ipv6/ip6_output.c:224 dst_output include/net/dst.h:451 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ndisc_send_skb+0xa99/0x17f0 net/ipv6/ndisc.c:508 ndisc_send_rs+0x12e/0x6f0 net/ipv6/ndisc.c:702 addrconf_rs_timer+0x3f2/0x820 net/ipv6/addrconf.c:3898 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 </IRQ> Fixes: fb67510b ("ipv6: add net device refcount tracker to rt6_probe_deferred()") Signed-off-by:Eric Dumazet <edumazet@google.com> Reported-by:
Please register or sign in to comment