============================= WARNING: suspicious RCU usage 5.12.0-rc4-syzkaller #0 Not tainted ----------------------------- kernel/sched/core.c:8294 Illegal context switch in RCU-bh read-side critical section! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by syz-executor.4/10630: #0: ffffffff8bfb7248 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8bfb7248 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x2e4/0x860 net/core/rtnetlink.c:5550 #1: ffffffff8a96aea0 (rcu_read_lock_bh){....}-{1:2}, at: addrconf_verify_rtnl+0x1b/0xcf0 net/ipv6/addrconf.c:4459 stack backtrace: CPU: 1 PID: 10630 Comm: syz-executor.4 Not tainted 5.12.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0xa5/0xe6 lib/dump_stack.c:120 ___might_sleep+0x229/0x2c0 kernel/sched/core.c:8294 might_alloc include/linux/sched/mm.h:197 [inline] slab_pre_alloc_hook mm/slab.h:497 [inline] slab_alloc_node mm/slub.c:2826 [inline] slab_alloc mm/slub.c:2915 [inline] kmem_cache_alloc_trace+0x263/0x2a0 mm/slub.c:2932 kmalloc include/linux/slab.h:554 [inline] kzalloc include/linux/slab.h:684 [inline] mld_add_delrec net/ipv6/mcast.c:725 [inline] igmp6_leave_group net/ipv6/mcast.c:2570 [inline] igmp6_group_dropped+0x3f9/0xcf0 net/ipv6/mcast.c:706 __ipv6_dev_mc_dec+0x19b/0x270 net/ipv6/mcast.c:953 addrconf_leave_solict net/ipv6/addrconf.c:2182 [inline] addrconf_leave_solict net/ipv6/addrconf.c:2174 [inline] __ipv6_ifa_notify+0x4de/0x910 net/ipv6/addrconf.c:6077 ipv6_ifa_notify net/ipv6/addrconf.c:6100 [inline] ipv6_del_addr+0x39d/0x8f0 net/ipv6/addrconf.c:1294 addrconf_verify_rtnl+0x8c8/0xcf0 net/ipv6/addrconf.c:4488 inet6_addr_modify net/ipv6/addrconf.c:4789 [inline] inet6_rtm_newaddr+0xda9/0x18c0 net/ipv6/addrconf.c:4876 rtnetlink_rcv_msg+0x32f/0x860 net/core/rtnetlink.c:5553 netlink_rcv_skb+0x118/0x370 net/netlink/af_netlink.c:2502 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline] netlink_unicast+0x42e/0x700 net/netlink/af_netlink.c:1338 netlink_sendmsg+0x70e/0xbe0 net/netlink/af_netlink.c:1927 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg+0xab/0xe0 net/socket.c:674 ____sys_sendmsg+0x5bf/0x7a0 net/socket.c:2350 ___sys_sendmsg+0xd3/0x150 net/socket.c:2404 __sys_sendmsg+0xb2/0x140 net/socket.c:2433 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665f9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f12c8b7f188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000056c158 RCX: 00000000004665f9 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000007 RBP: 00000000004bfce1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c158 R13: 00007fff20f320af R14: 00007f12c8b7f300 R15: 0000000000022000 BUG: sleeping function called from invalid context at include/linux/sched/mm.h:197 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 10630, name: syz-executor.4 2 locks held by syz-executor.4/10630: #0: ffffffff8bfb7248 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8bfb7248 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x2e4/0x860 net/core/rtnetlink.c:5550 #1: ffffffff8a96aea0 (rcu_read_lock_bh){....}-{1:2}, at: addrconf_verify_rtnl+0x1b/0xcf0 net/ipv6/addrconf.c:4459 Preemption disabled at: [] local_bh_disable include/linux/bottom_half.h:19 [inline] [] rcu_read_lock_bh include/linux/rcupdate.h:727 [inline] [] addrconf_verify_rtnl+0x2c/0xcf0 net/ipv6/addrconf.c:4461 CPU: 1 PID: 10630 Comm: syz-executor.4 Not tainted 5.12.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0xa5/0xe6 lib/dump_stack.c:120 ___might_sleep.cold+0x1f1/0x237 kernel/sched/core.c:8328 might_alloc include/linux/sched/mm.h:197 [inline] slab_pre_alloc_hook mm/slab.h:497 [inline] slab_alloc_node mm/slub.c:2826 [inline] slab_alloc mm/slub.c:2915 [inline] kmem_cache_alloc_trace+0x263/0x2a0 mm/slub.c:2932 kmalloc include/linux/slab.h:554 [inline] kzalloc include/linux/slab.h:684 [inline] mld_add_delrec net/ipv6/mcast.c:725 [inline] igmp6_leave_group net/ipv6/mcast.c:2570 [inline] igmp6_group_dropped+0x3f9/0xcf0 net/ipv6/mcast.c:706 __ipv6_dev_mc_dec+0x19b/0x270 net/ipv6/mcast.c:953 addrconf_leave_solict net/ipv6/addrconf.c:2182 [inline] addrconf_leave_solict net/ipv6/addrconf.c:2174 [inline] __ipv6_ifa_notify+0x4de/0x910 net/ipv6/addrconf.c:6077 ipv6_ifa_notify net/ipv6/addrconf.c:6100 [inline] ipv6_del_addr+0x39d/0x8f0 net/ipv6/addrconf.c:1294 addrconf_verify_rtnl+0x8c8/0xcf0 net/ipv6/addrconf.c:4488 inet6_addr_modify net/ipv6/addrconf.c:4789 [inline] inet6_rtm_newaddr+0xda9/0x18c0 net/ipv6/addrconf.c:4876 rtnetlink_rcv_msg+0x32f/0x860 net/core/rtnetlink.c:5553 netlink_rcv_skb+0x118/0x370 net/netlink/af_netlink.c:2502 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline] netlink_unicast+0x42e/0x700 net/netlink/af_netlink.c:1338 netlink_sendmsg+0x70e/0xbe0 net/netlink/af_netlink.c:1927 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg+0xab/0xe0 net/socket.c:674 ____sys_sendmsg+0x5bf/0x7a0 net/socket.c:2350 ___sys_sendmsg+0xd3/0x150 net/socket.c:2404 __sys_sendmsg+0xb2/0x140 net/socket.c:2433 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665f9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f12c8b7f188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000056c158 RCX: 00000000004665f9 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000007 RBP: 00000000004bfce1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c158 R13: 00007fff20f320af R14: 00007f12c8b7f300 R15: 0000000000022000