TITLE: WARNING: locking bug in do_ipv6_setsockopt
TYPE: LOCKDEP

[  513.624689][ T4448] =============================
[  513.625024][ T4448] [ BUG: Invalid wait context ]
[  513.625454][ T4448] 5.9.0-12994-gf9893351acae #15 Not tainted
[  513.625876][ T4448] -----------------------------
[  513.626258][ T4448] syz-executor.0/4448 is trying to lock:
[  513.626811][ T4448] ffff00004a747498 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0x108/0x1b0
[  513.628246][ T4448] other info that might help us debug this:
[  513.628677][ T4448] context-{4:4}
[  513.629067][ T4448] 1 lock held by syz-executor.0/4448:
[  513.629453][ T4448]  #0: ffffa00019769560 (rcu_read_lock){....}-{1:2}, at: count_memcg_event_mm+0x24/0x2f0
[  513.630554][ T4448] stack backtrace:
[  513.631277][ T4448] CPU: 0 PID: 4448 Comm: syz-executor.0 Not tainted 5.9.0-12994-gf9893351acae #15
[  513.631738][ T4448] Hardware name: linux,dummy-virt (DT)
[  513.632435][ T4448] Call trace:
[  513.632830][ T4448]  dump_backtrace+0x0/0x4d0
[  513.633216][ T4448]  show_stack+0x2c/0x80
[  513.633605][ T4448]  dump_stack+0x1b0/0x254
[  513.633979][ T4448]  __lock_acquire+0x1a04/0x4930
[  513.634359][ T4448]  lock_acquire+0x278/0xb88
[  513.634769][ T4448]  __might_fault+0x138/0x1b0
[  513.635149][ T4448]  do_ipv6_setsockopt.isra.0+0x4a8/0x4738
[  513.635538][ T4448]  ipv6_setsockopt+0x124/0x408
[  513.635909][ T4448]  tcp_setsockopt+0x120/0x2548
[  513.636279][ T4448]  sock_common_setsockopt+0xa8/0xe0
[  513.636670][ T4448]  __sys_setsockopt+0x1f8/0x470
[  513.637057][ T4448]  __arm64_sys_setsockopt+0xa8/0x108
[  513.637464][ T4448]  el0_svc_common.constprop.0+0x158/0x530
[  513.637904][ T4448]  do_el0_svc+0x58/0x148
[  513.638295][ T4448]  el0_sync_handler+0x1f4/0x200
[  513.638674][ T4448]  el0_sync+0x174/0x180
