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BUG: KCSAN: data-race in yama_ptracer_del / yama_ptracer_del

read to 0xffff88809eaf75d0 of 1 bytes by interrupt on cpu 0:
 yama_ptracer_del+0xd6/0x1a0 security/yama/yama_lsm.c:187
 yama_task_free+0x22/0x30 security/yama/yama_lsm.c:207
 security_task_free+0x43/0xa0 security/security.c:1518
 __put_task_struct+0xcd/0x360 kernel/fork.c:745
 put_task_struct include/linux/sched/task.h:122 [inline]
 delayed_put_task_struct+0x1a5/0x1d0 kernel/exit.c:182
 __rcu_reclaim kernel/rcu/rcu.h:222 [inline]
 rcu_do_batch+0x256/0x5b0 kernel/rcu/tree.c:2183
 rcu_core+0x365/0x4c0 kernel/rcu/tree.c:2408
 rcu_core_si+0x12/0x20 kernel/rcu/tree.c:2417
 __do_softirq+0x115/0x33f kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0xbb/0xe0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0xe6/0x280 arch/x86/kernel/apic/apic.c:1137
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline]
 kcsan_setup_watchpoint+0x1d4/0x460 kernel/kcsan/core.c:429
 check_access kernel/kcsan/core.c:459 [inline]
 __tsan_read8+0xc6/0x100 kernel/kcsan/core.c:589
 find_inode_bit.isra.0+0x2cf/0x300 fs/ext4/ialloc.c:719
 __ext4_new_inode+0xd45/0x2f10 fs/ext4/ialloc.c:909
 ext4_symlink+0x31c/0x9b0 fs/ext4/namei.c:3275
 vfs_symlink fs/namei.c:4131 [inline]
 vfs_symlink+0x218/0x310 fs/namei.c:4117
 do_symlinkat+0x1a5/0x1e0 fs/namei.c:4158
 __do_sys_symlink fs/namei.c:4177 [inline]
 __se_sys_symlink fs/namei.c:4175 [inline]
 __x64_sys_symlink+0x3f/0x50 fs/namei.c:4175
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff88809eaf75d0 of 1 bytes by interrupt on cpu 1:
 yama_ptracer_del+0x119/0x1a0 security/yama/yama_lsm.c:191
 yama_task_free+0x22/0x30 security/yama/yama_lsm.c:207
 security_task_free+0x43/0xa0 security/security.c:1518
 __put_task_struct+0xcd/0x360 kernel/fork.c:745
 put_task_struct include/linux/sched/task.h:122 [inline]
 delayed_put_task_struct+0x1a5/0x1d0 kernel/exit.c:182
 __rcu_reclaim kernel/rcu/rcu.h:222 [inline]
 rcu_do_batch+0x256/0x5b0 kernel/rcu/tree.c:2183
 rcu_core+0x365/0x4c0 kernel/rcu/tree.c:2408
 rcu_core_si+0x12/0x20 kernel/rcu/tree.c:2417
 __do_softirq+0x115/0x33f kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0xbb/0xe0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0xe6/0x280 arch/x86/kernel/apic/apic.c:1137
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline]
 kcsan_setup_watchpoint+0x1d4/0x460 kernel/kcsan/core.c:429
 check_access kernel/kcsan/core.c:459 [inline]
 __tsan_read8+0xc6/0x100 kernel/kcsan/core.c:589
 batadv_nc_purge_paths+0x83/0x260 net/batman-adv/network-coding.c:437
 batadv_nc_worker+0x1b3/0x390 net/batman-adv/network-coding.c:721
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2264
 worker_thread+0xa0/0x800 kernel/workqueue.c:2410
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 23501 Comm: kworker/u4:5 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_nc_worker
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