KCSAN: data-race in _extract_crng / crng

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in _extract_crng / crng_reseed (2) kernel	6				1	2034d	2034d	0/29	auto-closed as invalid on 2021/02/24 01:37
upstream	KCSAN: data-race in _extract_crng / crng_reseed kernel	6				2	2181d	2196d	0/29	auto-closed as invalid on 2020/09/29 18:37

================================================================== BUG: KCSAN: data-race in _extract_crng / crng_reseed write to 0xffffffff841ab058 of 8 bytes by task 1817 on cpu 1: crng_reseed+0x404/0x6a0 drivers/char/random.c:965 _extract_crng+0xcc/0x2d0 drivers/char/random.c:996 crng_reseed+0x69/0x6a0 drivers/char/random.c:952 _extract_crng+0xcc/0x2d0 drivers/char/random.c:996 extract_crng drivers/char/random.c:1016 [inline] get_random_u64+0xf8/0x1f0 drivers/char/random.c:2178 get_random_long include/linux/random.h:61 [inline] get_random_canary include/linux/random.h:83 [inline] dup_task_struct+0x3db/0x630 kernel/fork.c:923 copy_process+0x3ff/0x2f70 kernel/fork.c:1952 kernel_clone+0x14b/0x680 kernel/fork.c:2509 __do_sys_clone kernel/fork.c:2626 [inline] __se_sys_clone kernel/fork.c:2610 [inline] __x64_sys_clone+0xb4/0xe0 kernel/fork.c:2610 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffffffff841ab058 of 8 bytes by task 1818 on cpu 0: _extract_crng+0x47/0x2d0 drivers/char/random.c:994 crng_reseed+0x69/0x6a0 drivers/char/random.c:952 _extract_crng+0xcc/0x2d0 drivers/char/random.c:996 extract_crng drivers/char/random.c:1016 [inline] get_random_u64+0xf8/0x1f0 drivers/char/random.c:2178 get_random_long include/linux/random.h:61 [inline] get_random_canary include/linux/random.h:83 [inline] dup_task_struct+0x3db/0x630 kernel/fork.c:923 copy_process+0x3ff/0x2f70 kernel/fork.c:1952 kernel_clone+0x14b/0x680 kernel/fork.c:2509 __do_sys_clone kernel/fork.c:2626 [inline] __se_sys_clone kernel/fork.c:2610 [inline] __x64_sys_clone+0xb4/0xe0 kernel/fork.c:2610 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x0000000100000074 -> 0x0000000100007656 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 1818 Comm: syz-executor.3 Not tainted 5.14.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================