stable inclusion
from stable-v5.10.119
commit bb63851c25576e83cabe2d26c6548f3d5085d0e7
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5L6BB

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=bb63851c25576e83cabe2d26c6548f3d5085d0e7

--------------------------------

commit 7b5164fb upstream.

This buffer may contain entropic data that shouldn't stick around longer
than needed, so zero out the temporary buffer at the end of write_pool().
Reviewed-by: NDominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: NJann Horn <jannh@google.com>
Reviewed-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NJason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>