Commit 5bba83eb authored by Jason A. Donenfeld's avatar Jason A. Donenfeld Committed by Jialin Zhang
Browse files

random: clamp credited irq bits to maximum mixed 

stable inclusion
from stable-v5.10.148
commit 011399a3f926bcc8175610cbcb8981d512b11a17
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6D0WL

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=011399a3f926bcc8175610cbcb8981d512b11a17



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

commit e78a802a upstream.

Since the most that's mixed into the pool is sizeof(long)*2, don't
credit more than that many bytes of entropy.

Fixes: e3e33fc2 ("random: do not use input pool from hard IRQs")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarJason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
Reviewed-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent 8852b6ca

drivers/char/random.c

+1 −1
Original line number Diff line number Diff line
@@ -981,7 +981,7 @@ static void mix_interrupt_randomness(struct work_struct *work) 
	local_irq_enable();



	mix_pool_bytes(pool, sizeof(pool));

	credit_init_bits(max(1u, (count & U16_MAX) / 64));

	credit_init_bits(clamp_t(unsigned int, (count & U16_MAX) / 64, 1, sizeof(pool) * 8));



	memzero_explicit(pool, sizeof(pool));

}