| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.10 36/54] random: clamp credited irq bits to maximum mixed | Date | Thu, 13 Oct 2022 19:52:30 +0200 |
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From: Jason A. Donenfeld <Jason@zx2c4.com>
commit e78a802a7b4febf53f2a92842f494b01062d85a8 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: e3e33fc2ea7f ("random: do not use input pool from hard IRQs") Cc: stable@vger.kernel.org Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/char/random.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -981,7 +981,7 @@ static void mix_interrupt_randomness(str 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)); }
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