Evolution-X-Devices/kernel_xiaomi_sm8350
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

random: zero buffer after reading entropy from userspace

Browse Source 
commit 7b5164fb1279bf0251371848e40bae646b59b3a8 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: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Jann Horn <jannh@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jason A. Donenfeld
2022-02-09 18:42:13 +01:00
committed by Greg Kroah-Hartman
parent 21da00f8cb
commit b1d5611381
1 changed files with 8 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
drivers/char/random.c
View File

@@ -1334,19 +1334,24 @@ static __poll_t random_poll(struct file *file, poll_table *wait)
static int write_pool(const char __user *ubuf, size_t count)
{
size_t len;
int ret = 0;
u8 block[BLAKE2S_BLOCK_SIZE];
while (count) {
len = min(count, sizeof(block));
if (copy_from_user(block, ubuf, len))
return -EFAULT;
if (copy_from_user(block, ubuf, len)) {
ret = -EFAULT;
goto out;
}
count -= len;
ubuf += len;
mix_pool_bytes(block, len);
cond_resched();
}
return 0;
out:
memzero_explicit(block, sizeof(block));
return ret;
}
static ssize_t random_write(struct file *file, const char __user *buffer,