Messages in this thread Patch in this message | | | From | Arnd Bergmann <> | Subject | [PATCH] random: fix rdrand mix-in | Date | Tue, 17 Jul 2018 15:53:00 +0200 |
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The newly added arch_get_random_int() call was done incorrectly, using the output only if rdrand hardware was /not/ available. The compiler points out that the data is uninitialized in this case:
drivers/char/random.c: In function 'write_pool.constprop': drivers/char/random.c:1912:11: error: 't' may be used uninitialized in this function [-Werror=maybe-uninitialized]
This fixes the condition so we only use that data when it was valid.
Fixes: 349ddb707fb7 ("random: mix rdrand with entropy sent in from userspace") Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- drivers/char/random.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/char/random.c b/drivers/char/random.c index 283fe390e878..71660aef8c8c 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1907,7 +1907,7 @@ write_pool(struct entropy_store *r, const char __user *buffer, size_t count) return -EFAULT; for (b = bytes ; b > 0 ; b -= sizeof(__u32), i++) { - if (arch_get_random_int(&t)) + if (!arch_get_random_int(&t)) continue; buf[i] ^= t; } -- 2.9.0
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