[PATCH] stdlib: fix arc4random fallback to /dev/urandom (BZ 31612)
Adhemerval Zanella
adhemerval.zanella@linaro.org
Mon May 6 18:19:02 GMT 2024
The __getrandom_nocancel used by __arc4random_buf uses
INLINE_SYSCALL_CALL (which returns -1/errno) and the loop checks for
the return value instead of errno to fallback to /dev/urandom.
The malloc code now uses __getrandom_nocancel_nostatus, which uses
INTERNAL_SYSCALL_CALL, so there is no need to use the variant that does
not set errno (BZ#29624).
Checked on x86_64-linux-gnu.
---
stdlib/arc4random.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/stdlib/arc4random.c b/stdlib/arc4random.c
index 3ae8fc1302..7818cb9cf6 100644
--- a/stdlib/arc4random.c
+++ b/stdlib/arc4random.c
@@ -51,7 +51,7 @@ __arc4random_buf (void *p, size_t n)
n -= l;
continue; /* Interrupted by a signal; keep going. */
}
- else if (l == -ENOSYS)
+ else if (l < 0 && errno == ENOSYS)
break; /* No syscall, so fallback to /dev/urandom. */
arc4random_getrandom_failure ();
}
--
2.43.0
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