This is a note to let you know that I've just added the patch titled
random: Add a urandom_read_nowait() for random APIs that don't warn
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
random-add-a-urandom_read_nowait-for-random-apis-that-don-t-warn.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Fri Jun 17 08:58:56 AM CEST 2022
From: Andy Lutomirski <luto@xxxxxxxxxx>
Date: Mon, 23 Dec 2019 00:20:45 -0800
Subject: random: Add a urandom_read_nowait() for random APIs that don't warn
From: Andy Lutomirski <luto@xxxxxxxxxx>
commit c6f1deb158789abba02a7eba600747843eeb3a57 upstream.
/dev/random and getrandom() never warn. Split the meat of
urandom_read() into urandom_read_nowarn() and leave the warning code
in urandom_read().
This has no effect on kernel behavior, but it makes subsequent
patches more straightforward. It also makes the fact that
getrandom() never warns more obvious.
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
Link: https://lore.kernel.org/r/c87ab200588de746431d9f916501ef11e5242b13.1577088521.git.luto@xxxxxxxxxx
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/char/random.c | 21 +++++++++++++++------
1 file changed, 15 insertions(+), 6 deletions(-)
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -2025,11 +2025,22 @@ random_read(struct file *file, char __us
}
static ssize_t
+urandom_read_nowarn(struct file *file, char __user *buf, size_t nbytes,
+ loff_t *ppos)
+{
+ int ret;
+
+ nbytes = min_t(size_t, nbytes, INT_MAX >> (ENTROPY_SHIFT + 3));
+ ret = extract_crng_user(buf, nbytes);
+ trace_urandom_read(8 * nbytes, 0, ENTROPY_BITS(&input_pool));
+ return ret;
+}
+
+static ssize_t
urandom_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
{
unsigned long flags;
static int maxwarn = 10;
- int ret;
if (!crng_ready() && maxwarn > 0) {
maxwarn--;
@@ -2041,10 +2052,8 @@ urandom_read(struct file *file, char __u
crng_init_cnt = 0;
spin_unlock_irqrestore(&primary_crng.lock, flags);
}
- nbytes = min_t(size_t, nbytes, INT_MAX >> (ENTROPY_SHIFT + 3));
- ret = extract_crng_user(buf, nbytes);
- trace_urandom_read(8 * nbytes, 0, ENTROPY_BITS(&input_pool));
- return ret;
+
+ return urandom_read_nowarn(file, buf, nbytes, ppos);
}
static __poll_t
@@ -2204,7 +2213,7 @@ SYSCALL_DEFINE3(getrandom, char __user *
if (unlikely(ret))
return ret;
}
- return urandom_read(NULL, buf, count, NULL);
+ return urandom_read_nowarn(NULL, buf, count, NULL);
}
/********************************************************************
Patches currently in stable-queue which might be from luto@xxxxxxxxxx are
queue-4.19/random-remove-kernel.random.read_wakeup_threshold.patch
queue-4.19/random-initialize-chacha20-constants-with-correct-endianness.patch
queue-4.19/random-make-dev-random-be-almost-like-dev-urandom.patch
queue-4.19/random-remove-batched-entropy-locking.patch
queue-4.19/random-remove-the-blocking-pool.patch
queue-4.19/random-ignore-grnd_random-in-getentropy-2.patch
queue-4.19/random-delete-code-to-pull-data-into-pools.patch
queue-4.19/random-don-t-wake-crng_init_wait-when-crng_init-1.patch
queue-4.19/random-add-a-urandom_read_nowait-for-random-apis-that-don-t-warn.patch
queue-4.19/random-remove-dead-code-left-over-from-blocking-pool.patch
queue-4.19/random-add-grnd_insecure-to-return-best-effort-non-cryptographic-bytes.patch
