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| author | Theodore Ts'o <tytso@mit.edu> | 2016-06-13 10:10:51 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2016-06-13 11:54:26 -0400 |
| commit | 9b4d008787f864f17d008c9c15bbe8a0f7e2fc24 (patch) | |
| tree | 95ed8d9865986a90511e583f7f163434e09860d2 /drivers/char/random.c | |
| parent | 3371f3da08cff4b75c1f2dce742d460539d6566d (diff) | |
| download | linux-stable-9b4d008787f864f17d008c9c15bbe8a0f7e2fc24.tar.gz linux-stable-9b4d008787f864f17d008c9c15bbe8a0f7e2fc24.tar.bz2 linux-stable-9b4d008787f864f17d008c9c15bbe8a0f7e2fc24.zip | |
random: print a warning for the first ten uninitialized random users
Since systemd is consistently using /dev/urandom before it is
initialized, we can't see the other potentially dangerous users of
/dev/urandom immediately after boot. So print the first ten such
complaints instead.
Cc: stable@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'drivers/char/random.c')
| -rw-r--r-- | drivers/char/random.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index 4e2627a8d226..d057438266bb 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1458,12 +1458,16 @@ random_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos) static ssize_t urandom_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos) { + static int maxwarn = 10; int ret; - if (unlikely(nonblocking_pool.initialized == 0)) - printk_once(KERN_NOTICE "random: %s urandom read " - "with %d bits of entropy available\n", - current->comm, nonblocking_pool.entropy_total); + if (unlikely(nonblocking_pool.initialized == 0) && + maxwarn > 0) { + maxwarn--; + printk(KERN_NOTICE "random: %s: uninitialized urandom read " + "(%zd bytes read, %d bits of entropy available)\n", + current->comm, nbytes, nonblocking_pool.entropy_total); + } nbytes = min_t(size_t, nbytes, INT_MAX >> (ENTROPY_SHIFT + 3)); ret = extract_entropy_user(&nonblocking_pool, buf, nbytes); |