lkml.org 
[lkml]   [2016]   [Nov]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Date
    Subject[PATCH 3.16 010/346] random: print a warning for the first ten uninitialized random users
    3.16.39-rc1 review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Theodore Ts'o <tytso@mit.edu>

    commit 9b4d008787f864f17d008c9c15bbe8a0f7e2fc24 upstream.

    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.

    Signed-off-by: Theodore Ts'o <tytso@mit.edu>
    Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
    ---
    drivers/char/random.c | 12 ++++++++----
    1 file changed, 8 insertions(+), 4 deletions(-)

    --- a/drivers/char/random.c
    +++ b/drivers/char/random.c
    @@ -1379,12 +1379,16 @@ random_read(struct file *file, char __us
    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);
    \
     
     \ /
      Last update: 2016-11-14 05:04    [W:3.724 / U:0.048 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site