tree 5aaf1ca2800525fb4dfefd1790aa29213e57149b
parent 910d84009977441fcb5661683528f88ed1dcca93
author Theodore Ts'o <tytso@mit.edu> 1488061293 -0400
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1524555252 +0200

random: use a tighter cap in credit_entropy_bits_safe()

commit 9f886f4d1d292442b2f22a0a33321eae821bde40 upstream.

This fixes a harmless UBSAN where root could potentially end up
causing an overflow while bumping the entropy_total field (which is
ignored once the entropy pool has been initialized, and this generally
is completed during the boot sequence).

This is marginal for the stable kernel series, but it's a really
trivial patch, and it fixes UBSAN warning that might cause security
folks to get overly excited for no reason.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reported-by: Chen Feng <puck.chen@hisilicon.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>