ppdev: prevent overflow when setting port timeout

PPSETTIME64 supplies the timeval fields as s64 values, but
pp_set_timeout() narrows tv_usec to int and calculates tv_sec * HZ in a
signed long. Large positive values can therefore be truncated or overflow
and install an unintended timeout.

Keep both fields as s64, reject a non-canonical microsecond value, and
use timespec64_to_jiffies() to cap excessively large timeouts at
MAX_JIFFY_OFFSET. This is a behavior change because both PPSETTIME
ioctls could previously accept values with tv_usec >= USEC_PER_SEC.
The validation follows the precedent set by sock_set_timeout().

Fixes: 3b9ab374a1e6 ("ppdev: convert to y2038 safe")
Signed-off-by: Linmao Li <lilinmao@kylinos.cn>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patch.msgid.link/20260716013923.19494-1-lilinmao@kylinos.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

0 files changed, 0 insertions, 0 deletions