time: adjtimex: Validate the ADJ_FREQUENCY values
commit 5e5aeb4367b450a28f447f6d5ab57d8f2ab16a5f upstream. Verify that the frequency value from userspace is valid and makes sense. Unverified values can cause overflows later on. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> [jstultz: Fix up bug for negative values and drop redunent cap check] Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
7336dcc213
commit
2497402c9a
|
@ -631,6 +631,13 @@ int ntp_validate_timex(struct timex *txc)
|
|||
if ((txc->modes & ADJ_SETOFFSET) && (!capable(CAP_SYS_TIME)))
|
||||
return -EPERM;
|
||||
|
||||
if (txc->modes & ADJ_FREQUENCY) {
|
||||
if (LONG_MIN / PPM_SCALE > txc->freq)
|
||||
return -EINVAL;
|
||||
if (LONG_MAX / PPM_SCALE < txc->freq)
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
|
Loading…
Reference in New Issue