Commit 5e5aeb43 authored by Sasha Levin's avatar Sasha Levin Committed by John Stultz

time: adjtimex: Validate the ADJ_FREQUENCY values

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>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
[jstultz: Fix up bug for negative values and drop redunent cap check]
Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
parent 6ada1fc0
...@@ -633,6 +633,13 @@ int ntp_validate_timex(struct timex *txc) ...@@ -633,6 +633,13 @@ int ntp_validate_timex(struct timex *txc)
if ((txc->modes & ADJ_SETOFFSET) && (!capable(CAP_SYS_TIME))) if ((txc->modes & ADJ_SETOFFSET) && (!capable(CAP_SYS_TIME)))
return -EPERM; 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; return 0;
} }
......
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