Commit f20f9084 authored by Sasha Levin's avatar Sasha Levin Committed by Ben Hutchings

time: adjtimex: Validate the ADJ_FREQUENCY values

commit 5e5aeb43 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: 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>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
parent 985504f7
......@@ -608,6 +608,13 @@ int do_adjtimex(struct timex *txc)
return -EINVAL;
}
if (txc->modes & ADJ_FREQUENCY) {
if (LONG_MIN / PPM_SCALE > txc->freq)
return -EINVAL;
if (LONG_MAX / PPM_SCALE < txc->freq)
return -EINVAL;
}
if (txc->modes & ADJ_SETOFFSET) {
struct timespec delta;
delta.tv_sec = txc->time.tv_sec;
......
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