diff options
| author | Sasha Levin <sasha.levin@oracle.com> | 2014-12-03 19:25:05 -0500 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2015-03-06 00:39:19 +0000 |
| commit | f20f9084ff23d722a80511a2ce7dc2ea50eb79ad (patch) | |
| tree | 15d503f24eba9b71312ab54fcbe89e73b613cee2 | |
| parent | 985504f71bb0ca24ac647c72446cc621980aef9f (diff) | |
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>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | kernel/time/ntp.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index f1eb182b5fe0..bca743dd24ae 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -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; |