diff options
| author | Sasha Levin <sasha.levin@oracle.com> | 2014-12-03 19:25:05 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-01-29 17:40:56 -0800 |
| commit | 2497402c9ad62e91897fed5310f7df48bf3bca1f (patch) | |
| tree | a9c8f1c87896308220fca582578dbe908a80526f | |
| parent | 7336dcc2139a09928c3aa04216576d94bcc857d9 (diff) | |
| download | lwn-2497402c9ad62e91897fed5310f7df48bf3bca1f.tar.gz lwn-2497402c9ad62e91897fed5310f7df48bf3bca1f.zip | |
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>
| -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 af8d1d4f3d55..28db9bedc857 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -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; } |