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| author | Sasha Levin <sasha.levin@oracle.com> | 2014-12-03 19:25:05 -0500 |
|---|---|---|
| committer | John Stultz <john.stultz@linaro.org> | 2015-01-07 09:50:32 -0800 |
| commit | 5e5aeb4367b450a28f447f6d5ab57d8f2ab16a5f (patch) | |
| tree | 13c92234f198f0cc9147b65f4d90bcb15018f9e9 /kernel/time/ntp.c | |
| parent | 6ada1fc0e1c4775de0e043e1bd3ae9d065491aa5 (diff) | |
| download | lwn-5e5aeb4367b450a28f447f6d5ab57d8f2ab16a5f.tar.gz lwn-5e5aeb4367b450a28f447f6d5ab57d8f2ab16a5f.zip | |
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: 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>
Diffstat (limited to 'kernel/time/ntp.c')
| -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 87a346fd6d61..28bf91c60a0b 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -633,6 +633,13 @@ 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; } |