Eric Lee / smarc-ti-linux-kernel

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Commit e8e3b6ddd0a6afa267029141946918392b425cf4

Authored by Sasha Levin
Committed by Greg Kroah-Hartman
1 parent 5f4d5404ee

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>

Showing 1 changed file with 7 additions and 0 deletions Side-by-side Diff

... ... @@ -633,6 +633,13 @@
633 633 if ((txc->modes & ADJ_SETOFFSET) && (!capable(CAP_SYS_TIME)))
634 634 return -EPERM;
635 635  
  636 + if (txc->modes & ADJ_FREQUENCY) {
  637 + if (LONG_MIN / PPM_SCALE > txc->freq)
  638 + return -EINVAL;
  639 + if (LONG_MAX / PPM_SCALE < txc->freq)
  640 + return -EINVAL;
  641 + }
  642 +
636 643 return 0;
637 644 }
638 645