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authorSasha Levin <sasha.levin@oracle.com>2014-12-03 19:25:05 -0500
committerBen Hutchings <ben@decadent.org.uk>2015-03-06 00:39:19 +0000
commitf20f9084ff23d722a80511a2ce7dc2ea50eb79ad (patch)
tree15d503f24eba9b71312ab54fcbe89e73b613cee2
parent985504f71bb0ca24ac647c72446cc621980aef9f (diff)
downloadlinux-linaro-stable-f20f9084ff23d722a80511a2ce7dc2ea50eb79ad.tar.gz
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.c7
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;