Messages in this thread Patch in this message | | | Date | Fri, 1 Apr 2011 18:17:35 +0200 | From | Richard Cochran <> | Subject | [PATCH] ntp, security: fix non privileged system time shifting |
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The ADJ_SETOFFSET bit added in commit 094aa188 also introduced a way for any user to change the system time. Sneaky or buggy calls to adjtimex() could set
ADJ_OFFSET_SS_READ | ADJ_SETOFFSET
which would result in a successful call to timekeeping_inject_offset(). This patch fixes the issue by adding the capability check.
Signed-off-by: Richard Cochran <richard.cochran@omicron.at> --- kernel/time/ntp.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 35e68e3..5e65fd5 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -652,6 +652,8 @@ int do_adjtimex(struct timex *txc) struct timespec delta; delta.tv_sec = txc->time.tv_sec; delta.tv_nsec = txc->time.tv_usec; + if (!capable(CAP_SYS_TIME)) + return -EPERM; if (!(txc->modes & ADJ_NANO)) delta.tv_nsec *= 1000; result = timekeeping_inject_offset(&delta); -- 1.7.0.4
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