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| author | Richard Cochran <richardcochran@gmail.com> | 2011-04-04 08:31:23 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-04-04 08:31:23 -0700 |
| commit | 4352d9d44b935e4d000be6ec89ddb55c2bf35f24 (patch) | |
| tree | 26b9d37f5a41b4c01d800a444ad230eafb48e47a /kernel | |
| parent | b3b896c73b4b04b506816a09994192e3a54f0fef (diff) | |
| download | linux-4352d9d44b935e4d000be6ec89ddb55c2bf35f24.tar.bz2 | |
ntp: fix non privileged system time shifting
The ADJ_SETOFFSET bit added in commit 094aa188 ("ntp: Add ADJ_SETOFFSET
mode bit") 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | 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 5f1bb8e2008f..f6117a4c7cb8 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); |