diff options
| -rw-r--r-- | include/linux/time.h | 26 | ||||
| -rw-r--r-- | kernel/time/ntp.c | 10 | ||||
| -rw-r--r-- | kernel/time/timekeeping.c | 2 |
3 files changed, 35 insertions, 3 deletions
diff --git a/include/linux/time.h b/include/linux/time.h index beebe3a02d43..297f09f23896 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -125,6 +125,32 @@ static inline bool timeval_valid(const struct timeval *tv) extern struct timespec timespec_trunc(struct timespec t, unsigned gran); +/* + * Validates if a timespec/timeval used to inject a time offset is valid. + * Offsets can be postive or negative. The value of the timeval/timespec + * is the sum of its fields, but *NOTE*: the field tv_usec/tv_nsec must + * always be non-negative. + */ +static inline bool timeval_inject_offset_valid(const struct timeval *tv) +{ + /* We don't check the tv_sec as it can be positive or negative */ + + /* Can't have more microseconds then a second */ + if (tv->tv_usec < 0 || tv->tv_usec >= USEC_PER_SEC) + return false; + return true; +} + +static inline bool timespec_inject_offset_valid(const struct timespec *ts) +{ + /* We don't check the tv_sec as it can be positive or negative */ + + /* Can't have more nanoseconds then a second */ + if (ts->tv_nsec < 0 || ts->tv_nsec >= NSEC_PER_SEC) + return false; + return true; +} + #define CURRENT_TIME (current_kernel_time()) #define CURRENT_TIME_SEC ((struct timespec) { get_seconds(), 0 }) diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 125fc0342355..4073c9550af9 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -676,8 +676,14 @@ int ntp_validate_timex(struct timex *txc) return -EINVAL; } - if ((txc->modes & ADJ_SETOFFSET) && (!capable(CAP_SYS_TIME))) - return -EPERM; + if (txc->modes & ADJ_SETOFFSET) { + /* In order to inject time, you gotta be super-user! */ + if (!capable(CAP_SYS_TIME)) + return -EPERM; + + if (!timeval_inject_offset_valid(&txc->time)) + return -EINVAL; + } /* * Check for potential multiplication overflows that can diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 99188ee5d9d0..d9249daf14ba 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -958,7 +958,7 @@ int timekeeping_inject_offset(struct timespec *ts) struct timespec64 ts64, tmp; int ret = 0; - if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC) + if (!timespec_inject_offset_valid(ts)) return -EINVAL; ts64 = timespec_to_timespec64(*ts); |