From: Chen Jun <chenjun102@xxxxxxxxxx> commit 2d036dfa5f10df9782f5278fc591d79d283c1fad upstream. The return value on success (>= 0) is overwritten by the return value of put_old_timex32(). That works correct in the fault case, but is wrong for the success case where put_old_timex32() returns 0. Just check the return value of put_old_timex32() and return -EFAULT in case it is not zero. [ tglx: Massage changelog ] Fixes: 3a4d44b61625 ("ntp: Move adjtimex related compat syscalls to native counterparts") Signed-off-by: Chen Jun <chenjun102@xxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Reviewed-by: Richard Cochran <richardcochran@xxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/20210414030449.90692-1-chenjun102@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/time/posix-timers.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/kernel/time/posix-timers.c +++ b/kernel/time/posix-timers.c @@ -1166,8 +1166,8 @@ COMPAT_SYSCALL_DEFINE2(clock_adjtime, cl err = kc->clock_adj(which_clock, &ktx); - if (err >= 0) - err = compat_put_timex(utp, &ktx); + if (err >= 0 && compat_put_timex(utp, &ktx)) + return -EFAULT; return err; }