Commit 5e0fb1b5 authored by Arnd Bergmann's avatar Arnd Bergmann
Browse files

y2038: time: avoid timespec usage in settimeofday() 



The compat_get_timeval() and timeval_valid() interfaces are deprecated
and getting removed along with the definition of struct timeval itself.

Change the two implementations of the settimeofday() system call to
open-code these helpers and completely avoid references to timeval.

The timeval_valid() call is not needed any more here, only a check to
avoid overflowing tv_nsec during the multiplication, as there is another
range check in do_sys_settimeofday64().

Tested-by: default avatar <syzbot+dccce9b26ba09ca49966@syzkaller.appspotmail.com>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parent bde9e963

include/linux/syscalls.h

+1 −1
Original line number Diff line number Diff line
@@ -734,7 +734,7 @@ asmlinkage long sys_getcpu(unsigned __user *cpu, unsigned __user *node, struct g 
/* kernel/time.c */

asmlinkage long sys_gettimeofday(struct __kernel_old_timeval __user *tv,

				struct timezone __user *tz);

asmlinkage long sys_settimeofday(struct timeval __user *tv,

asmlinkage long sys_settimeofday(struct __kernel_old_timeval __user *tv,

				struct timezone __user *tz);

asmlinkage long sys_adjtimex(struct __kernel_timex __user *txc_p);

asmlinkage long sys_adjtimex_time32(struct old_timex32 __user *txc_p);

kernel/time/time.c

+9 −11
Original line number Diff line number Diff line
@@ -196,22 +196,21 @@ int do_sys_settimeofday64(const struct timespec64 *tv, const struct timezone *tz 
	return 0;

}



SYSCALL_DEFINE2(settimeofday, struct timeval __user *, tv,

SYSCALL_DEFINE2(settimeofday, struct __kernel_old_timeval __user *, tv,

		struct timezone __user *, tz)

{

	struct timespec64 new_ts;

	struct timeval user_tv;

	struct timezone new_tz;



	if (tv) {

		if (copy_from_user(&user_tv, tv, sizeof(*tv)))

		if (get_user(new_ts.tv_sec, &tv->tv_sec) ||

		    get_user(new_ts.tv_nsec, &tv->tv_usec))

			return -EFAULT;



		if (!timeval_valid(&user_tv))

		if (new_ts.tv_nsec > USEC_PER_SEC || new_ts.tv_nsec < 0)

			return -EINVAL;



		new_ts.tv_sec = user_tv.tv_sec;

		new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC;

		new_ts.tv_nsec *= NSEC_PER_USEC;

	}

	if (tz) {

		if (copy_from_user(&new_tz, tz, sizeof(*tz)))
@@ -245,18 +244,17 @@ COMPAT_SYSCALL_DEFINE2(settimeofday, struct old_timeval32 __user *, tv, 
		       struct timezone __user *, tz)

{

	struct timespec64 new_ts;

	struct timeval user_tv;

	struct timezone new_tz;



	if (tv) {

		if (compat_get_timeval(&user_tv, tv))

		if (get_user(new_ts.tv_sec, &tv->tv_sec) ||

		    get_user(new_ts.tv_nsec, &tv->tv_usec))

			return -EFAULT;



		if (!timeval_valid(&user_tv))

		if (new_ts.tv_nsec > USEC_PER_SEC || new_ts.tv_nsec < 0)

			return -EINVAL;



		new_ts.tv_sec = user_tv.tv_sec;

		new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC;

		new_ts.tv_nsec *= NSEC_PER_USEC;

	}

	if (tz) {

		if (copy_from_user(&new_tz, tz, sizeof(*tz)))