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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: syzbot+dccce9b26ba09ca49966@syzkaller.appspotmail.com
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
This commit is contained in:
Arnd Bergmann 2018-08-15 20:04:11 +02:00
parent bde9e963af
commit 5e0fb1b57b
2 changed files with 10 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/linux/syscalls.h
View File

@ -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);

20
kernel/time/time.c
View File

@ -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)))