[PATCH 5.11 060/342] posix-timers: Preserve return value in clock_adjtime32()

From: Greg Kroah-Hartman
Date: Mon May 10 2021 - 07:30:01 EST


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
@@ -1191,8 +1191,8 @@ SYSCALL_DEFINE2(clock_adjtime32, clockid

err = do_clock_adjtime(which_clock, &ktx);

- if (err >= 0)
- err = put_old_timex32(utp, &ktx);
+ if (err >= 0 && put_old_timex32(utp, &ktx))
+ return -EFAULT;

return err;
}