FAILED: patch "[PATCH] posix-timers: Preserve return value in clock_adjtime32()" failed to apply to 4.19-stable tree

The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 2d036dfa5f10df9782f5278fc591d79d283c1fad Mon Sep 17 00:00:00 2001
From: Chen Jun <[email protected]>
Date: Wed, 14 Apr 2021 03:04:49 +0000
Subject: [PATCH] posix-timers: Preserve return value in clock_adjtime32()

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 ]

index bf540f5a4115..dd5697d7347b 100644
@@ -1191,8 +1191,8 @@ SYSCALL_DEFINE2(clock_adjtime32, clockid_t, which_clock,
 
 	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;
 }

From: Chen Jun <[email protected]>

commit 2d036dfa5f10df9782f5278fc591d79d283c1fad upstream.

The return value on success (>= 0) is overwritten by the return value of compat_put_timex(). That works correct in the fault case, but is wrong for the success case where compat_put_timex() returns 0.

Just check the return value of compat_put_timex() and return -EFAULT in case it is not zero.

[ tglx: Massage changelog ]
[ tglx: Backport to 4.19, 4.14 ]

---
 kernel/time/posix-timers.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

@@ -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;
 }

Thanks, now queued up.

greg k-h