This is a note to let you know that I've just added the patch titled
arc: kernel: Return -EFAULT if copy_to_user() fails
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arc-kernel-return-efault-if-copy_to_user-fails.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 8497368e7708ddb5e7e5e4cde0d231f95d452891
Author: Wang Qing <wangqing@xxxxxxxx>
Date: Mon Mar 1 20:05:48 2021 +0800
arc: kernel: Return -EFAULT if copy_to_user() fails
[ Upstream commit 46e152186cd89d940b26726fff11eb3f4935b45a ]
The copy_to_user() function returns the number of bytes remaining to be
copied, but we want to return -EFAULT if the copy doesn't complete.
Signed-off-by: Wang Qing <wangqing@xxxxxxxx>
Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/arc/kernel/signal.c b/arch/arc/kernel/signal.c
index 257b8699efde..639f39f39917 100644
--- a/arch/arc/kernel/signal.c
+++ b/arch/arc/kernel/signal.c
@@ -97,7 +97,7 @@ stash_usr_regs(struct rt_sigframe __user *sf, struct pt_regs *regs,
sizeof(sf->uc.uc_mcontext.regs.scratch));
err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(sigset_t));
- return err;
+ return err ? -EFAULT : 0;
}
static int restore_usr_regs(struct pt_regs *regs, struct rt_sigframe __user *sf)
@@ -111,7 +111,7 @@ static int restore_usr_regs(struct pt_regs *regs, struct rt_sigframe __user *sf)
&(sf->uc.uc_mcontext.regs.scratch),
sizeof(sf->uc.uc_mcontext.regs.scratch));
if (err)
- return err;
+ return -EFAULT;
set_current_blocked(&set);
regs->bta = uregs.scratch.bta;
