[PATCH 0/1] Small potential fix for shiftfs

[PATCH 0/1] Small potential fix for shiftfs

[Oleksandr Natalenko]

Hey, people.

I was lurking at shiftfs just out of curiosity and managed to bump into
a compiler warning that is (as I suppose) easily fixed by the subsequent
patch.

Feel free to drag this into your Ubuntu tree if needed. I haven't played
with it yet, just compiling (because I'm looking for something that is
bindfs but in-kernel) :).

Oleksandr Natalenko (1):
  shiftfs-5.2: use copy_from_user() correctly

 fs/shiftfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

-- 
2.22.1

[PATCH 1/1] shiftfs-5.2: use copy_from_user() correctly

[Oleksandr Natalenko]

Signed-off-by: Oleksandr Natalenko <oleksandr@redhat.com>
---
 fs/shiftfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/shiftfs.c b/fs/shiftfs.c
index 49f6714e9f95..14f3764577d8 100644
--- a/fs/shiftfs.c
+++ b/fs/shiftfs.c
@@ -1526,7 +1526,7 @@ static bool in_ioctl_whitelist(int flag, unsigned long arg)
 	case BTRFS_IOC_SUBVOL_GETFLAGS:
 		return true;
 	case BTRFS_IOC_SUBVOL_SETFLAGS:
-		if (copy_from_user(&flags, arg, sizeof(flags)))
+		if (copy_from_user(&flags, argp, sizeof(flags)))
 			return false;
 
 		if (flags & ~BTRFS_SUBVOL_RDONLY)
-- 
2.22.1

Re: [PATCH 0/1] Small potential fix for shiftfs

[Seth Forshee]

On Thu, Aug 15, 2019 at 04:36:02PM +0200, Oleksandr Natalenko wrote:
> Hey, people.
> 
> I was lurking at shiftfs just out of curiosity and managed to bump into
> a compiler warning that is (as I suppose) easily fixed by the subsequent
> patch.
> 
> Feel free to drag this into your Ubuntu tree if needed. I haven't played
> with it yet, just compiling (because I'm looking for something that is
> bindfs but in-kernel) :).

Thanks for the patch. Christian has actually already sent a patch for
this along with another patch which is still under review:

https://lists.ubuntu.com/archives/kernel-team/2019-July/102449.html

Also note that currently shiftfs is only in Ubuntu distro kernels, and
Ubuntu-specific kernel patches should be directed at
kernel-team@lists.ubuntu.com rather than lkml. If you'll be at LPC,
there's a session to discuss the future of upstreaming shiftfs that you
might find interesting.

Thanks!
Seth