Re: [PATCH v5.10-v5.15] Bluetooth: RFCOMM: Fix not validating setsockopt user input

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Jan 24, 2025 at 11:13:53AM +0530, Keerthana Kalyanasundaram wrote:
> On Mon, Jan 20, 2025 at 9:11 PM Greg KH <gregkh@linuxfoundation.org> wrote:
> >
> > On Mon, Jan 20, 2025 at 06:46:47AM +0000, Keerthana K wrote:
> > > From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
> > >
> > > [ Upstream commit a97de7bff13b1cc825c1b1344eaed8d6c2d3e695 ]
> > >
> > > syzbot reported rfcomm_sock_setsockopt_old() is copying data without
> > > checking user input length.
> > >
> > > BUG: KASAN: slab-out-of-bounds in copy_from_sockptr_offset
> > > include/linux/sockptr.h:49 [inline]
> > > BUG: KASAN: slab-out-of-bounds in copy_from_sockptr
> > > include/linux/sockptr.h:55 [inline]
> > > BUG: KASAN: slab-out-of-bounds in rfcomm_sock_setsockopt_old
> > > net/bluetooth/rfcomm/sock.c:632 [inline]
> > > BUG: KASAN: slab-out-of-bounds in rfcomm_sock_setsockopt+0x893/0xa70
> > > net/bluetooth/rfcomm/sock.c:673
> > > Read of size 4 at addr ffff8880209a8bc3 by task syz-executor632/5064
> > >
> > > Fixes: 9f2c8a03fbb3 ("Bluetooth: Replace RFCOMM link mode with security level")
> > > Fixes: bb23c0ab8246 ("Bluetooth: Add support for deferring RFCOMM connection setup")
> > > Reported-by: syzbot <syzkaller@googlegroups.com>
> > > Signed-off-by: Eric Dumazet <edumazet@google.com>
> > > Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
> > > Signed-off-by: Sasha Levin <sashal@kernel.org>
> > > Signed-off-by: Keerthana K <keerthana.kalyanasundaram@broadcom.com>
> > > ---
> > >  net/bluetooth/rfcomm/sock.c | 14 +++++---------
> > >  1 file changed, 5 insertions(+), 9 deletions(-)
> >
> > This breaks the build on 5.15.y systems, did you test it?
> >
> > I'm dropping both patches now, please be more careful.
> >
> Apologies for the build breakage. I will be more careful in the future.
> v5.15.y:
> one patch is missing in v5.15.y. I have added that patch
> https://lore.kernel.org/stable/20250124053306.5028-1-keerthana.kalyanasundaram@broadcom.com/T/#t
> v5.10.y:
> No changes needed. you can pick the same patch from the email chain for v5.10.y

From what "email chain"?  Please just send a v5.10.y patch as well to
make it obvious what we are supposed to do here.

confused,

greg k-h