linux.git/net/core/dev_ioctl.c, branch v5.15

net: core: don't call SIOCBRADD/DELIF for non-bridge devices

2021-08-05T10:36:59+00:00

Commit ad2f99aedf8f ("net: bridge: move bridge ioctls out of .ndo_do_ioctl")
changed SIOCBRADD/DELIF to use bridge's ioctl hook (br_ioctl_hook)
without checking if the target netdevice is actually a bridge which can
cause crashes and generally interpreting other devices' private pointers
as net_bridge pointers.

Crash example (lo - loopback):
$ brctl addif lo ens16
 BUG: kernel NULL pointer dereference, address: 000000000000059898
 #PF: supervisor read access in kernel modede
 #PF: error_code(0x0000) - not-present pagege
 PGD 0 P4D 0 ^Ac
 Oops: 0000 [#1] SMP NOPTI
 CPU: 2 PID: 1376 Comm: brctl Kdump: loaded Tainted: G        W         5.14.0-rc3+ #405
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-4.fc34 04/01/2014
 RIP: 0010:add_del_if+0x1f/0x7c [bridge]
 Code: 80 bf 1b a0 41 5c e9 c0 3c 03 e1 0f 1f 44 00 00 41 55 41 54 41 89 f4 be 0c 00 00 00 55 48 89 fd 53 48 8b 87 88 00 00 00 89 d3 <4c> 8b a8 98 05 00 00 49 8b bd d0 00 00 00 e8 17 d7 f3 e0 84 c0 74
 RSP: 0018:ffff888109d97cb0 EFLAGS: 00010202^Ac
 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: 000000000000000c RDI: ffff888101239bc0
 RBP: ffff888101239bc0 R08: 0000000000000001 R09: 0000000000000000
 R10: ffff888109d97cd8 R11: 00000000000000a3 R12: 0000000000000012
 R13: 0000000000000000 R14: ffff888101239bc0 R15: ffff888109d97e10
 FS:  00007fc1e365b540(0000) GS:ffff88822be80000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000598 CR3: 0000000106506000 CR4: 00000000000006e0
 Call Trace:
  br_ioctl_stub+0x7c/0x441 [bridge]
  br_ioctl_call+0x6d/0x8a
  dev_ifsioc+0x325/0x4e8
  dev_ioctl+0x46b/0x4e1
  sock_do_ioctl+0x7b/0xad
  sock_ioctl+0x2de/0x2f2
  vfs_ioctl+0x1e/0x2b
  __do_sys_ioctl+0x63/0x86
  do_syscall_64+0xcb/0xf2
  entry_SYSCALL_64_after_hwframe+0x44/0xae
 RIP: 0033:0x7fc1e3589427
 Code: 00 00 90 48 8b 05 69 aa 0c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 39 aa 0c 00 f7 d8 64 89 01 48
 RSP: 002b:00007ffc8d501d38 EFLAGS: 00000202 ORIG_RAX: 000000000000001010
 RAX: ffffffffffffffda RBX: 0000000000000012 RCX: 00007fc1e3589427
 RDX: 00007ffc8d501d60 RSI: 00000000000089a3 RDI: 0000000000000003
 RBP: 00007ffc8d501d60 R08: 0000000000000000 R09: fefefeff77686d74
 R10: fffffffffffff8f9 R11: 0000000000000202 R12: 00007ffc8d502e06
 R13: 00007ffc8d502e06 R14: 0000000000000000 R15: 0000000000000000
 Modules linked in: bridge stp llc bonding ipv6 virtio_net [last unloaded: llc]^Ac
 CR2: 0000000000000598

Reported-by: syzbot+79f4a8692e267bdb7227@syzkaller.appspotmail.com
Fixes: ad2f99aedf8f ("net: bridge: move bridge ioctls out of .ndo_do_ioctl")
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

net: bridge: fix ioctl locking

2021-08-05T10:36:59+00:00

Before commit ad2f99aedf8f ("net: bridge: move bridge ioctls out of
.ndo_do_ioctl") the bridge ioctl calls were divided in two parts:
one was deviceless called by sock_ioctl and didn't expect rtnl to be held,
the other was with a device called by dev_ifsioc() and expected rtnl to be
held. After the commit above they were united in a single ioctl stub, but
it didn't take care of the locking expectations.
For sock_ioctl now we acquire  (1) br_ioctl_mutex, (2) rtnl
and for dev_ifsioc we acquire  (1) rtnl,           (2) br_ioctl_mutex

The fix is to get a refcnt on the netdev for dev_ifsioc calls and drop rtnl
then to reacquire it in the bridge ioctl stub after br_ioctl_mutex has
been acquired. That will avoid playing locking games and make the rules
straight-forward: we always take br_ioctl_mutex first, and then rtnl.

Reported-by: syzbot+34fe5894623c4ab1b379@syzkaller.appspotmail.com
Fixes: ad2f99aedf8f ("net: bridge: move bridge ioctls out of .ndo_do_ioctl")
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

net: bonding: move ioctl handling to private ndo operation

2021-07-27T19:11:45+00:00

All other user triggered operations are gone from ndo_ioctl, so move
the SIOCBOND family into a custom operation as well.

The .ndo_ioctl() helper is no longer called by the dev_ioctl.c code now,
but there are still a few definitions in obsolete wireless drivers as well
as the appletalk and ieee802154 layers to call SIOCSIFADDR/SIOCGIFADDR
helpers from inside the kernel.

Cc: Jay Vosburgh 
Cc: Veaceslav Falico 
Cc: Andy Gospodarek 
Signed-off-by: Arnd Bergmann 
Signed-off-by: David S. Miller

net: bridge: move bridge ioctls out of .ndo_do_ioctl

2021-07-27T19:11:45+00:00

Working towards obsoleting the .ndo_do_ioctl operation entirely,
stop passing the SIOCBRADDIF/SIOCBRDELIF device ioctl commands
into this callback.

My first attempt was to add another ndo_siocbr() callback, but
as there is only a single driver that takes these commands and
there is already a hook mechanism to call directly into this
driver, extend this hook instead, and use it for both the
deviceless and the device specific ioctl commands.

Cc: Roopa Prabhu 
Cc: Nikolay Aleksandrov 
Cc: bridge@lists.linux-foundation.org
Signed-off-by: Arnd Bergmann 
Signed-off-by: David S. Miller

net: socket: return changed ifreq from SIOCDEVPRIVATE

2021-07-27T19:11:45+00:00

Some drivers that use SIOCDEVPRIVATE ioctl commands modify
the ifreq structure and expect it to be passed back to user
space, which has never really happened for compat mode
because the calling these drivers through ndo_do_ioctl
requires overwriting the ifr_data pointer.

Now that all drivers are converted to ndo_siocdevprivate,
change it to handle this correctly in both compat and
native mode.

Signed-off-by: Arnd Bergmann 
Signed-off-by: David S. Miller

net: split out ndo_siowandev ioctl

2021-07-27T19:11:45+00:00

In order to further reduce the scope of ndo_do_ioctl(), move
out the SIOCWANDEV handling into a new network device operation
function.

Adjust the prototype to only pass the if_settings sub-structure
in place of the ifreq, and remove the redundant 'cmd' argument
in the process.

Cc: Krzysztof Halasa 
Cc: "Jan \"Yenya\" Kasprzak" 
Cc: Kevin Curtis 
Cc: Zhao Qiang 
Cc: Martin Schiller 
Cc: Jiri Slaby 
Cc: linux-x25@vger.kernel.org
Signed-off-by: Arnd Bergmann 
Signed-off-by: David S. Miller

dev_ioctl: split out ndo_eth_ioctl

2021-07-27T19:11:45+00:00

Most users of ndo_do_ioctl are ethernet drivers that implement
the MII commands SIOCGMIIPHY/SIOCGMIIREG/SIOCSMIIREG, or hardware
timestamping with SIOCSHWTSTAMP/SIOCGHWTSTAMP.

Separate these from the few drivers that use ndo_do_ioctl to
implement SIOCBOND, SIOCBR and SIOCWANDEV commands.

This is a purely cosmetic change intended to help readers find
their way through the implementation.

Cc: Doug Ledford 
Cc: Jason Gunthorpe 
Cc: Jay Vosburgh 
Cc: Veaceslav Falico 
Cc: Andy Gospodarek 
Cc: Andrew Lunn 
Cc: Vivien Didelot 
Cc: Florian Fainelli 
Cc: Vladimir Oltean 
Cc: Leon Romanovsky 
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Arnd Bergmann 
Acked-by: Jason Gunthorpe 
Signed-off-by: David S. Miller

dev_ioctl: pass SIOCDEVPRIVATE data separately

2021-07-27T19:11:44+00:00

The compat handlers for SIOCDEVPRIVATE are incorrect for any driver that
passes data as part of struct ifreq rather than as an ifr_data pointer, or
that passes data back this way, since the compat_ifr_data_ioctl() helper
overwrites the ifr_data pointer and does not copy anything back out.

Since all drivers using devprivate commands are now converted to the
new .ndo_siocdevprivate callback, fix this by adding the missing piece
and passing the pointer separately the whole way.

This further unifies the native and compat logic for socket ioctls,
as the new code now passes the correct pointer as well as the correct
data for both native and compat ioctls.

Signed-off-by: Arnd Bergmann 
Signed-off-by: David S. Miller

net: split out SIOCDEVPRIVATE handling from dev_ioctl

2021-07-27T19:11:43+00:00

SIOCDEVPRIVATE ioctl commands are mainly used in really old
drivers, and they have a number of problems:

- They hide behind the normal .ndo_do_ioctl function that
  is also used for other things in modern drivers, so it's
  hard to spot a driver that actually uses one of these

- Since drivers use a number different calling conventions,
  it is impossible to support compat mode for them in
  a generic way.

- With all drivers using the same 16 commands codes, there
  is no way to introspect the data being passed through
  things like strace.

Add a new net_device_ops callback pointer, to address the
first two of these. Separating them from .ndo_do_ioctl
makes it easy to grep for drivers with a .ndo_siocdevprivate
callback, and the unwieldy name hopefully makes it easier
to spot in code review.

By passing the ifreq structure and the ifr_data pointer
separately, it is no longer necessary to overload these,
and the driver can use either one for a given command.

Cc: Cong Wang 
Signed-off-by: Arnd Bergmann 
Signed-off-by: David S. Miller

net: socket: simplify dev_ifconf handling

2021-07-23T13:20:25+00:00

The dev_ifconf() calling conventions make compat handling
more complicated than necessary, simplify this by moving
the in_compat_syscall() check into the function.

Signed-off-by: Arnd Bergmann 
Reviewed-by: Christoph Hellwig 
Signed-off-by: David S. Miller