linux-stable.git/net/core/dev.c, branch v6.1.76

net: fix removing a namespace with conflicting altnames

2024-02-01T00:17:04+00:00

[ Upstream commit d09486a04f5da0a812c26217213b89a3b1acf836 ]

Mark reports a BUG() when a net namespace is removed.

    kernel BUG at net/core/dev.c:11520!

Physical interfaces moved outside of init_net get "refunded"
to init_net when that namespace disappears. The main interface
name may get overwritten in the process if it would have
conflicted. We need to also discard all conflicting altnames.
Recent fixes addressed ensuring that altnames get moved
with the main interface, which surfaced this problem.

Reported-by: Марк Коренберг 
Link: https://lore.kernel.org/all/CAEmTpZFZ4Sv3KwqFOY2WKDHeZYdi0O7N5H1nTvcGp=SAEavtDg@mail.gmail.com/
Fixes: 7663d522099e ("net: check for altname conflicts when changing netdev's netns")
Signed-off-by: Jakub Kicinski 
Reviewed-by: Eric Dumazet 
Reviewed-by: Jiri Pirko 
Reviewed-by: Xin Long 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: check dev->gso_max_size in gso_features_check()

2024-01-01T12:38:58+00:00

[ Upstream commit 24ab059d2ebd62fdccc43794796f6ffbabe49ebc ]

Some drivers might misbehave if TSO packets get too big.

GVE for instance uses a 16bit field in its TX descriptor,
and will do bad things if a packet is bigger than 2^16 bytes.

Linux TCP stack honors dev->gso_max_size, but there are
other ways for too big packets to reach an ndo_start_xmit()
handler : virtio_net, af_packet, GRO...

Add a generic check in gso_features_check() and fallback
to GSO when needed.

gso_max_size was added in the blamed commit.

Fixes: 82cc1a7a5687 ("[NET]: Add per-connection option to set max TSO frame size")
Signed-off-by: Eric Dumazet 
Link: https://lore.kernel.org/r/20231219125331.4127498-1-edumazet@google.com
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

net: move altnames together with the netdevice

2023-10-25T10:03:16+00:00

commit 8e15aee621618a3ee3abecaf1fd8c1428098b7ef upstream.

The altname nodes are currently not moved to the new netns
when netdevice itself moves:

  [ ~]# ip netns add test
  [ ~]# ip -netns test link add name eth0 type dummy
  [ ~]# ip -netns test link property add dev eth0 altname some-name
  [ ~]# ip -netns test link show dev some-name
  2: eth0:  mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
      link/ether 1e:67:ed:19:3d:24 brd ff:ff:ff:ff:ff:ff
      altname some-name
  [ ~]# ip -netns test link set dev eth0 netns 1
  [ ~]# ip link
  ...
  3: eth0:  mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
      link/ether 02:40:88:62:ec:b8 brd ff:ff:ff:ff:ff:ff
      altname some-name
  [ ~]# ip li show dev some-name
  Device "some-name" does not exist.

Remove them from the hash table when device is unlisted
and add back when listed again.

Fixes: 36fbf1e52bd3 ("net: rtnetlink: add linkprop commands to add and delete alternative ifnames")
Reviewed-by: Jiri Pirko 
Signed-off-by: Jakub Kicinski 
Signed-off-by: Paolo Abeni 
Signed-off-by: Greg Kroah-Hartman

net: check for altname conflicts when changing netdev's netns

2023-10-25T10:03:08+00:00

commit 7663d522099ecc464512164e660bc771b2ff7b64 upstream.

It's currently possible to create an altname conflicting
with an altname or real name of another device by creating
it in another netns and moving it over:

 [ ~]$ ip link add dev eth0 type dummy

 [ ~]$ ip netns add test
 [ ~]$ ip -netns test link add dev ethX netns test type dummy
 [ ~]$ ip -netns test link property add dev ethX altname eth0
 [ ~]$ ip -netns test link set dev ethX netns 1

 [ ~]$ ip link
 ...
 3: eth0:  mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
     link/ether 02:40:88:62:ec:b8 brd ff:ff:ff:ff:ff:ff
 ...
 5: ethX:  mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
     link/ether 26:b7:28:78:38:0f brd ff:ff:ff:ff:ff:ff
     altname eth0

Create a macro for walking the altnames, this hopefully makes
it clearer that the list we walk contains only altnames.
Which is otherwise not entirely intuitive.

Fixes: 36fbf1e52bd3 ("net: rtnetlink: add linkprop commands to add and delete alternative ifnames")
Reviewed-by: Jiri Pirko 
Signed-off-by: Jakub Kicinski 
Signed-off-by: Paolo Abeni 
Signed-off-by: Greg Kroah-Hartman

net: fix ifname in netlink ntf during netns move

2023-10-25T10:03:08+00:00

commit 311cca40661f428b7aa114fb5af578cfdbe3e8b6 upstream.

dev_get_valid_name() overwrites the netdev's name on success.
This makes it hard to use in prepare-commit-like fashion,
where we do validation first, and "commit" to the change
later.

Factor out a helper which lets us save the new name to a buffer.
Use it to fix the problem of notification on netns move having
incorrect name:

 5: eth0:  mtu 1500 qdisc noop state DOWN group default
     link/ether be:4d:58:f9:d5:40 brd ff:ff:ff:ff:ff:ff
 6: eth1:  mtu 1500 qdisc noop state DOWN group default
     link/ether 1e:4a:34:36:e3:cd brd ff:ff:ff:ff:ff:ff

 [ ~]# ip link set dev eth0 netns 1 name eth1

ip monitor inside netns:
 Deleted inet eth0
 Deleted inet6 eth0
 Deleted 5: eth1:  mtu 1500 qdisc noop state DOWN group default
     link/ether be:4d:58:f9:d5:40 brd ff:ff:ff:ff:ff:ff new-netnsid 0 new-ifindex 7

Name is reported as eth1 in old netns for ifindex 5, already renamed.

Fixes: d90310243fd7 ("net: device name allocation cleanups")
Signed-off-by: Jakub Kicinski 
Reviewed-by: Jiri Pirko 
Signed-off-by: Paolo Abeni 
Signed-off-by: Greg Kroah-Hartman

net: avoid UAF on deleted altname

2023-10-25T10:03:08+00:00

commit 1a83f4a7c156fa6bbd6b530e89fa3270bf3d9d1b upstream.

Altnames are accessed under RCU (dev_get_by_name_rcu())
but freed by kfree() with no synchronization point.

Each node has one or two allocations (node and a variable-size
name, sometimes the name is netdev->name). Adding rcu_heads
here is a bit tedious. Besides most code which unlists the names
already has rcu barriers - so take the simpler approach of adding
synchronize_rcu(). Note that the one on the unregistration path
(which matters more) is removed by the next fix.

Fixes: ff92741270bf ("net: introduce name_node struct to be used in hashlist")
Reviewed-by: Jiri Pirko 
Signed-off-by: Jakub Kicinski 
Signed-off-by: Paolo Abeni 
Signed-off-by: Greg Kroah-Hartman

net: refine debug info in skb_checksum_help()

2023-10-19T21:08:53+00:00

[ Upstream commit 26c29961b142444cd99361644c30fa1e9b3da6be ]

syzbot uses panic_on_warn.

This means that the skb_dump() I added in the blamed commit are
not even called.

Rewrite this so that we get the needed skb dump before syzbot crashes.

Fixes: eeee4b77dc52 ("net: add more debug info in skb_checksum_help()")
Signed-off-by: Eric Dumazet 
Reported-by: Willem de Bruijn 
Reviewed-by: Willem de Bruijn 
Link: https://lore.kernel.org/r/20231006173355.2254983-1-edumazet@google.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

net: sched: add rcu annotations around qdisc->qdisc_sleeping

2023-06-14T09:15:21+00:00

[ Upstream commit d636fc5dd692c8f4e00ae6e0359c0eceeb5d9bdb ]

syzbot reported a race around qdisc->qdisc_sleeping [1]

It is time we add proper annotations to reads and writes to/from
qdisc->qdisc_sleeping.

[1]
BUG: KCSAN: data-race in dev_graft_qdisc / qdisc_lookup_rcu

read to 0xffff8881286fc618 of 8 bytes by task 6928 on cpu 1:
qdisc_lookup_rcu+0x192/0x2c0 net/sched/sch_api.c:331
__tcf_qdisc_find+0x74/0x3c0 net/sched/cls_api.c:1174
tc_get_tfilter+0x18f/0x990 net/sched/cls_api.c:2547
rtnetlink_rcv_msg+0x7af/0x8c0 net/core/rtnetlink.c:6386
netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2546
rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6413
netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
netlink_unicast+0x56f/0x640 net/netlink/af_netlink.c:1365
netlink_sendmsg+0x665/0x770 net/netlink/af_netlink.c:1913
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg net/socket.c:747 [inline]
____sys_sendmsg+0x375/0x4c0 net/socket.c:2503
___sys_sendmsg net/socket.c:2557 [inline]
__sys_sendmsg+0x1e3/0x270 net/socket.c:2586
__do_sys_sendmsg net/socket.c:2595 [inline]
__se_sys_sendmsg net/socket.c:2593 [inline]
__x64_sys_sendmsg+0x46/0x50 net/socket.c:2593
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

write to 0xffff8881286fc618 of 8 bytes by task 6912 on cpu 0:
dev_graft_qdisc+0x4f/0x80 net/sched/sch_generic.c:1115
qdisc_graft+0x7d0/0xb60 net/sched/sch_api.c:1103
tc_modify_qdisc+0x712/0xf10 net/sched/sch_api.c:1693
rtnetlink_rcv_msg+0x807/0x8c0 net/core/rtnetlink.c:6395
netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2546
rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6413
netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
netlink_unicast+0x56f/0x640 net/netlink/af_netlink.c:1365
netlink_sendmsg+0x665/0x770 net/netlink/af_netlink.c:1913
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg net/socket.c:747 [inline]
____sys_sendmsg+0x375/0x4c0 net/socket.c:2503
___sys_sendmsg net/socket.c:2557 [inline]
__sys_sendmsg+0x1e3/0x270 net/socket.c:2586
__do_sys_sendmsg net/socket.c:2595 [inline]
__se_sys_sendmsg net/socket.c:2593 [inline]
__x64_sys_sendmsg+0x46/0x50 net/socket.c:2593
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 6912 Comm: syz-executor.5 Not tainted 6.4.0-rc3-syzkaller-00190-g0d85b27b0cc6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/16/2023

Fixes: 3a7d0d07a386 ("net: sched: extend Qdisc with rcu")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Cc: Vlad Buslov 
Acked-by: Jamal Hadi Salim
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

rfs: annotate lockless accesses to RFS sock flow table

2023-06-14T09:15:21+00:00

[ Upstream commit 5c3b74a92aa285a3df722bf6329ba7ccf70346d6 ]

Add READ_ONCE()/WRITE_ONCE() on accesses to the sock flow table.

This also prevents a (smart ?) compiler to remove the condition in:

if (table->ents[index] != newval)
        table->ents[index] = newval;

We need the condition to avoid dirtying a shared cache line.

Fixes: fec5e652e58f ("rfs: Receive Flow Steering")
Signed-off-by: Eric Dumazet 
Reviewed-by: Simon Horman 
Reviewed-by: Kuniyuki Iwashima 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: Catch invalid index in XPS mapping

2023-05-24T16:32:37+00:00

[ Upstream commit 5dd0dfd55baec0742ba8f5625a0dd064aca7db16 ]

When setting the XPS value of a TX queue, warn the user once if the
index of the queue is greater than the number of allocated TX queues.

Previously, this scenario went uncaught. In the best case, it resulted
in unnecessary allocations. In the worst case, it resulted in
out-of-bounds memory references through calls to `netdev_get_tx_queue(
dev, index)`. Therefore, it is important to inform the user but not
worth returning an error and risk downing the netdevice.

Signed-off-by: Nick Child 
Reviewed-by: Piotr Raczynski 
Link: https://lore.kernel.org/r/20230321150725.127229-1-nnac123@linux.ibm.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin