linux.git/include/net, branch v5.16-rc4

ipv4: convert fib_num_tclassid_users to atomic_t

2021-12-02T11:56:04+00:00

Before commit faa041a40b9f ("ipv4: Create cleanup helper for fib_nh")
changes to net->ipv4.fib_num_tclassid_users were protected by RTNL.

After the change, this is no longer the case, as free_fib_info_rcu()
runs after rcu grace period, without rtnl being held.

Fixes: faa041a40b9f ("ipv4: Create cleanup helper for fib_nh")
Signed-off-by: Eric Dumazet 
Cc: David Ahern 
Reviewed-by: David Ahern 
Signed-off-by: David S. Miller

net: avoid uninit-value from tcp_conn_request

2021-12-02T03:15:54+00:00

A recent change triggers a KMSAN warning, because request
sockets do not initialize @sk_rx_queue_mapping field.

Add sk_rx_queue_update() helper to make our intent clear.

BUG: KMSAN: uninit-value in sk_rx_queue_set include/net/sock.h:1922 [inline]
BUG: KMSAN: uninit-value in tcp_conn_request+0x3bcc/0x4dc0 net/ipv4/tcp_input.c:6922
 sk_rx_queue_set include/net/sock.h:1922 [inline]
 tcp_conn_request+0x3bcc/0x4dc0 net/ipv4/tcp_input.c:6922
 tcp_v4_conn_request+0x218/0x2a0 net/ipv4/tcp_ipv4.c:1528
 tcp_rcv_state_process+0x2c5/0x3290 net/ipv4/tcp_input.c:6406
 tcp_v4_do_rcv+0xb4e/0x1330 net/ipv4/tcp_ipv4.c:1738
 tcp_v4_rcv+0x468d/0x4ed0 net/ipv4/tcp_ipv4.c:2100
 ip_protocol_deliver_rcu+0x760/0x10b0 net/ipv4/ip_input.c:204
 ip_local_deliver_finish net/ipv4/ip_input.c:231 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ip_local_deliver+0x584/0x8c0 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:460 [inline]
 ip_sublist_rcv_finish net/ipv4/ip_input.c:551 [inline]
 ip_list_rcv_finish net/ipv4/ip_input.c:601 [inline]
 ip_sublist_rcv+0x11fd/0x1520 net/ipv4/ip_input.c:609
 ip_list_rcv+0x95f/0x9a0 net/ipv4/ip_input.c:644
 __netif_receive_skb_list_ptype net/core/dev.c:5505 [inline]
 __netif_receive_skb_list_core+0xe34/0x1240 net/core/dev.c:5553
 __netif_receive_skb_list+0x7fc/0x960 net/core/dev.c:5605
 netif_receive_skb_list_internal+0x868/0xde0 net/core/dev.c:5696
 gro_normal_list net/core/dev.c:5850 [inline]
 napi_complete_done+0x579/0xdd0 net/core/dev.c:6587
 virtqueue_napi_complete drivers/net/virtio_net.c:339 [inline]
 virtnet_poll+0x17b6/0x2350 drivers/net/virtio_net.c:1557
 __napi_poll+0x14e/0xbc0 net/core/dev.c:7020
 napi_poll net/core/dev.c:7087 [inline]
 net_rx_action+0x824/0x1880 net/core/dev.c:7174
 __do_softirq+0x1fe/0x7eb kernel/softirq.c:558
 invoke_softirq+0xa4/0x130 kernel/softirq.c:432
 __irq_exit_rcu kernel/softirq.c:636 [inline]
 irq_exit_rcu+0x76/0x130 kernel/softirq.c:648
 common_interrupt+0xb6/0xd0 arch/x86/kernel/irq.c:240
 asm_common_interrupt+0x1e/0x40
 smap_restore arch/x86/include/asm/smap.h:67 [inline]
 get_shadow_origin_ptr mm/kmsan/instrumentation.c:31 [inline]
 __msan_metadata_ptr_for_load_1+0x28/0x30 mm/kmsan/instrumentation.c:63
 tomoyo_check_acl+0x1b0/0x630 security/tomoyo/domain.c:173
 tomoyo_path_permission security/tomoyo/file.c:586 [inline]
 tomoyo_check_open_permission+0x61f/0xe10 security/tomoyo/file.c:777
 tomoyo_file_open+0x24f/0x2d0 security/tomoyo/tomoyo.c:311
 security_file_open+0xb1/0x1f0 security/security.c:1635
 do_dentry_open+0x4e4/0x1bf0 fs/open.c:809
 vfs_open+0xaf/0xe0 fs/open.c:957
 do_open fs/namei.c:3426 [inline]
 path_openat+0x52f1/0x5dd0 fs/namei.c:3559
 do_filp_open+0x306/0x760 fs/namei.c:3586
 do_sys_openat2+0x263/0x8f0 fs/open.c:1212
 do_sys_open fs/open.c:1228 [inline]
 __do_sys_open fs/open.c:1236 [inline]
 __se_sys_open fs/open.c:1232 [inline]
 __x64_sys_open+0x314/0x380 fs/open.c:1232
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Uninit was created at:
 __alloc_pages+0xbc7/0x10a0 mm/page_alloc.c:5409
 alloc_pages+0x8a5/0xb80
 alloc_slab_page mm/slub.c:1810 [inline]
 allocate_slab+0x287/0x1c20 mm/slub.c:1947
 new_slab mm/slub.c:2010 [inline]
 ___slab_alloc+0xbdf/0x1e90 mm/slub.c:3039
 __slab_alloc mm/slub.c:3126 [inline]
 slab_alloc_node mm/slub.c:3217 [inline]
 slab_alloc mm/slub.c:3259 [inline]
 kmem_cache_alloc+0xbb3/0x11c0 mm/slub.c:3264
 reqsk_alloc include/net/request_sock.h:91 [inline]
 inet_reqsk_alloc+0xaf/0x8b0 net/ipv4/tcp_input.c:6712
 tcp_conn_request+0x910/0x4dc0 net/ipv4/tcp_input.c:6852
 tcp_v4_conn_request+0x218/0x2a0 net/ipv4/tcp_ipv4.c:1528
 tcp_rcv_state_process+0x2c5/0x3290 net/ipv4/tcp_input.c:6406
 tcp_v4_do_rcv+0xb4e/0x1330 net/ipv4/tcp_ipv4.c:1738
 tcp_v4_rcv+0x468d/0x4ed0 net/ipv4/tcp_ipv4.c:2100
 ip_protocol_deliver_rcu+0x760/0x10b0 net/ipv4/ip_input.c:204
 ip_local_deliver_finish net/ipv4/ip_input.c:231 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ip_local_deliver+0x584/0x8c0 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:460 [inline]
 ip_sublist_rcv_finish net/ipv4/ip_input.c:551 [inline]
 ip_list_rcv_finish net/ipv4/ip_input.c:601 [inline]
 ip_sublist_rcv+0x11fd/0x1520 net/ipv4/ip_input.c:609
 ip_list_rcv+0x95f/0x9a0 net/ipv4/ip_input.c:644
 __netif_receive_skb_list_ptype net/core/dev.c:5505 [inline]
 __netif_receive_skb_list_core+0xe34/0x1240 net/core/dev.c:5553
 __netif_receive_skb_list+0x7fc/0x960 net/core/dev.c:5605
 netif_receive_skb_list_internal+0x868/0xde0 net/core/dev.c:5696
 gro_normal_list net/core/dev.c:5850 [inline]
 napi_complete_done+0x579/0xdd0 net/core/dev.c:6587
 virtqueue_napi_complete drivers/net/virtio_net.c:339 [inline]
 virtnet_poll+0x17b6/0x2350 drivers/net/virtio_net.c:1557
 __napi_poll+0x14e/0xbc0 net/core/dev.c:7020
 napi_poll net/core/dev.c:7087 [inline]
 net_rx_action+0x824/0x1880 net/core/dev.c:7174
 __do_softirq+0x1fe/0x7eb kernel/softirq.c:558

Fixes: 342159ee394d ("net: avoid dirtying sk->sk_rx_queue_mapping")
Signed-off-by: Eric Dumazet 
Reported-by: syzbot 
Link: https://lore.kernel.org/r/20211130182939.2584764-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski

wireguard: device: reset peer src endpoint when netns exits

2021-11-30T03:50:45+00:00

Each peer's endpoint contains a dst_cache entry that takes a reference
to another netdev. When the containing namespace exits, we take down the
socket and prevent future sockets from being created (by setting
creating_net to NULL), which removes that potential reference on the
netns. However, it doesn't release references to the netns that a netdev
cached in dst_cache might be taking, so the netns still might fail to
exit. Since the socket is gimped anyway, we can simply clear all the
dst_caches (by way of clearing the endpoint src), which will release all
references.

However, the current dst_cache_reset function only releases those
references lazily. But it turns out that all of our usages of
wg_socket_clear_peer_endpoint_src are called from contexts that are not
exactly high-speed or bottle-necked. For example, when there's
connection difficulty, or when userspace is reconfiguring the interface.
And in particular for this patch, when the netns is exiting. So for
those cases, it makes more sense to call dst_release immediately. For
that, we add a small helper function to dst_cache.

This patch also adds a test to netns.sh from Hangbin Liu to ensure this
doesn't regress.

Tested-by: Hangbin Liu 
Reported-by: Xiumei Mu 
Cc: Toke Høiland-Jørgensen 
Cc: Paolo Abeni 
Fixes: 900575aa33a3 ("wireguard: device: avoid circular netns references")
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Jakub Kicinski

ipv6: fix memory leak in fib6_rule_suppress

2021-11-29T14:43:35+00:00

The kernel leaks memory when a `fib` rule is present in IPv6 nftables
firewall rules and a suppress_prefix rule is present in the IPv6 routing
rules (used by certain tools such as wg-quick). In such scenarios, every
incoming packet will leak an allocation in `ip6_dst_cache` slab cache.

After some hours of `bpftrace`-ing and source code reading, I tracked
down the issue to ca7a03c41753 ("ipv6: do not free rt if
FIB_LOOKUP_NOREF is set on suppress rule").

The problem with that change is that the generic `args->flags` always have
`FIB_LOOKUP_NOREF` set[1][2] but the IPv6-specific flag
`RT6_LOOKUP_F_DST_NOREF` might not be, leading to `fib6_rule_suppress` not
decreasing the refcount when needed.

How to reproduce:
 - Add the following nftables rule to a prerouting chain:
     meta nfproto ipv6 fib saddr . mark . iif oif missing drop
   This can be done with:
     sudo nft create table inet test
     sudo nft create chain inet test test_chain '{ type filter hook prerouting priority filter + 10; policy accept; }'
     sudo nft add rule inet test test_chain meta nfproto ipv6 fib saddr . mark . iif oif missing drop
 - Run:
     sudo ip -6 rule add table main suppress_prefixlength 0
 - Watch `sudo slabtop -o | grep ip6_dst_cache` to see memory usage increase
   with every incoming ipv6 packet.

This patch exposes the protocol-specific flags to the protocol
specific `suppress` function, and check the protocol-specific `flags`
argument for RT6_LOOKUP_F_DST_NOREF instead of the generic
FIB_LOOKUP_NOREF when decreasing the refcount, like this.

[1]: https://github.com/torvalds/linux/blob/ca7a03c4175366a92cee0ccc4fec0038c3266e26/net/ipv6/fib6_rules.c#L71
[2]: https://github.com/torvalds/linux/blob/ca7a03c4175366a92cee0ccc4fec0038c3266e26/net/ipv6/fib6_rules.c#L99

Link: https://bugzilla.kernel.org/show_bug.cgi?id=215105
Fixes: ca7a03c41753 ("ipv6: do not free rt if FIB_LOOKUP_NOREF is set on suppress rule")
Cc: stable@vger.kernel.org
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: David S. Miller

tcp: fix page frag corruption on page fault

2021-11-29T12:13:51+00:00

Steffen reported a TCP stream corruption for HTTP requests
served by the apache web-server using a cifs mount-point
and memory mapping the relevant file.

The root cause is quite similar to the one addressed by
commit 20eb4f29b602 ("net: fix sk_page_frag() recursion from
memory reclaim"). Here the nested access to the task page frag
is caused by a page fault on the (mmapped) user-space memory
buffer coming from the cifs file.

The page fault handler performs an smb transaction on a different
socket, inside the same process context. Since sk->sk_allaction
for such socket does not prevent the usage for the task_frag,
the nested allocation modify "under the hood" the page frag
in use by the outer sendmsg call, corrupting the stream.

The overall relevant stack trace looks like the following:

httpd 78268 [001] 3461630.850950:      probe:tcp_sendmsg_locked:
        ffffffff91461d91 tcp_sendmsg_locked+0x1
        ffffffff91462b57 tcp_sendmsg+0x27
        ffffffff9139814e sock_sendmsg+0x3e
        ffffffffc06dfe1d smb_send_kvec+0x28
        [...]
        ffffffffc06cfaf8 cifs_readpages+0x213
        ffffffff90e83c4b read_pages+0x6b
        ffffffff90e83f31 __do_page_cache_readahead+0x1c1
        ffffffff90e79e98 filemap_fault+0x788
        ffffffff90eb0458 __do_fault+0x38
        ffffffff90eb5280 do_fault+0x1a0
        ffffffff90eb7c84 __handle_mm_fault+0x4d4
        ffffffff90eb8093 handle_mm_fault+0xc3
        ffffffff90c74f6d __do_page_fault+0x1ed
        ffffffff90c75277 do_page_fault+0x37
        ffffffff9160111e page_fault+0x1e
        ffffffff9109e7b5 copyin+0x25
        ffffffff9109eb40 _copy_from_iter_full+0xe0
        ffffffff91462370 tcp_sendmsg_locked+0x5e0
        ffffffff91462370 tcp_sendmsg_locked+0x5e0
        ffffffff91462b57 tcp_sendmsg+0x27
        ffffffff9139815c sock_sendmsg+0x4c
        ffffffff913981f7 sock_write_iter+0x97
        ffffffff90f2cc56 do_iter_readv_writev+0x156
        ffffffff90f2dff0 do_iter_write+0x80
        ffffffff90f2e1c3 vfs_writev+0xa3
        ffffffff90f2e27c do_writev+0x5c
        ffffffff90c042bb do_syscall_64+0x5b
        ffffffff916000ad entry_SYSCALL_64_after_hwframe+0x65

The cifs filesystem rightfully sets sk_allocations to GFP_NOFS,
we can avoid the nesting using the sk page frag for allocation
lacking the __GFP_FS flag. Do not define an additional mm-helper
for that, as this is strictly tied to the sk page frag usage.

v1 -> v2:
 - use a stricted sk_page_frag() check instead of reordering the
   code (Eric)

Reported-by: Steffen Froemer 
Fixes: 5640f7685831 ("net: use a per task frag allocator")
Signed-off-by: Paolo Abeni 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller

Merge tag 'ieee802154-for-net-2021-11-24' of git://git.kernel.org/pub/scm/linux/kernel/git/sschmidt/wpan

2021-11-25T01:02:44+00:00

Stefan Schmidt says:

====================
pull-request: ieee802154 for net 2021-11-24

A fix from Alexander which has been brought up various times found by
automated checkers. Make sure values are in u32 range.

* tag 'ieee802154-for-net-2021-11-24' of git://git.kernel.org/pub/scm/linux/kernel/git/sschmidt/wpan:
  net: ieee802154: handle iftypes as u32
====================

Link: https://lore.kernel.org/r/20211124150934.3670248-1-stefan@datenfreihafen.org
Signed-off-by: Jakub Kicinski

net: ipv6: add fib6_nh_release_dsts stub

2021-11-22T15:44:49+00:00

We need a way to release a fib6_nh's per-cpu dsts when replacing
nexthops otherwise we can end up with stale per-cpu dsts which hold net
device references, so add a new IPv6 stub called fib6_nh_release_dsts.
It must be used after an RCU grace period, so no new dsts can be created
through a group's nexthop entry.
Similar to fib6_nh_release it shouldn't be used if fib6_nh_init has failed
so it doesn't need a dummy stub when IPv6 is not enabled.

Fixes: 7bf4796dd099 ("nexthops: add support for replace")
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

page_pool: Revert "page_pool: disable dma mapping support..."

2021-11-18T11:29:40+00:00

This reverts commit d00e60ee54b12de945b8493cf18c1ada9e422514.

As reported by Guillaume in [1]:
Enabling LPAE always enables CONFIG_ARCH_DMA_ADDR_T_64BIT
in 32-bit systems, which breaks the bootup proceess when a
ethernet driver is using page pool with PP_FLAG_DMA_MAP flag.
As we were hoping we had no active consumers for such system
when we removed the dma mapping support, and LPAE seems like
a common feature for 32 bits system, so revert it.

1. https://www.spinics.net/lists/netdev/msg779890.html

Fixes: d00e60ee54b1 ("page_pool: disable dma mapping support for 32-bit arch with 64-bit DMA")
Signed-off-by: Yunsheng Lin 
Reported-by: "kernelci.org bot" 
Tested-by: "kernelci.org bot" 
Acked-by: Jesper Dangaard Brouer 
Acked-by: Ilias Apalodimas 
Signed-off-by: David S. Miller

NFC: add NCI_UNREG flag to eliminate the race

2021-11-18T04:17:05+00:00

There are two sites that calls queue_work() after the
destroy_workqueue() and lead to possible UAF.

The first site is nci_send_cmd(), which can happen after the
nci_close_device as below

nfcmrvl_nci_unregister_dev   |  nfc_genl_dev_up
  nci_close_device           |
    flush_workqueue          |
    del_timer_sync           |
  nci_unregister_device      |    nfc_get_device
    destroy_workqueue        |    nfc_dev_up
    nfc_unregister_device    |      nci_dev_up
      device_del             |        nci_open_device
                             |          __nci_request
                             |            nci_send_cmd
                             |              queue_work !!!

Another site is nci_cmd_timer, awaked by the nci_cmd_work from the
nci_send_cmd.

  ...                        |  ...
  nci_unregister_device      |  queue_work
    destroy_workqueue        |
    nfc_unregister_device    |  ...
      device_del             |  nci_cmd_work
                             |  mod_timer
                             |  ...
                             |  nci_cmd_timer
                             |    queue_work !!!

For the above two UAF, the root cause is that the nfc_dev_up can race
between the nci_unregister_device routine. Therefore, this patch
introduce NCI_UNREG flag to easily eliminate the possible race. In
addition, the mutex_lock in nci_close_device can act as a barrier.

Signed-off-by: Lin Ma 
Fixes: 6a2968aaf50c ("NFC: basic NCI protocol implementation")
Reviewed-by: Jakub Kicinski 
Reviewed-by: Krzysztof Kozlowski 
Link: https://lore.kernel.org/r/20211116152732.19238-1-linma@zju.edu.cn
Signed-off-by: Jakub Kicinski

net: ieee802154: handle iftypes as u32

2021-11-16T17:02:46+00:00

This patch fixes an issue that an u32 netlink value is handled as a
signed enum value which doesn't fit into the range of u32 netlink type.
If it's handled as -1 value some BIT() evaluation ends in a
shift-out-of-bounds issue. To solve the issue we set the to u32 max which
is s32 "-1" value to keep backwards compatibility and let the followed enum
values start counting at 0. This brings the compiler to never handle the
enum as signed and a check if the value is above NL802154_IFTYPE_MAX should
filter -1 out.

Fixes: f3ea5e44231a ("ieee802154: add new interface command")
Signed-off-by: Alexander Aring 
Link: https://lore.kernel.org/r/20211112030916.685793-1-aahringo@redhat.com
Signed-off-by: Stefan Schmidt