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  7. 11 Feb, 2022 11 commits
    • Alexei Starovoitov's avatar
      Merge branch 'bpf: fix a bpf_timer initialization issue' · 3df9d803
      Alexei Starovoitov authored 
      Yonghong Song says:

====================

The patch [1] exposed a bpf_timer initialization bug in function
check_and_init_map_value(). With bug fix here, the patch [1]
can be applied with all selftests passed. Please see individual
patches for fix details.

  [1] https://lore.kernel.org/bpf/20220209070324.1093182-2-memxor@gmail.com/

Changelog:
  v3 -> v4:
    . move header file in patch #1 to avoid bpf-next merge conflict
  v2 -> v3:
    . switch patch #1 and patch #2 for better bisecting
  v1 -> v2:
    . add Fixes tag for patch #1
    . rebase against bpf tree
====================
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
      3df9d803
    • Yonghong Song's avatar
      bpf: Fix a bpf_timer initialization issue · 5eaed6ee
      Yonghong Song authored 
      The patch in [1] intends to fix a bpf_timer related issue,
but the fix caused existing 'timer' selftest to fail with
hang or some random errors. After some debug, I found
an issue with check_and_init_map_value() in the hashtab.c.
More specifically, in hashtab.c, we have code
  l_new = bpf_map_kmalloc_node(&htab->map, ...)
  check_and_init_map_value(&htab->map, l_new...)
Note that bpf_map_kmalloc_node() does not do initialization
so l_new contains random value.

The function check_and_init_map_value() intends to zero the
bpf_spin_lock and bpf_timer if they exist in the map.
But I found bpf_spin_lock is zero'ed but bpf_timer is not zero'ed.
With [1], later copy_map_value() skips copying of
bpf_spin_lock and bpf_timer. The non-zero bpf_timer caused
random failures for 'timer' selftest.
Without [1], for both bpf_spin_lock and bpf_timer case,
bpf_timer will be zero'ed, so 'timer' self test is okay.

For check_and_init_map_value(), why bpf_spin_lock is zero'ed
properly while bpf_timer not. In bpf uapi header, we have
  struct bpf_spin_lock {
        __u32   val;
  };
  struct bpf_timer {
        __u64 :64;
        __u64 :64;
  } __attribute__((aligned(8)));

The initialization code:
  *(struct bpf_spin_lock *)(dst + map->spin_lock_off) =
      (struct bpf_spin_lock){};
  *(struct bpf_timer *)(dst + map->timer_off) =
      (struct bpf_timer){};
It appears the compiler has no obligation to initialize anonymous fields.
For example, let us use clang with bpf target as below:
  $ cat t.c
  struct bpf_timer {
        unsigned long long :64;
  };
  struct bpf_timer2 {
        unsigned long long a;
  };

  void test(struct bpf_timer *t) {
    *t = (struct bpf_timer){};
  }
  void test2(struct bpf_timer2 *t) {
    *t = (struct bpf_timer2){};
  }
  $ clang -target bpf -O2 -c -g t.c
  $ llvm-objdump -d t.o
   ...
   0000000000000000 <test>:
       0:       95 00 00 00 00 00 00 00 exit
   0000000000000008 <test2>:
       1:       b7 02 00 00 00 00 00 00 r2 = 0
       2:       7b 21 00 00 00 00 00 00 *(u64 *)(r1 + 0) = r2
       3:       95 00 00 00 00 00 00 00 exit

gcc11.2 does not have the above issue. But from
  INTERNATIONAL STANDARD ©ISO/IEC ISO/IEC 9899:201x
  Programming languages — C
  http://www.open-std.org/Jtc1/sc22/wg14/www/docs/n1547.pdf
  page 157:
  Except where explicitly stated otherwise, for the purposes of
  this subclause unnamed members of objects of structure and union
  type do not participate in initialization. Unnamed members of
  structure objects have indeterminate value even after initialization.

To fix the problem, let use memset for bpf_timer case in
check_and_init_map_value(). For consistency, memset is also
used for bpf_spin_lock case.

  [1] https://lore.kernel.org/bpf/20220209070324.1093182-2-memxor@gmail.com/

Fixes: 68134668 ("bpf: Add map side support for bpf timers.")
Signed-off-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220211194953.3142152-1-yhs@fb.com
      5eaed6ee
    • Yonghong Song's avatar
      bpf: Emit bpf_timer in vmlinux BTF · 3bd916ee
      Yonghong Song authored 
      Currently the following code in check_and_init_map_value()
  *(struct bpf_timer *)(dst + map->timer_off) =
      (struct bpf_timer){};
can help generate bpf_timer definition in vmlinuxBTF.
But the code above may not zero the whole structure
due to anonymour members and that code will be replaced
by memset in the subsequent patch and
bpf_timer definition will disappear from vmlinuxBTF.
Let us emit the type explicitly so bpf program can continue
to use it from vmlinux.h.
Signed-off-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220211194948.3141529-1-yhs@fb.com
      3bd916ee
    • Alexei Starovoitov's avatar
      Merge branch 'Fix for crash due to overwrite in copy_map_value' · acc3c473
      Alexei Starovoitov authored 
      Kumar Kartikeya says:

====================

A fix for an oversight in copy_map_value that leads to kernel crash.

Also, a question for BPF developers:
It seems in arraymap.c, we always do check_and_free_timer_in_array after we do
copy_map_value in map_update_elem callback, but the same is not done for
hashtab.c. Is there a specific reason for this difference in behavior, or did I
miss that it happens for hashtab.c as well?

Changlog:
---------
v1 -> v2:
v1: https://lore.kernel.org/bpf/20220209051113.870717-1-memxor@gmail.com

 * Fix build error for selftests patch due to missing SYS_PREFIX in bpf tree
====================
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
      acc3c473
    • Kumar Kartikeya Dwivedi's avatar
      selftests/bpf: Add test for bpf_timer overwriting crash · a7e75016
      Kumar Kartikeya Dwivedi authored 
      Add a test that validates that timer value is not overwritten when doing
a copy_map_value call in the kernel. Without the prior fix, this test
triggers a crash.
Signed-off-by: default avatarKumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220209070324.1093182-3-memxor@gmail.com
      a7e75016
    • Kumar Kartikeya Dwivedi's avatar
      bpf: Fix crash due to incorrect copy_map_value · a8abb0c3
      Kumar Kartikeya Dwivedi authored 
      When both bpf_spin_lock and bpf_timer are present in a BPF map value,
copy_map_value needs to skirt both objects when copying a value into and
out of the map. However, the current code does not set both s_off and
t_off in copy_map_value, which leads to a crash when e.g. bpf_spin_lock
is placed in map value with bpf_timer, as bpf_map_update_elem call will
be able to overwrite the other timer object.

When the issue is not fixed, an overwriting can produce the following
splat:

[root@(none) bpf]# ./test_progs -t timer_crash
[   15.930339] bpf_testmod: loading out-of-tree module taints kernel.
[   16.037849] ==================================================================
[   16.038458] BUG: KASAN: user-memory-access in __pv_queued_spin_lock_slowpath+0x32b/0x520
[   16.038944] Write of size 8 at addr 0000000000043ec0 by task test_progs/325
[   16.039399]
[   16.039514] CPU: 0 PID: 325 Comm: test_progs Tainted: G           OE     5.16.0+ #278
[   16.039983] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ArchLinux 1.15.0-1 04/01/2014
[   16.040485] Call Trace:
[   16.040645]  <TASK>
[   16.040805]  dump_stack_lvl+0x59/0x73
[   16.041069]  ? __pv_queued_spin_lock_slowpath+0x32b/0x520
[   16.041427]  kasan_report.cold+0x116/0x11b
[   16.041673]  ? __pv_queued_spin_lock_slowpath+0x32b/0x520
[   16.042040]  __pv_queued_spin_lock_slowpath+0x32b/0x520
[   16.042328]  ? memcpy+0x39/0x60
[   16.042552]  ? pv_hash+0xd0/0xd0
[   16.042785]  ? lockdep_hardirqs_off+0x95/0xd0
[   16.043079]  __bpf_spin_lock_irqsave+0xdf/0xf0
[   16.043366]  ? bpf_get_current_comm+0x50/0x50
[   16.043608]  ? jhash+0x11a/0x270
[   16.043848]  bpf_timer_cancel+0x34/0xe0
[   16.044119]  bpf_prog_c4ea1c0f7449940d_sys_enter+0x7c/0x81
[   16.044500]  bpf_trampoline_6442477838_0+0x36/0x1000
[   16.044836]  __x64_sys_nanosleep+0x5/0x140
[   16.045119]  do_syscall_64+0x59/0x80
[   16.045377]  ? lock_is_held_type+0xe4/0x140
[   16.045670]  ? irqentry_exit_to_user_mode+0xa/0x40
[   16.046001]  ? mark_held_locks+0x24/0x90
[   16.046287]  ? asm_exc_page_fault+0x1e/0x30
[   16.046569]  ? asm_exc_page_fault+0x8/0x30
[   16.046851]  ? lockdep_hardirqs_on+0x7e/0x100
[   16.047137]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[   16.047405] RIP: 0033:0x7f9e4831718d
[   16.047602] Code: b4 0c 00 0f 05 eb a9 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d b3 6c 0c 00 f7 d8 64 89 01 48
[   16.048764] RSP: 002b:00007fff488086b8 EFLAGS: 00000206 ORIG_RAX: 0000000000000023
[   16.049275] RAX: ffffffffffffffda RBX: 00007f9e48683740 RCX: 00007f9e4831718d
[   16.049747] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007fff488086d0
[   16.050225] RBP: 00007fff488086f0 R08: 00007fff488085d7 R09: 00007f9e4cb594a0
[   16.050648] R10: 0000000000000000 R11: 0000000000000206 R12: 00007f9e484cde30
[   16.051124] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[   16.051608]  </TASK>
[   16.051762] ==================================================================

Fixes: 68134668 ("bpf: Add map side support for bpf timers.")
Signed-off-by: default avatarKumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220209070324.1093182-2-memxor@gmail.com
      a8abb0c3
    • Felix Maurer's avatar
      bpf: Do not try bpf_msg_push_data with len 0 · 4a11678f
      Felix Maurer authored 
      If bpf_msg_push_data() is called with len 0 (as it happens during
selftests/bpf/test_sockmap), we do not need to do anything and can
return early.

Calling bpf_msg_push_data() with len 0 previously lead to a wrong ENOMEM
error: we later called get_order(copy + len); if len was 0, copy + len
was also often 0 and get_order() returned some undefined value (at the
moment 52). alloc_pages() caught that and failed, but then bpf_msg_push_data()
returned ENOMEM. This was wrong because we are most probably not out of
memory and actually do not need any additional memory.

Fixes: 6fff607e ("bpf: sk_msg program helper bpf_msg_push_data")
Signed-off-by: default avatarFelix Maurer <fmaurer@redhat.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Acked-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/df69012695c7094ccb1943ca02b4920db3537466.1644421921.git.fmaurer@redhat.com
      4a11678f
    • David S. Miller's avatar
      Merge ra.kernel.org:/pub/scm/linux/kernel/git/netfilter/nf · 525de9a7
      David S. Miller authored 
      Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

1) Add selftest for nft_synproxy, from Florian Westphal.

2) xt_socket destroy path incorrectly disables IPv4 defrag for
   IPv6 traffic (typo), from Eric Dumazet.

3) Fix exit value selftest nft_concat_range.sh, from Hangbin Liu.

4) nft_synproxy disables the IPv4 hooks if the IPv6 hooks fail
   to be registered.

5) disable rp_filter on router in selftest nft_fib.sh, also
   from Hangbin Liu.
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      525de9a7
    • Eric Dumazet's avatar
      drop_monitor: fix data-race in dropmon_net_event / trace_napi_poll_hit · dcd54265
      Eric Dumazet authored 
      trace_napi_poll_hit() is reading stat->dev while another thread can write
on it from dropmon_net_event()

Use READ_ONCE()/WRITE_ONCE() here, RCU rules are properly enforced already,
we only have to take care of load/store tearing.

BUG: KCSAN: data-race in dropmon_net_event / trace_napi_poll_hit

write to 0xffff88816f3ab9c0 of 8 bytes by task 20260 on cpu 1:
 dropmon_net_event+0xb8/0x2b0 net/core/drop_monitor.c:1579
 notifier_call_chain kernel/notifier.c:84 [inline]
 raw_notifier_call_chain+0x53/0xb0 kernel/notifier.c:392
 call_netdevice_notifiers_info net/core/dev.c:1919 [inline]
 call_netdevice_notifiers_extack net/core/dev.c:1931 [inline]
 call_netdevice_notifiers net/core/dev.c:1945 [inline]
 unregister_netdevice_many+0x867/0xfb0 net/core/dev.c:10415
 ip_tunnel_delete_nets+0x24a/0x280 net/ipv4/ip_tunnel.c:1123
 vti_exit_batch_net+0x2a/0x30 net/ipv4/ip_vti.c:515
 ops_exit_list net/core/net_namespace.c:173 [inline]
 cleanup_net+0x4dc/0x8d0 net/core/net_namespace.c:597
 process_one_work+0x3f6/0x960 kernel/workqueue.c:2307
 worker_thread+0x616/0xa70 kernel/workqueue.c:2454
 kthread+0x1bf/0x1e0 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30

read to 0xffff88816f3ab9c0 of 8 bytes by interrupt on cpu 0:
 trace_napi_poll_hit+0x89/0x1c0 net/core/drop_monitor.c:292
 trace_napi_poll include/trace/events/napi.h:14 [inline]
 __napi_poll+0x36b/0x3f0 net/core/dev.c:6366
 napi_poll net/core/dev.c:6432 [inline]
 net_rx_action+0x29e/0x650 net/core/dev.c:6519
 __do_softirq+0x158/0x2de kernel/softirq.c:558
 do_softirq+0xb1/0xf0 kernel/softirq.c:459
 __local_bh_enable_ip+0x68/0x70 kernel/softirq.c:383
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
 _raw_spin_unlock_bh+0x33/0x40 kernel/locking/spinlock.c:210
 spin_unlock_bh include/linux/spinlock.h:394 [inline]
 ptr_ring_consume_bh include/linux/ptr_ring.h:367 [inline]
 wg_packet_decrypt_worker+0x73c/0x780 drivers/net/wireguard/receive.c:506
 process_one_work+0x3f6/0x960 kernel/workqueue.c:2307
 worker_thread+0x616/0xa70 kernel/workqueue.c:2454
 kthread+0x1bf/0x1e0 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30

value changed: 0xffff88815883e000 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 26435 Comm: kworker/0:1 Not tainted 5.17.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: wg-crypt-wg2 wg_packet_decrypt_worker

Fixes: 4ea7e386 ("dropmon: add ability to detect when hardware dropsrxpackets")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      dcd54265
    • Wen Gu's avatar
      net/smc: Avoid overwriting the copies of clcsock callback functions · 1de9770d
      Wen Gu authored 
      The callback functions of clcsock will be saved and replaced during
the fallback. But if the fallback happens more than once, then the
copies of these callback functions will be overwritten incorrectly,
resulting in a loop call issue:

clcsk->sk_error_report
 |- smc_fback_error_report() <------------------------------|
     |- smc_fback_forward_wakeup()                          | (loop)
         |- clcsock_callback()  (incorrectly overwritten)   |
             |- smc->clcsk_error_report() ------------------|

So this patch fixes the issue by saving these function pointers only
once in the fallback and avoiding overwriting.

Reported-by: syzbot+4de3c0e8a263e1e499bc@syzkaller.appspotmail.com
Fixes: 341adeec ("net/smc: Forward wakeup to smc socket waitqueue after fallback")
Link: https://lore.kernel.org/r/0000000000006d045e05d78776f6@google.comSigned-off-by: default avatarWen Gu <guwen@linux.alibaba.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      1de9770d
    • Linus Torvalds's avatar
      Merge tag 'net-5.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net · f1baf68e
      Linus Torvalds authored 
      Pull networking fixes from Jakub Kicinski:
 "Including fixes from netfilter and can.

Current release - new code bugs:

   - sparx5: fix get_stat64 out-of-bound access and crash

   - smc: fix netdev ref tracker misuse

  Previous releases - regressions:

   - eth: ixgbevf: require large buffers for build_skb on 82599VF, avoid
     overflows

   - eth: ocelot: fix all IP traffic getting trapped to CPU with PTP
     over IP

   - bonding: fix rare link activation misses in 802.3ad mode

  Previous releases - always broken:

   - tcp: fix tcp sock mem accounting in zero-copy corner cases

   - remove the cached dst when uncloning an skb dst and its metadata,
     since we only have one ref it'd lead to an UaF

   - netfilter:
      - conntrack: don't refresh sctp entries in closed state
      - conntrack: re-init state for retransmitted syn-ack, avoid
        connection establishment getting stuck with strange stacks
      - ctnetlink: disable helper autoassign, avoid it getting lost
      - nft_payload: don't allow transport header access for fragments

   - dsa: fix use of devres for mdio throughout drivers

   - eth: amd-xgbe: disable interrupts during pci removal

   - eth: dpaa2-eth: unregister netdev before disconnecting the PHY

   - eth: ice: fix IPIP and SIT TSO offload"

* tag 'net-5.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (53 commits)
  net: dsa: mv88e6xxx: fix use-after-free in mv88e6xxx_mdios_unregister
  net: mscc: ocelot: fix mutex lock error during ethtool stats read
  ice: Avoid RTNL lock when re-creating auxiliary device
  ice: Fix KASAN error in LAG NETDEV_UNREGISTER handler
  ice: fix IPIP and SIT TSO offload
  ice: fix an error code in ice_cfg_phy_fec()
  net: mpls: Fix GCC 12 warning
  dpaa2-eth: unregister the netdev before disconnecting from the PHY
  skbuff: cleanup double word in comment
  net: macb: Align the dma and coherent dma masks
  mptcp: netlink: process IPv6 addrs in creating listening sockets
  selftests: mptcp: add missing join check
  net: usb: qmi_wwan: Add support for Dell DW5829e
  vlan: move dev_put into vlan_dev_uninit
  vlan: introduce vlan_dev_free_egress_priority
  ax25: fix UAF bugs of net_device caused by rebinding operation
  net: dsa: fix panic when DSA master device unbinds on shutdown
  net: amd-xgbe: disable interrupts during pci removal
  tipc: rate limit warning for received illegal binding update
  net: mdio: aspeed: Add missing MODULE_DEVICE_TABLE
  ...
      f1baf68e
  9. 10 Feb, 2022 23 commits
  11. 09 Feb, 2022 3 commits
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