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  1. Dec 18, 2021
    • George Kennedy's avatar
      tun: avoid double free in tun_free_netdev · 158b515f
      George Kennedy authored 
      
Avoid double free in tun_free_netdev() by moving the
dev->tstats and tun->security allocs to a new ndo_init routine
(tun_net_init()) that will be called by register_netdevice().
ndo_init is paired with the desctructor (tun_free_netdev()),
so if there's an error in register_netdevice() the destructor
will handle the frees.

BUG: KASAN: double-free or invalid-free in selinux_tun_dev_free_security+0x1a/0x20 security/selinux/hooks.c:5605

CPU: 0 PID: 25750 Comm: syz-executor416 Not tainted 5.16.0-rc2-syzk #1
Hardware name: Red Hat KVM, BIOS
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x89/0xb5 lib/dump_stack.c:106
print_address_description.constprop.9+0x28/0x160 mm/kasan/report.c:247
kasan_report_invalid_free+0x55/0x80 mm/kasan/report.c:372
____kasan_slab_free mm/kasan/common.c:346 [inline]
__kasan_slab_free+0x107/0x120 mm/kasan/common.c:374
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:1723 [inline]
slab_free_freelist_hook mm/slub.c:1749 [inline]
slab_free mm/slub.c:3513 [inline]
kfree+0xac/0x2d0 mm/slub.c:4561
selinux_tun_dev_free_security+0x1a/0x20 security/selinux/hooks.c:5605
security_tun_dev_free_security+0x4f/0x90 security/security.c:2342
tun_free_netdev+0xe6/0x150 drivers/net/tun.c:2215
netdev_run_todo+0x4df/0x840 net/core/dev.c:10627
rtnl_unlock+0x13/0x20 net/core/rtnetlink.c:112
__tun_chr_ioctl+0x80c/0x2870 drivers/net/tun.c:3302
tun_chr_ioctl+0x2f/0x40 drivers/net/tun.c:3311
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__x64_sys_ioctl+0x19d/0x220 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3a/0x80 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported-by: default avatarsyzkaller <syzkaller@googlegroups.com>
Signed-off-by: default avatarGeorge Kennedy <george.kennedy@oracle.com>
Suggested-by: default avatarJakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/1639679132-19884-1-git-send-email-george.kennedy@oracle.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      158b515f
  3. Nov 15, 2021
  5. Aug 24, 2021
  7. May 19, 2021
  9. Apr 28, 2021
  11. Apr 06, 2021
  13. Mar 18, 2021
  15. Feb 12, 2021
    • Cong Wang's avatar
      net: fix dev_ifsioc_locked() race condition · 3b23a32a
      Cong Wang authored 
      
dev_ifsioc_locked() is called with only RCU read lock, so when
there is a parallel writer changing the mac address, it could
get a partially updated mac address, as shown below:

Thread 1			Thread 2
// eth_commit_mac_addr_change()
memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
				// dev_ifsioc_locked()
				memcpy(ifr->ifr_hwaddr.sa_data,
					dev->dev_addr,...);

Close this race condition by guarding them with a RW semaphore,
like netdev_get_name(). We can not use seqlock here as it does not
allow blocking. The writers already take RTNL anyway, so this does
not affect the slow path. To avoid bothering existing
dev_set_mac_address() callers in drivers, introduce a new wrapper
just for user-facing callers on ioctl and rtnetlink paths.

Note, bonding also changes slave mac addresses but that requires
a separate patch due to the complexity of bonding code.

Fixes: 3710becf ("net: RCU locking for simple ioctl()")
Reported-by: default avatar"Gong, Sishuai" <sishuai@purdue.edu>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarCong Wang <cong.wang@bytedance.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      3b23a32a
  17. Jan 20, 2021
  19. Jan 08, 2021
  21. Dec 28, 2020
  23. Nov 30, 2020
  25. Nov 23, 2020
  27. Nov 21, 2020
  29. Nov 10, 2020
  31. Aug 23, 2020
  33. Aug 19, 2020
  35. Aug 01, 2020
    • Jason Wang's avatar
      tun: add missing rcu annotation in tun_set_ebpf() · 8f3f330d
      Jason Wang authored 
      
We expecte prog_p to be protected by rcu, so adding the rcu annotation
to fix the following sparse warning:

drivers/net/tun.c:3003:36: warning: incorrect type in argument 2 (different address spaces)
drivers/net/tun.c:3003:36:    expected struct tun_prog [noderef] __rcu **prog_p
drivers/net/tun.c:3003:36:    got struct tun_prog **prog_p
drivers/net/tun.c:3292:42: warning: incorrect type in argument 2 (different address spaces)
drivers/net/tun.c:3292:42:    expected struct tun_prog **prog_p
drivers/net/tun.c:3292:42:    got struct tun_prog [noderef] __rcu **
drivers/net/tun.c:3296:42: warning: incorrect type in argument 2 (different address spaces)
drivers/net/tun.c:3296:42:    expected struct tun_prog **prog_p
drivers/net/tun.c:3296:42:    got struct tun_prog [noderef] __rcu **

Reported-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      8f3f330d
  37. Jul 26, 2020
  39. Jun 30, 2020
    • Jason A. Donenfeld's avatar
      tun: implement header_ops->parse_protocol for AF_PACKET · b9815eb1
      Jason A. Donenfeld authored 
      
The tun driver passes up skb->protocol to userspace in the form of PI headers.
For AF_PACKET injection, we need to support its call chain of:

    packet_sendmsg -> packet_snd -> packet_parse_headers ->
      dev_parse_header_protocol -> parse_protocol

Without a valid parse_protocol, this returns zero, and the tun driver
then gives userspace bogus values that it can't deal with.

Note that this isn't the case with tap, because tap already benefits
from the shared infrastructure for ethernet headers. But with tun,
there's nothing.

Signed-off-by: default avatarJason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      b9815eb1
  41. Jun 01, 2020
  43. May 15, 2020
  45. Apr 13, 2020
  47. Apr 06, 2020
  49. Mar 07, 2020
  51. Mar 06, 2020
  53. Feb 24, 2020
  55. Jan 23, 2020
    • Eric Dumazet's avatar
      tun: add mutex_unlock() call and napi.skb clearing in tun_get_user() · 1efba987
      Eric Dumazet authored 
      
If both IFF_NAPI_FRAGS mode and XDP are enabled, and the XDP program
consumes the skb, we need to clear the napi.skb (or risk
a use-after-free) and release the mutex (or risk a deadlock)

WARNING: lock held when returning to user space!
5.5.0-rc6-syzkaller #0 Not tainted
------------------------------------------------
syz-executor.0/455 is leaving the kernel with locks still held!
1 lock held by syz-executor.0/455:
 #0: ffff888098f6e748 (&tfile->napi_mutex){+.+.}, at: tun_get_user+0x1604/0x3fc0 drivers/net/tun.c:1835

Fixes: 90e33d45 ("tun: enable napi_gro_frags() for TUN/TAP driver")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
Cc: Petar Penkov <ppenkov@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      1efba987
  57. Jan 17, 2020
    • Toke Høiland-Jørgensen's avatar
      xdp: Use bulking for non-map XDP_REDIRECT and consolidate code paths · 1d233886
      Toke Høiland-Jørgensen authored 
      
Since the bulk queue used by XDP_REDIRECT now lives in struct net_device,
we can re-use the bulking for the non-map version of the bpf_redirect()
helper. This is a simple matter of having xdp_do_redirect_slow() queue the
frame on the bulk queue instead of sending it out with __bpf_tx_xdp().

Unfortunately we can't make the bpf_redirect() helper return an error if
the ifindex doesn't exit (as bpf_redirect_map() does), because we don't
have a reference to the network namespace of the ingress device at the time
the helper is called. So we have to leave it as-is and keep the device
lookup in xdp_do_redirect_slow().

Since this leaves less reason to have the non-map redirect code in a
separate function, so we get rid of the xdp_do_redirect_slow() function
entirely. This does lose us the tracepoint disambiguation, but fortunately
the xdp_redirect and xdp_redirect_map tracepoints use the same tracepoint
entry structures. This means both can contain a map index, so we can just
amend the tracepoint definitions so we always emit the xdp_redirect(_err)
tracepoints, but with the map ID only populated if a map is present. This
means we retire the xdp_redirect_map(_err) tracepoints entirely, but keep
the definitions around in case someone is still listening for them.

With this change, the performance of the xdp_redirect sample program goes
from 5Mpps to 8.4Mpps (a 68% increase).

Since the flush functions are no longer map-specific, rename the flush()
functions to drop _map from their names. One of the renamed functions is
the xdp_do_flush_map() callback used in all the xdp-enabled drivers. To
keep from having to update all drivers, use a #define to keep the old name
working, and only update the virtual drivers in this patch.

Signed-off-by: default avatarToke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/157918768505.1458396.17518057312953572912.stgit@toke.dk
      1d233886
  59. Nov 15, 2019
    • Petar Penkov's avatar
      tun: fix data-race in gro_normal_list() · c39e342a
      Petar Penkov authored 
      
There is a race in the TUN driver between napi_busy_loop and
napi_gro_frags. This commit resolves the race by adding the NAPI struct
via netif_tx_napi_add, instead of netif_napi_add, which disables polling
for the NAPI struct.

KCSAN reported:
BUG: KCSAN: data-race in gro_normal_list.part.0 / napi_busy_loop

write to 0xffff8880b5d474b0 of 4 bytes by task 11205 on cpu 0:
 gro_normal_list.part.0+0x77/0xb0 net/core/dev.c:5682
 gro_normal_list net/core/dev.c:5678 [inline]
 gro_normal_one net/core/dev.c:5692 [inline]
 napi_frags_finish net/core/dev.c:5705 [inline]
 napi_gro_frags+0x625/0x770 net/core/dev.c:5778
 tun_get_user+0x2150/0x26a0 drivers/net/tun.c:1976
 tun_chr_write_iter+0x79/0xd0 drivers/net/tun.c:2022
 call_write_iter include/linux/fs.h:1895 [inline]
 do_iter_readv_writev+0x487/0x5b0 fs/read_write.c:693
 do_iter_write fs/read_write.c:970 [inline]
 do_iter_write+0x13b/0x3c0 fs/read_write.c:951
 vfs_writev+0x118/0x1c0 fs/read_write.c:1015
 do_writev+0xe3/0x250 fs/read_write.c:1058
 __do_sys_writev fs/read_write.c:1131 [inline]
 __se_sys_writev fs/read_write.c:1128 [inline]
 __x64_sys_writev+0x4e/0x60 fs/read_write.c:1128
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880b5d474b0 of 4 bytes by task 11168 on cpu 1:
 gro_normal_list net/core/dev.c:5678 [inline]
 napi_busy_loop+0xda/0x4f0 net/core/dev.c:6126
 sk_busy_loop include/net/busy_poll.h:108 [inline]
 __skb_recv_udp+0x4ad/0x560 net/ipv4/udp.c:1689
 udpv6_recvmsg+0x29e/0xe90 net/ipv6/udp.c:288
 inet6_recvmsg+0xbb/0x240 net/ipv6/af_inet6.c:592
 sock_recvmsg_nosec net/socket.c:871 [inline]
 sock_recvmsg net/socket.c:889 [inline]
 sock_recvmsg+0x92/0xb0 net/socket.c:885
 sock_read_iter+0x15f/0x1e0 net/socket.c:967
 call_read_iter include/linux/fs.h:1889 [inline]
 new_sync_read+0x389/0x4f0 fs/read_write.c:414
 __vfs_read+0xb1/0xc0 fs/read_write.c:427
 vfs_read fs/read_write.c:461 [inline]
 vfs_read+0x143/0x2c0 fs/read_write.c:446
 ksys_read+0xd5/0x1b0 fs/read_write.c:587
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read fs/read_write.c:595 [inline]
 __x64_sys_read+0x4c/0x60 fs/read_write.c:595
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 11168 Comm: syz-executor.0 Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: 94317099 ("tun: enable NAPI for TUN/TAP driver")
Signed-off-by: default avatarPetar Penkov <ppenkov@google.com>
Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      c39e342a