1. 11 2月, 2014 6 次提交
    • T
      bridge: Properly check if local fdb entry can be deleted in br_fdb_change_mac_address · 960b589f
      Toshiaki Makita 提交于
      br_fdb_change_mac_address() doesn't check if the local entry has the
      same address as any of bridge ports.
      Although I'm not sure when it is beneficial, current implementation allow
      the bridge device to receive any mac address of its ports.
      To preserve this behavior, we have to check if the mac address of the
      entry being deleted is identical to that of any port.
      
      As this check is almost the same as that in br_fdb_changeaddr(), create
      a common function fdb_delete_local() and call it from
      br_fdb_changeadddr() and br_fdb_change_mac_address().
      Signed-off-by: NToshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
      Acked-by: NVlad Yasevich <vyasevic@redhat.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      960b589f
    • T
      bridge: Fix the way to check if a local fdb entry can be deleted · 2b292fb4
      Toshiaki Makita 提交于
      We should take into account the followings when deleting a local fdb
      entry.
      
      - nbp_vlan_find() can be used only when vid != 0 to check if an entry is
        deletable, because a fdb entry with vid 0 can exist at any time while
        nbp_vlan_find() always return false with vid 0.
      
        Example of problematic case:
          ip link set eth0 address 12:34:56:78:90:ab
          ip link set eth1 address 12:34:56:78:90:ab
          brctl addif br0 eth0
          brctl addif br0 eth1
          ip link set eth0 address aa:bb:cc:dd:ee:ff
        Then, the fdb entry 12:34:56:78:90:ab will be deleted even though the
        bridge port eth1 still has that address.
      
      - The port to which the bridge device is attached might needs a local entry
        if its mac address is set manually.
      
        Example of problematic case:
          ip link set eth0 address 12:34:56:78:90:ab
          brctl addif br0 eth0
          ip link set br0 address 12:34:56:78:90:ab
          ip link set eth0 address aa:bb:cc:dd:ee:ff
        Then, the fdb still must have the entry 12:34:56:78:90:ab, but it will be
        deleted.
      
      We can use br->dev->addr_assign_type to check if the address is manually
      set or not, but I propose another approach.
      
      Since we delete and insert local entries whenever changing mac address
      of the bridge device, we can change dst of the entry to NULL regardless of
      addr_assign_type when deleting an entry associated with a certain port,
      and if it is found to be unnecessary later, then delete it.
      That is, if changing mac address of a port, the entry might be changed
      to its dst being NULL first, but is eventually deleted when recalculating
      and changing bridge id.
      
      This approach is especially useful when we want to share the code with
      deleting vlan in which the bridge device might want such an entry regardless
      of addr_assign_type, and makes things easy because we don't have to consider
      if mac address of the bridge device will be changed or not at the time we
      delete a local entry of a port, which means fdb code will not be bothered
      even if the bridge id calculating logic is changed in the future.
      
      Also, this change reduces inconsistent state, where frames whose dst is the
      mac address of the bridge, can't reach the bridge because of premature fdb
      entry deletion. This change reduces the possibility that the bridge device
      replies unreachable mac address to arp requests, which could occur during
      the short window between calling del_nbp() and br_stp_recalculate_bridge_id()
      in br_del_if(). This will effective after br_fdb_delete_by_port() starts to
      use the same code by following patch.
      Signed-off-by: NToshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
      Acked-by: NVlad Yasevich <vyasevic@redhat.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2b292fb4
    • T
      bridge: Change local fdb entries whenever mac address of bridge device changes · a4b816d8
      Toshiaki Makita 提交于
      Vlan code may need fdb change when changing mac address of bridge device
      even if it is caused by the mac address changing of a bridge port.
      
      Example configuration:
        ip link set eth0 address 12:34:56:78:90:ab
        ip link set eth1 address aa:bb:cc:dd:ee:ff
        brctl addif br0 eth0
        brctl addif br0 eth1 # br0 will have mac address 12:34:56:78:90:ab
        bridge vlan add dev br0 vid 10 self
        bridge vlan add dev eth0 vid 10
      We will have fdb entry such that f->dst == NULL, f->vlan_id == 10 and
      f->addr == 12:34:56:78:90:ab at this time.
      Next, change the mac address of eth0 to greater value.
        ip link set eth0 address ee:ff:12:34:56:78
      Then, mac address of br0 will be recalculated and set to aa:bb:cc:dd:ee:ff.
      However, an entry aa:bb:cc:dd:ee:ff will not be created and we will be not
      able to communicate using br0 on vlan 10.
      
      Address this issue by deleting and adding local entries whenever
      changing the mac address of the bridge device.
      
      If there already exists an entry that has the same address, for example,
      in case that br_fdb_changeaddr() has already inserted it,
      br_fdb_change_mac_address() will simply fail to insert it and no
      duplicated entry will be made, as it was.
      
      This approach also needs br_add_if() to call br_fdb_insert() before
      br_stp_recalculate_bridge_id() so that we don't create an entry whose
      dst == NULL in this function to preserve previous behavior.
      
      Note that this is a slight change in behavior where the bridge device can
      receive the traffic to the new address before calling
      br_stp_recalculate_bridge_id() in br_add_if().
      However, it is not a problem because we have already the address on the
      new port and such a way to insert new one before recalculating bridge id
      is taken in br_device_event() as well.
      Signed-off-by: NToshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
      Acked-by: NVlad Yasevich <vyasevic@redhat.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a4b816d8
    • T
      bridge: Fix the way to find old local fdb entries in br_fdb_change_mac_address · a3ebb7ef
      Toshiaki Makita 提交于
      We have been always failed to delete the old entry at
      br_fdb_change_mac_address() because br_set_mac_address() updates
      dev->dev_addr before calling br_fdb_change_mac_address() and
      br_fdb_change_mac_address() uses dev->dev_addr to find the old entry.
      
      That update of dev_addr is completely unnecessary because the same work
      is done in br_stp_change_bridge_id() which is called right away after
      calling br_fdb_change_mac_address().
      Signed-off-by: NToshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
      Acked-by: NVlad Yasevich <vyasevic@redhat.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a3ebb7ef
    • T
      bridge: Fix the way to insert new local fdb entries in br_fdb_changeaddr · 2836882f
      Toshiaki Makita 提交于
      Since commit bc9a25d2 ("bridge: Add vlan support for local fdb entries"),
      br_fdb_changeaddr() has inserted a new local fdb entry only if it can
      find old one. But if we have two ports where they have the same address
      or user has deleted a local entry, there will be no entry for one of the
      ports.
      
      Example of problematic case:
        ip link set eth0 address aa:bb:cc:dd:ee:ff
        ip link set eth1 address aa:bb:cc:dd:ee:ff
        brctl addif br0 eth0
        brctl addif br0 eth1 # eth1 will not have a local entry due to dup.
        ip link set eth1 address 12:34:56:78:90:ab
      Then, the new entry for the address 12:34:56:78:90:ab will not be
      created, and the bridge device will not be able to communicate.
      
      Insert new entries regardless of whether we can find old entries or not.
      Signed-off-by: NToshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
      Acked-by: NVlad Yasevich <vyasevic@redhat.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2836882f
    • T
      bridge: Fix the way to find old local fdb entries in br_fdb_changeaddr · a5642ab4
      Toshiaki Makita 提交于
      br_fdb_changeaddr() assumes that there is at most one local entry per port
      per vlan. It used to be true, but since commit 36fd2b63 ("bridge: allow
      creating/deleting fdb entries via netlink"), it has not been so.
      Therefore, the function might fail to search a correct previous address
      to be deleted and delete an arbitrary local entry if user has added local
      entries manually.
      
      Example of problematic case:
        ip link set eth0 address ee:ff:12:34:56:78
        brctl addif br0 eth0
        bridge fdb add 12:34:56:78:90:ab dev eth0 master
        ip link set eth0 address aa:bb:cc:dd:ee:ff
      Then, the address 12:34:56:78:90:ab might be deleted instead of
      ee:ff:12:34:56:78, the original mac address of eth0.
      
      Address this issue by introducing a new flag, added_by_user, to struct
      net_bridge_fdb_entry.
      
      Note that br_fdb_delete_by_port() has to set added_by_user to 0 in cases
      like:
        ip link set eth0 address 12:34:56:78:90:ab
        ip link set eth1 address aa:bb:cc:dd:ee:ff
        brctl addif br0 eth0
        bridge fdb add aa:bb:cc:dd:ee:ff dev eth0 master
        brctl addif br0 eth1
        brctl delif br0 eth0
      In this case, kernel should delete the user-added entry aa:bb:cc:dd:ee:ff,
      but it also should have been added by "brctl addif br0 eth1" originally,
      so we don't delete it and treat it a new kernel-created entry.
      Signed-off-by: NToshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a5642ab4
  2. 10 2月, 2014 16 次提交
  3. 08 2月, 2014 2 次提交
  4. 07 2月, 2014 8 次提交
    • P
      netfilter: nft_rbtree: fix data handling of end interval elements · 2fb91ddb
      Pablo Neira Ayuso 提交于
      This patch fixes several things which related to the handling of
      end interval elements:
      
      * Chain use underflow with intervals and map: If you add a rule
        using intervals+map that introduces a loop, the error path of the
        rbtree set decrements the chain refcount for each side of the
        interval, leading to a chain use counter underflow.
      
      * Don't copy the data part of the end interval element since, this
        area is uninitialized and this confuses the loop detection code.
      
      * Don't allocate room for the data part of end interval elements
        since this is unused.
      
      So, after this patch the idea is that end interval elements don't
      have a data part.
      Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
      Acked-by: NPatrick McHardy <kaber@trash.net>
      2fb91ddb
    • P
      netfilter: nf_tables: do not allow NFT_SET_ELEM_INTERVAL_END flag and data · bd7fc645
      Pablo Neira Ayuso 提交于
      This combination is not allowed since end interval elements cannot
      contain data.
      Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
      Acked-by: NPatrick McHardy <kaber@trash.net>
      bd7fc645
    • E
      tcp: remove 1ms offset in srtt computation · 4a5ab4e2
      Eric Dumazet 提交于
      TCP pacing depends on an accurate srtt estimation.
      
      Current srtt estimation is using jiffie resolution,
      and has an artificial offset of at least 1 ms, which can produce
      slowdowns when FQ/pacing is used, especially in DC world,
      where typical rtt is below 1 ms.
      
      We are planning a switch to usec resolution for linux-3.15,
      but in the meantime, this patch removes the 1 ms offset.
      
      All we need is to have tp->srtt minimal value of 1 to differentiate
      the case of srtt being initialized or not, not 8.
      
      The problematic behavior was observed on a 40Gbit testbed,
      where 32 concurrent netperf were reaching 12Gbps of aggregate
      speed, instead of line speed.
      
      This patch also has the effect of reporting more accurate srtt and send
      rates to iproute2 ss command as in :
      
      $ ss -i dst cca2
      Netid  State      Recv-Q Send-Q          Local Address:Port
      Peer Address:Port
      tcp    ESTAB      0      0                10.244.129.1:56984
      10.244.129.2:12865
      	 cubic wscale:6,6 rto:200 rtt:0.25/0.25 ato:40 mss:1448 cwnd:10 send
      463.4Mbps rcv_rtt:1 rcv_space:29200
      tcp    ESTAB      0      390960           10.244.129.1:60247
      10.244.129.2:50204
      	 cubic wscale:6,6 rto:200 rtt:0.875/0.75 mss:1448 cwnd:73 ssthresh:51
      send 966.4Mbps unacked:73 retrans:0/121 rcv_space:29200
      Reported-by: NVytautas Valancius <valas@google.com>
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Cc: Yuchung Cheng <ycheng@google.com>
      Cc: Neal Cardwell <ncardwell@google.com>
      Acked-by: NNeal Cardwell <ncardwell@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      4a5ab4e2
    • C
      bridge: fix netconsole setup over bridge · dbe17307
      Cong Wang 提交于
      Commit 93d8bf9f ("bridge: cleanup netpoll code") introduced
      a check in br_netpoll_enable(), but this check is incorrect for
      br_netpoll_setup(). This patch moves the code after the check
      into __br_netpoll_enable() and calls it in br_netpoll_setup().
      For br_add_if(), the check is still needed.
      
      Fixes: 93d8bf9f ("bridge: cleanup netpoll code")
      Cc: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
      Cc: Stephen Hemminger <stephen@networkplumber.org>
      Cc: David S. Miller <davem@davemloft.net>
      Signed-off-by: NCong Wang <cwang@twopensource.com>
      Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
      Acked-by: NToshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
      Tested-by: NToshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      dbe17307
    • E
      net: use __GFP_NORETRY for high order allocations · ed98df33
      Eric Dumazet 提交于
      sock_alloc_send_pskb() & sk_page_frag_refill()
      have a loop trying high order allocations to prepare
      skb with low number of fragments as this increases performance.
      
      Problem is that under memory pressure/fragmentation, this can
      trigger OOM while the intent was only to try the high order
      allocations, then fallback to order-0 allocations.
      
      We had various reports from unexpected regressions.
      
      According to David, setting __GFP_NORETRY should be fine,
      as the asynchronous compaction is still enabled, and this
      will prevent OOM from kicking as in :
      
      CFSClientEventm invoked oom-killer: gfp_mask=0x42d0, order=3, oom_adj=0,
      oom_score_adj=0, oom_score_badness=2 (enabled),memcg_scoring=disabled
      CFSClientEventm
      
      Call Trace:
       [<ffffffff8043766c>] dump_header+0xe1/0x23e
       [<ffffffff80437a02>] oom_kill_process+0x6a/0x323
       [<ffffffff80438443>] out_of_memory+0x4b3/0x50d
       [<ffffffff8043a4a6>] __alloc_pages_may_oom+0xa2/0xc7
       [<ffffffff80236f42>] __alloc_pages_nodemask+0x1002/0x17f0
       [<ffffffff8024bd23>] alloc_pages_current+0x103/0x2b0
       [<ffffffff8028567f>] sk_page_frag_refill+0x8f/0x160
       [<ffffffff80295fa0>] tcp_sendmsg+0x560/0xee0
       [<ffffffff802a5037>] inet_sendmsg+0x67/0x100
       [<ffffffff80283c9c>] __sock_sendmsg_nosec+0x6c/0x90
       [<ffffffff80283e85>] sock_sendmsg+0xc5/0xf0
       [<ffffffff802847b6>] __sys_sendmsg+0x136/0x430
       [<ffffffff80284ec8>] sys_sendmsg+0x88/0x110
       [<ffffffff80711472>] system_call_fastpath+0x16/0x1b
      Out of Memory: Kill process 2856 (bash) score 9999 or sacrifice child
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Acked-by: NDavid Rientjes <rientjes@google.com>
      Acked-by: N"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      ed98df33
    • S
      netpoll: fix netconsole IPv6 setup · 00fe11b3
      Sabrina Dubroca 提交于
      Currently, to make netconsole start over IPv6, the source address
      needs to be specified. Without a source address, netpoll_parse_options
      assumes we're setting up over IPv4 and the destination IPv6 address is
      rejected.
      
      Check if the IP version has been forced by a source address before
      checking for a version mismatch when parsing the destination address.
      Signed-off-by: NSabrina Dubroca <sd@queasysnail.net>
      Acked-by: NCong Wang <cwang@twopensource.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      00fe11b3
    • M
      net: sctp: fix initialization of local source address on accepted ipv6 sockets · 661dbf34
      Matija Glavinic Pecotic 提交于
      commit 	efe4208f:
      'ipv6: make lookups simpler and faster' broke initialization of local source
      address on accepted ipv6 sockets. Before the mentioned commit receive address
      was copied along with the contents of ipv6_pinfo in sctp_v6_create_accept_sk.
      Now when it is moved, it has to be copied separately.
      
      This also fixes lksctp's ipv6 regression in a sense that test_getname_v6, TC5 -
      'getsockname on a connected server socket' now passes.
      Signed-off-by: NMatija Glavinic Pecotic <matija.glavinic-pecotic.ext@nsn.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      661dbf34
    • G
      ipv4: Fix runtime WARNING in rtmsg_ifa() · 63b5f152
      Geert Uytterhoeven 提交于
      On m68k/ARAnyM:
      
      WARNING: CPU: 0 PID: 407 at net/ipv4/devinet.c:1599 0x316a99()
      Modules linked in:
      CPU: 0 PID: 407 Comm: ifconfig Not tainted
      3.13.0-atari-09263-g0c71d68014d1 #1378
      Stack from 10c4fdf0:
              10c4fdf0 002ffabb 000243e8 00000000 008ced6c 00024416 00316a99 0000063f
              00316a99 00000009 00000000 002501b4 00316a99 0000063f c0a86117 00000080
              c0a86117 00ad0c90 00250a5a 00000014 00ad0c90 00000000 00000000 00000001
              00b02dd0 00356594 00000000 00356594 c0a86117 eff6c9e4 008ced6c 00000002
              008ced60 0024f9b4 00250b52 00ad0c90 00000000 00000000 00252390 00ad0c90
              eff6c9e4 0000004f 00000000 00000000 eff6c9e4 8000e25c eff6c9e4 80001020
      Call Trace: [<000243e8>] warn_slowpath_common+0x52/0x6c
       [<00024416>] warn_slowpath_null+0x14/0x1a
       [<002501b4>] rtmsg_ifa+0xdc/0xf0
       [<00250a5a>] __inet_insert_ifa+0xd6/0x1c2
       [<0024f9b4>] inet_abc_len+0x0/0x42
       [<00250b52>] inet_insert_ifa+0xc/0x12
       [<00252390>] devinet_ioctl+0x2ae/0x5d6
      
      Adding some debugging code reveals that net_fill_ifaddr() fails in
      
          put_cacheinfo(skb, ifa->ifa_cstamp, ifa->ifa_tstamp,
                                    preferred, valid))
      
      nla_put complains:
      
          lib/nlattr.c:454: skb_tailroom(skb) = 12, nla_total_size(attrlen) = 20
      
      Apparently commit 5c766d64 ("ipv4:
      introduce address lifetime") forgot to take into account the addition of
      struct ifa_cacheinfo in inet_nlmsg_size(). Hence add it, like is already
      done for ipv6.
      Suggested-by: NCong Wang <cwang@twopensource.com>
      Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
      Signed-off-by: NCong Wang <cwang@twopensource.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      63b5f152
  5. 06 2月, 2014 8 次提交
    • P
      netfilter: nf_tables: fix racy rule deletion · 0165d932
      Pablo Neira Ayuso 提交于
      We may lost race if we flush the rule-set (which happens asynchronously
      via call_rcu) and we try to remove the table (that userspace assumes
      to be empty).
      
      Fix this by recovering synchronous rule and chain deletion. This was
      introduced time ago before we had no batch support, and synchronous
      rule deletion performance was not good. Now that we have the batch
      support, we can just postpone the purge of old rule in a second step
      in the commit phase. All object deletions are synchronous after this
      patch.
      
      As a side effect, we save memory as we don't need rcu_head per rule
      anymore.
      
      Cc: Patrick McHardy <kaber@trash.net>
      Reported-by: NArturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
      Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
      0165d932
    • P
      netfilter: nf_tables: fix log/queue expressions for NFPROTO_INET · b8ecbee6
      Patrick McHardy 提交于
      The log and queue expressions both store the family during ->init() and
      use it to deliver packets. This is wrong when used in NFPROTO_INET since
      they should both deliver to the actual AF of the packet, not the dummy
      NFPROTO_INET.
      
      Use the family from the hook ops to fix this.
      Signed-off-by: NPatrick McHardy <kaber@trash.net>
      Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
      b8ecbee6
    • J
      mac80211: fix virtual monitor interface iteration · fab57a6c
      Johannes Berg 提交于
      During channel context assignment, the interface should
      be found by interface iteration, so we need to assign the
      pointer before the channel context.
      Reported-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
      Tested-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
      Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
      fab57a6c
    • J
      mac80211: fix fragmentation code, particularly for encryption · 338f977f
      Johannes Berg 提交于
      The "new" fragmentation code (since my rewrite almost 5 years ago)
      erroneously sets skb->len rather than using skb_trim() to adjust
      the length of the first fragment after copying out all the others.
      This leaves the skb tail pointer pointing to after where the data
      originally ended, and thus causes the encryption MIC to be written
      at that point, rather than where it belongs: immediately after the
      data.
      
      The impact of this is that if software encryption is done, then
       a) encryption doesn't work for the first fragment, the connection
          becomes unusable as the first fragment will never be properly
          verified at the receiver, the MIC is practically guaranteed to
          be wrong
       b) we leak up to 8 bytes of plaintext (!) of the packet out into
          the air
      
      This is only mitigated by the fact that many devices are capable
      of doing encryption in hardware, in which case this can't happen
      as the tail pointer is irrelevant in that case. Additionally,
      fragmentation is not used very frequently and would normally have
      to be configured manually.
      
      Fix this by using skb_trim() properly.
      
      Cc: stable@vger.kernel.org
      Fixes: 2de8e0d9 ("mac80211: rewrite fragmentation")
      Reported-by: NJouni Malinen <j@w1.fi>
      Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
      338f977f
    • S
      mac80211: Fix IBSS disconnect · d4c80d9d
      Sujith Manoharan 提交于
      Currently, when a station leaves an IBSS network, the
      corresponding BSS is not dropped from cfg80211 if there are
      other active stations in the network. But, the small
      window that is present when trying to determine a station's
      status based on IEEE80211_IBSS_MERGE_INTERVAL introduces
      a race.
      
      Instead of trying to keep the BSS, always remove it when
      leaving an IBSS network. There is not much benefit to retain
      the BSS entry since it will be added with a subsequent join
      operation.
      
      This fixes an issue where a dangling BSS entry causes ath9k
      to wait for a beacon indefinitely.
      
      Cc: <stable@vger.kernel.org>
      Reported-by: NSimon Wunderlich <sw@simonwunderlich.de>
      Signed-off-by: NSujith Manoharan <c_manoha@qca.qualcomm.com>
      Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
      d4c80d9d
    • E
      mac80211: release the channel in error path in start_ap · 0297ea17
      Emmanuel Grumbach 提交于
      When the driver cannot start the AP or when the assignement
      of the beacon goes wrong, we need to unassign the vif.
      
      Cc: stable@vger.kernel.org
      Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
      Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
      0297ea17
    • J
      cfg80211: send scan results from work queue · f9d15d16
      Johannes Berg 提交于
      Due to the previous commit, when a scan finishes, it is in theory
      possible to hit the following sequence:
       1. interface starts being removed
       2. scan is cancelled by driver and cfg80211 is notified
       3. scan done work is scheduled
       4. interface is removed completely, rdev->scan_req is freed,
          event sent to userspace but scan done work remains pending
       5. new scan is requested on another virtual interface
       6. scan done work runs, freeing the still-running scan
      
      To fix this situation, hang on to the scan done message and block
      new scans while that is the case, and only send the message from
      the work function, regardless of whether the scan_req is already
      freed from interface removal. This makes step 5 above impossible
      and changes step 6 to be
       5. scan done work runs, sending the scan done message
      
      As this can't work for wext, so we send the message immediately,
      but this shouldn't be an issue since we still return -EBUSY.
      Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
      f9d15d16
    • J
      cfg80211: fix scan done race · a617302c
      Johannes Berg 提交于
      When an interface/wdev is removed, any ongoing scan should be
      cancelled by the driver. This will make it call cfg80211, which
      only queues a work struct. If interface/wdev removal is quick
      enough, this can leave the scan request pending and processed
      only after the interface is gone, causing a use-after-free.
      
      Fix this by making sure the scan request is not pending after
      the interface is destroyed. We can't flush or cancel the work
      item due to locking concerns, but when it'll run it shouldn't
      find anything to do. This leaves a potential issue, if a new
      scan gets requested before the work runs, it prematurely stops
      the running scan, potentially causing another crash. I'll fix
      that in the next patch.
      
      This was particularly observed with P2P_DEVICE wdevs, likely
      because freeing them is quicker than freeing netdevs.
      Reported-by: NAndrei Otcheretianski <andrei.otcheretianski@intel.com>
      Fixes: 4a58e7c3 ("cfg80211: don't "leak" uncompleted scans")
      Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
      a617302c