1. 11 1月, 2018 17 次提交
  2. 10 1月, 2018 10 次提交
    • A
      bpf: introduce BPF_JIT_ALWAYS_ON config · 290af866
      Alexei Starovoitov 提交于
      The BPF interpreter has been used as part of the spectre 2 attack CVE-2017-5715.
      
      A quote from goolge project zero blog:
      "At this point, it would normally be necessary to locate gadgets in
      the host kernel code that can be used to actually leak data by reading
      from an attacker-controlled location, shifting and masking the result
      appropriately and then using the result of that as offset to an
      attacker-controlled address for a load. But piecing gadgets together
      and figuring out which ones work in a speculation context seems annoying.
      So instead, we decided to use the eBPF interpreter, which is built into
      the host kernel - while there is no legitimate way to invoke it from inside
      a VM, the presence of the code in the host kernel's text section is sufficient
      to make it usable for the attack, just like with ordinary ROP gadgets."
      
      To make attacker job harder introduce BPF_JIT_ALWAYS_ON config
      option that removes interpreter from the kernel in favor of JIT-only mode.
      So far eBPF JIT is supported by:
      x64, arm64, arm32, sparc64, s390, powerpc64, mips64
      
      The start of JITed program is randomized and code page is marked as read-only.
      In addition "constant blinding" can be turned on with net.core.bpf_jit_harden
      
      v2->v3:
      - move __bpf_prog_ret0 under ifdef (Daniel)
      
      v1->v2:
      - fix init order, test_bpf and cBPF (Daniel's feedback)
      - fix offloaded bpf (Jakub's feedback)
      - add 'return 0' dummy in case something can invoke prog->bpf_func
      - retarget bpf tree. For bpf-next the patch would need one extra hunk.
        It will be sent when the trees are merged back to net-next
      
      Considered doing:
        int bpf_jit_enable __read_mostly = BPF_EBPF_JIT_DEFAULT;
      but it seems better to land the patch as-is and in bpf-next remove
      bpf_jit_enable global variable from all JITs, consolidate in one place
      and remove this jit_init() function.
      Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      290af866
    • D
      bpf: avoid false sharing of map refcount with max_entries · be95a845
      Daniel Borkmann 提交于
      In addition to commit b2157399 ("bpf: prevent out-of-bounds
      speculation") also change the layout of struct bpf_map such that
      false sharing of fast-path members like max_entries is avoided
      when the maps reference counter is altered. Therefore enforce
      them to be placed into separate cachelines.
      
      pahole dump after change:
      
        struct bpf_map {
              const struct bpf_map_ops  * ops;                 /*     0     8 */
              struct bpf_map *           inner_map_meta;       /*     8     8 */
              void *                     security;             /*    16     8 */
              enum bpf_map_type          map_type;             /*    24     4 */
              u32                        key_size;             /*    28     4 */
              u32                        value_size;           /*    32     4 */
              u32                        max_entries;          /*    36     4 */
              u32                        map_flags;            /*    40     4 */
              u32                        pages;                /*    44     4 */
              u32                        id;                   /*    48     4 */
              int                        numa_node;            /*    52     4 */
              bool                       unpriv_array;         /*    56     1 */
      
              /* XXX 7 bytes hole, try to pack */
      
              /* --- cacheline 1 boundary (64 bytes) --- */
              struct user_struct *       user;                 /*    64     8 */
              atomic_t                   refcnt;               /*    72     4 */
              atomic_t                   usercnt;              /*    76     4 */
              struct work_struct         work;                 /*    80    32 */
              char                       name[16];             /*   112    16 */
              /* --- cacheline 2 boundary (128 bytes) --- */
      
              /* size: 128, cachelines: 2, members: 17 */
              /* sum members: 121, holes: 1, sum holes: 7 */
        };
      
      Now all entries in the first cacheline are read only throughout
      the life time of the map, set up once during map creation. Overall
      struct size and number of cachelines doesn't change from the
      reordering. struct bpf_map is usually first member and embedded
      in map structs in specific map implementations, so also avoid those
      members to sit at the end where it could potentially share the
      cacheline with first map values e.g. in the array since remote
      CPUs could trigger map updates just as well for those (easily
      dirtying members like max_entries intentionally as well) while
      having subsequent values in cache.
      
      Quoting from Google's Project Zero blog [1]:
      
        Additionally, at least on the Intel machine on which this was
        tested, bouncing modified cache lines between cores is slow,
        apparently because the MESI protocol is used for cache coherence
        [8]. Changing the reference counter of an eBPF array on one
        physical CPU core causes the cache line containing the reference
        counter to be bounced over to that CPU core, making reads of the
        reference counter on all other CPU cores slow until the changed
        reference counter has been written back to memory. Because the
        length and the reference counter of an eBPF array are stored in
        the same cache line, this also means that changing the reference
        counter on one physical CPU core causes reads of the eBPF array's
        length to be slow on other physical CPU cores (intentional false
        sharing).
      
      While this doesn't 'control' the out-of-bounds speculation through
      masking the index as in commit b2157399, triggering a manipulation
      of the map's reference counter is really trivial, so lets not allow
      to easily affect max_entries from it.
      
      Splitting to separate cachelines also generally makes sense from
      a performance perspective anyway in that fast-path won't have a
      cache miss if the map gets pinned, reused in other progs, etc out
      of control path, thus also avoids unintentional false sharing.
      
        [1] https://googleprojectzero.blogspot.ch/2018/01/reading-privileged-memory-with-side.htmlSigned-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      be95a845
    • W
      ipv6: remove null_entry before adding default route · 4512c43e
      Wei Wang 提交于
      In the current code, when creating a new fib6 table, tb6_root.leaf gets
      initialized to net->ipv6.ip6_null_entry.
      If a default route is being added with rt->rt6i_metric = 0xffffffff,
      fib6_add() will add this route after net->ipv6.ip6_null_entry. As
      null_entry is shared, it could cause problem.
      
      In order to fix it, set fn->leaf to NULL before calling
      fib6_add_rt2node() when trying to add the first default route.
      And reset fn->leaf to null_entry when adding fails or when deleting the
      last default route.
      
      syzkaller reported the following issue which is fixed by this commit:
      
      WARNING: suspicious RCU usage
      4.15.0-rc5+ #171 Not tainted
      -----------------------------
      net/ipv6/ip6_fib.c:1702 suspicious rcu_dereference_protected() usage!
      
      other info that might help us debug this:
      
      rcu_scheduler_active = 2, debug_locks = 1
      4 locks held by swapper/0/0:
       #0:  ((&net->ipv6.ip6_fib_timer)){+.-.}, at: [<00000000d43f631b>] lockdep_copy_map include/linux/lockdep.h:178 [inline]
       #0:  ((&net->ipv6.ip6_fib_timer)){+.-.}, at: [<00000000d43f631b>] call_timer_fn+0x1c6/0x820 kernel/time/timer.c:1310
       #1:  (&(&net->ipv6.fib6_gc_lock)->rlock){+.-.}, at: [<000000002ff9d65c>] spin_lock_bh include/linux/spinlock.h:315 [inline]
       #1:  (&(&net->ipv6.fib6_gc_lock)->rlock){+.-.}, at: [<000000002ff9d65c>] fib6_run_gc+0x9d/0x3c0 net/ipv6/ip6_fib.c:2007
       #2:  (rcu_read_lock){....}, at: [<0000000091db762d>] __fib6_clean_all+0x0/0x3a0 net/ipv6/ip6_fib.c:1560
       #3:  (&(&tb->tb6_lock)->rlock){+.-.}, at: [<000000009e503581>] spin_lock_bh include/linux/spinlock.h:315 [inline]
       #3:  (&(&tb->tb6_lock)->rlock){+.-.}, at: [<000000009e503581>] __fib6_clean_all+0x1d0/0x3a0 net/ipv6/ip6_fib.c:1948
      
      stack backtrace:
      CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.15.0-rc5+ #171
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
      Call Trace:
       <IRQ>
       __dump_stack lib/dump_stack.c:17 [inline]
       dump_stack+0x194/0x257 lib/dump_stack.c:53
       lockdep_rcu_suspicious+0x123/0x170 kernel/locking/lockdep.c:4585
       fib6_del+0xcaa/0x11b0 net/ipv6/ip6_fib.c:1701
       fib6_clean_node+0x3aa/0x4f0 net/ipv6/ip6_fib.c:1892
       fib6_walk_continue+0x46c/0x8a0 net/ipv6/ip6_fib.c:1815
       fib6_walk+0x91/0xf0 net/ipv6/ip6_fib.c:1863
       fib6_clean_tree+0x1e6/0x340 net/ipv6/ip6_fib.c:1933
       __fib6_clean_all+0x1f4/0x3a0 net/ipv6/ip6_fib.c:1949
       fib6_clean_all net/ipv6/ip6_fib.c:1960 [inline]
       fib6_run_gc+0x16b/0x3c0 net/ipv6/ip6_fib.c:2016
       fib6_gc_timer_cb+0x20/0x30 net/ipv6/ip6_fib.c:2033
       call_timer_fn+0x228/0x820 kernel/time/timer.c:1320
       expire_timers kernel/time/timer.c:1357 [inline]
       __run_timers+0x7ee/0xb70 kernel/time/timer.c:1660
       run_timer_softirq+0x4c/0xb0 kernel/time/timer.c:1686
       __do_softirq+0x2d7/0xb85 kernel/softirq.c:285
       invoke_softirq kernel/softirq.c:365 [inline]
       irq_exit+0x1cc/0x200 kernel/softirq.c:405
       exiting_irq arch/x86/include/asm/apic.h:540 [inline]
       smp_apic_timer_interrupt+0x16b/0x700 arch/x86/kernel/apic/apic.c:1052
       apic_timer_interrupt+0xa9/0xb0 arch/x86/entry/entry_64.S:904
       </IRQ>
      Reported-by: Nsyzbot <syzkaller@googlegroups.com>
      Fixes: 66f5d6ce ("ipv6: replace rwlock with rcu and spinlock in fib6_table")
      Signed-off-by: NWei Wang <weiwan@google.com>
      Acked-by: NMartin KaFai Lau <kafai@fb.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      4512c43e
    • D
      Merge branch 'Ether-fixes-for-the-SolutionEngine771x-boards' · 22dd8e6b
      David S. Miller 提交于
      Sergei Shtylyov says:
      
      ====================
      Ether fixes for the SolutionEngine771x boards
      
      Here's the series of 2 patches against Linus' repo. This series should
      (hoplefully) fix the Ether support on the SolutionEngine771x boards...
      
      [1/2] SolutionEngine771x: fix Ether platform data
      [2/2] SolutionEngine771x: add Ether TSU resource
      ====================
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      22dd8e6b
    • S
      SolutionEngine771x: add Ether TSU resource · f9a531d6
      Sergei Shtylyov 提交于
      After the  Ether platform data is fixed, the driver probe() method would
      still fail since the 'struct sh_eth_cpu_data' corresponding  to SH771x
      indicates the presence of TSU but the memory resource for it is absent.
      Add the missing TSU resource  to both Ether devices and fix the harmless
      off-by-one error in the main memory resources, while at it...
      
      Fixes: 4986b996 ("net: sh_eth: remove the SH_TSU_ADDR")
      Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f9a531d6
    • S
      SolutionEngine771x: fix Ether platform data · 195e2add
      Sergei Shtylyov 提交于
      The 'sh_eth' driver's probe() method would fail  on the SolutionEngine7710
      board and crash on SolutionEngine7712 board  as the platform code is
      hopelessly behind the driver's platform data --  it passes the PHY address
      instead of 'struct sh_eth_plat_data *'; pass the latter to the driver in
      order to fix the bug...
      
      Fixes: 71557a37 ("[netdrvr] sh_eth: Add SH7619 support")
      Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      195e2add
    • M
      docs-rst: networking: wire up msg_zerocopy · 2fdd1811
      Mike Rapoport 提交于
      Fix the following 'make htmldocs' complaint:
      
      Documentation/networking/msg_zerocopy.rst:: WARNING: document isn't included in any toctree.
      Signed-off-by: NMike Rapoport <rppt@linux.vnet.ibm.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2fdd1811
    • N
      net: ipv4: emulate READ_ONCE() on ->hdrincl bit-field in raw_sendmsg() · 20b50d79
      Nicolai Stange 提交于
      Commit 8f659a03 ("net: ipv4: fix for a race condition in
      raw_sendmsg") fixed the issue of possibly inconsistent ->hdrincl handling
      due to concurrent updates by reading this bit-field member into a local
      variable and using the thus stabilized value in subsequent tests.
      
      However, aforementioned commit also adds the (correct) comment that
      
        /* hdrincl should be READ_ONCE(inet->hdrincl)
         * but READ_ONCE() doesn't work with bit fields
         */
      
      because as it stands, the compiler is free to shortcut or even eliminate
      the local variable at its will.
      
      Note that I have not seen anything like this happening in reality and thus,
      the concern is a theoretical one.
      
      However, in order to be on the safe side, emulate a READ_ONCE() on the
      bit-field by doing it on the local 'hdrincl' variable itself:
      
      	int hdrincl = inet->hdrincl;
      	hdrincl = READ_ONCE(hdrincl);
      
      This breaks the chain in the sense that the compiler is not allowed
      to replace subsequent reads from hdrincl with reloads from inet->hdrincl.
      
      Fixes: 8f659a03 ("net: ipv4: fix for a race condition in raw_sendmsg")
      Signed-off-by: NNicolai Stange <nstange@suse.de>
      Reviewed-by: NStefano Brivio <sbrivio@redhat.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      20b50d79
    • X
      net: caif: use strlcpy() instead of strncpy() · 3dc2fa47
      Xiongfeng Wang 提交于
      gcc-8 reports
      
      net/caif/caif_dev.c: In function 'caif_enroll_dev':
      ./include/linux/string.h:245:9: warning: '__builtin_strncpy' output may
      be truncated copying 15 bytes from a string of length 15
      [-Wstringop-truncation]
      
      net/caif/cfctrl.c: In function 'cfctrl_linkup_request':
      ./include/linux/string.h:245:9: warning: '__builtin_strncpy' output may
      be truncated copying 15 bytes from a string of length 15
      [-Wstringop-truncation]
      
      net/caif/cfcnfg.c: In function 'caif_connect_client':
      ./include/linux/string.h:245:9: warning: '__builtin_strncpy' output may
      be truncated copying 15 bytes from a string of length 15
      [-Wstringop-truncation]
      
      The compiler require that the input param 'len' of strncpy() should be
      greater than the length of the src string, so that '\0' is copied as
      well. We can just use strlcpy() to avoid this warning.
      Signed-off-by: NXiongfeng Wang <xiongfeng.wang@linaro.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      3dc2fa47
    • A
      net: core: fix module type in sock_diag_bind · b8fd0823
      Andrii Vladyka 提交于
      Use AF_INET6 instead of AF_INET in IPv6-related code path
      Signed-off-by: NAndrii Vladyka <tulup@mail.ru>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      b8fd0823
  3. 09 1月, 2018 13 次提交
    • L
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net · ef7f8cec
      Linus Torvalds 提交于
      Pull networking fixes from David Miller:
      
       1) Frag and UDP handling fixes in i40e driver, from Amritha Nambiar and
          Alexander Duyck.
      
       2) Undo unintentional UAPI change in netfilter conntrack, from Florian
          Westphal.
      
       3) Revert a change to how error codes are returned from
          dev_get_valid_name(), it broke some apps.
      
       4) Cannot cache routes for ipv6 tunnels in the tunnel is ipv4/ipv6
          dual-stack. From Eli Cooper.
      
       5) Fix missed PMTU updates in geneve, from Xin Long.
      
       6) Cure double free in macvlan, from Gao Feng.
      
       7) Fix heap out-of-bounds write in rds_message_alloc_sgs(), from
          Mohamed Ghannam.
      
       8) FEC bug fixes from FUgang Duan (mis-accounting of dev_id, missed
          deferral of probe when the regulator is not ready yet).
      
       9) Missing DMA mapping error checks in 3c59x, from Neil Horman.
      
      10) Turn off Broadcom tags for some b53 switches, from Florian Fainelli.
      
      11) Fix OOPS when get_target_net() is passed an SKB whose NETLINK_CB()
          isn't initialized. From Andrei Vagin.
      
      12) Fix crashes in fib6_add(), from Wei Wang.
      
      13) PMTU bug fixes in SCTP from Marcelo Ricardo Leitner.
      
      * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (56 commits)
        sh_eth: fix TXALCR1 offsets
        mdio-sun4i: Fix a memory leak
        phylink: mark expected switch fall-throughs in phylink_mii_ioctl
        sctp: fix the handling of ICMP Frag Needed for too small MTUs
        sctp: do not retransmit upon FragNeeded if PMTU discovery is disabled
        xen-netfront: enable device after manual module load
        bnxt_en: Fix the 'Invalid VF' id check in bnxt_vf_ndo_prep routine.
        bnxt_en: Fix population of flow_type in bnxt_hwrm_cfa_flow_alloc()
        sh_eth: fix SH7757 GEther initialization
        net: fec: free/restore resource in related probe error pathes
        uapi/if_ether.h: prevent redefinition of struct ethhdr
        ipv6: fix general protection fault in fib6_add()
        RDS: null pointer dereference in rds_atomic_free_op
        sh_eth: fix TSU resource handling
        net: stmmac: enable EEE in MII, GMII or RGMII only
        rtnetlink: give a user socket to get_target_net()
        MAINTAINERS: Update my email address.
        can: ems_usb: improve error reporting for error warning and error passive
        can: flex_can: Correct the checking for frame length in flexcan_start_xmit()
        can: gs_usb: fix return value of the "set_bittiming" callback
        ...
      ef7f8cec
    • L
      Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma · 44596f86
      Linus Torvalds 提交于
      Pull rdma fixes from Doug Ledford:
      
       - One line fix to mlx4 error flow (same as mlx5 fix in last pull
         request, just in the mlx4 driver)
      
       - Fix a race condition in the IPoIB driver. This patch is larger than
         just a one line fix, but resolves a race condition in a fairly
         straight forward manner
      
       - Fix a locking issue in the RDMA netlink code. This patch is also
         larger than I would like for a late -rc. It has, however, had a week
         to bake in the rdma tree prior to this pull request
      
       - One line fix to fix granting remote machine access to memory that
         they don't need and shouldn't have
      
       - One line fix to correct the fact that our sgid/dgid pair is swapped
         from what you would expect when receiving an incoming connection
         request
      
      * tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
        IB/srpt: Fix ACL lookup during login
        IB/srpt: Disable RDMA access by the initiator
        RDMA/netlink: Fix locking around __ib_get_device_by_index
        IB/ipoib: Fix race condition in neigh creation
        IB/mlx4: Fix mlx4_ib_alloc_mr error flow
      44596f86
    • A
      bpf: prevent out-of-bounds speculation · b2157399
      Alexei Starovoitov 提交于
      Under speculation, CPUs may mis-predict branches in bounds checks. Thus,
      memory accesses under a bounds check may be speculated even if the
      bounds check fails, providing a primitive for building a side channel.
      
      To avoid leaking kernel data round up array-based maps and mask the index
      after bounds check, so speculated load with out of bounds index will load
      either valid value from the array or zero from the padded area.
      
      Unconditionally mask index for all array types even when max_entries
      are not rounded to power of 2 for root user.
      When map is created by unpriv user generate a sequence of bpf insns
      that includes AND operation to make sure that JITed code includes
      the same 'index & index_mask' operation.
      
      If prog_array map is created by unpriv user replace
        bpf_tail_call(ctx, map, index);
      with
        if (index >= max_entries) {
          index &= map->index_mask;
          bpf_tail_call(ctx, map, index);
        }
      (along with roundup to power 2) to prevent out-of-bounds speculation.
      There is secondary redundant 'if (index >= max_entries)' in the interpreter
      and in all JITs, but they can be optimized later if necessary.
      
      Other array-like maps (cpumap, devmap, sockmap, perf_event_array, cgroup_array)
      cannot be used by unpriv, so no changes there.
      
      That fixes bpf side of "Variant 1: bounds check bypass (CVE-2017-5753)" on
      all architectures with and without JIT.
      
      v2->v3:
      Daniel noticed that attack potentially can be crafted via syscall commands
      without loading the program, so add masking to those paths as well.
      Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      Acked-by: NJohn Fastabend <john.fastabend@gmail.com>
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      b2157399
    • L
      Merge tag 'platform-drivers-x86-v4.15-4' of git://git.infradead.org/linux-platform-drivers-x86 · d32da584
      Linus Torvalds 提交于
      Pull x86 platform driver fix from Darren Hart:
       "Address a wmi initcall ordering race resulting in a difficult to
        reproduce boot failure"
      
      * tag 'platform-drivers-x86-v4.15-4' of git://git.infradead.org/linux-platform-drivers-x86:
        platform/x86: wmi: Call acpi_wmi_init() later
      d32da584
    • S
      sh_eth: fix TXALCR1 offsets · 50f3d740
      Sergei Shtylyov 提交于
      The  TXALCR1 offsets are incorrect in the register offset tables, most
      probably due to copy&paste error.  Luckily, the driver never uses this
      register. :-)
      
      Fixes: 4a55530f ("net: sh_eth: modify the definitions of register")
      Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      50f3d740
    • C
      mdio-sun4i: Fix a memory leak · 56c02902
      Christophe JAILLET 提交于
      If the probing of the regulator is deferred, the memory allocated by
      'mdiobus_alloc_size()' will be leaking.
      It should be freed before the next call to 'sun4i_mdio_probe()' which will
      reallocate it.
      
      Fixes: 4bdcb1dd ("net: Add MDIO bus driver for the Allwinner EMAC")
      Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      56c02902
    • G
      phylink: mark expected switch fall-throughs in phylink_mii_ioctl · 46cd7503
      Gustavo A. R. Silva 提交于
      In preparation to enabling -Wimplicit-fallthrough, mark switch cases
      where we are expecting to fall through.
      
      Addresses-Coverity-ID: 1463447 ("Missing break in switch")
      Signed-off-by: NGustavo A. R. Silva <garsilva@embeddedor.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      46cd7503
    • D
      Merge branch 'SCTP-PMTU-discovery-fixes' · 313c86da
      David S. Miller 提交于
      Marcelo Ricardo Leitner says:
      
      ====================
      SCTP PMTU discovery fixes
      
      This patchset fixes 2 issues with PMTU discovery that can lead to flood
      of retransmissions.
      The first patch fixes the issue for when PMTUD is disabled by the
      application, while the second fixes it for when its enabled.
      
      Please consider these to stable.
      ====================
      Acked-by: NNeil Horman <nhorman@tuxdriver.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      313c86da
    • M
      sctp: fix the handling of ICMP Frag Needed for too small MTUs · b6c5734d
      Marcelo Ricardo Leitner 提交于
      syzbot reported a hang involving SCTP, on which it kept flooding dmesg
      with the message:
      [  246.742374] sctp: sctp_transport_update_pmtu: Reported pmtu 508 too
      low, using default minimum of 512
      
      That happened because whenever SCTP hits an ICMP Frag Needed, it tries
      to adjust to the new MTU and triggers an immediate retransmission. But
      it didn't consider the fact that MTUs smaller than the SCTP minimum MTU
      allowed (512) would not cause the PMTU to change, and issued the
      retransmission anyway (thus leading to another ICMP Frag Needed, and so
      on).
      
      As IPv4 (ip_rt_min_pmtu=556) and IPv6 (IPV6_MIN_MTU=1280) minimum MTU
      are higher than that, sctp_transport_update_pmtu() is changed to
      re-fetch the PMTU that got set after our request, and with that, detect
      if there was an actual change or not.
      
      The fix, thus, skips the immediate retransmission if the received ICMP
      resulted in no change, in the hope that SCTP will select another path.
      
      Note: The value being used for the minimum MTU (512,
      SCTP_DEFAULT_MINSEGMENT) is not right and instead it should be (576,
      SCTP_MIN_PMTU), but such change belongs to another patch.
      
      Changes from v1:
      - do not disable PMTU discovery, in the light of commit
      06ad3919 ("[SCTP] Don't disable PMTU discovery when mtu is small")
      and as suggested by Xin Long.
      - changed the way to break the rtx loop by detecting if the icmp
        resulted in a change or not
      Changes from v2:
      none
      
      See-also: https://lkml.org/lkml/2017/12/22/811Reported-by: Nsyzbot <syzkaller@googlegroups.com>
      Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      b6c5734d
    • M
      sctp: do not retransmit upon FragNeeded if PMTU discovery is disabled · cc35c3d1
      Marcelo Ricardo Leitner 提交于
      Currently, if PMTU discovery is disabled on a given transport, but the
      configured value is higher than the actual PMTU, it is likely that we
      will get some icmp Frag Needed. The issue is, if PMTU discovery is
      disabled, we won't update the information and will issue a
      retransmission immediately, which may very well trigger another ICMP,
      and another retransmission, leading to a loop.
      
      The fix is to simply not trigger immediate retransmissions if PMTU
      discovery is disabled on the given transport.
      
      Changes from v2:
      - updated stale comment, noticed by Xin Long
      Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      cc35c3d1
    • E
      xen-netfront: enable device after manual module load · b707fda2
      Eduardo Otubo 提交于
      When loading the module after unloading it, the network interface would
      not be enabled and thus wouldn't have a backend counterpart and unable
      to be used by the guest.
      
      The guest would face errors like:
      
        [root@guest ~]# ethtool -i eth0
        Cannot get driver information: No such device
      
        [root@guest ~]# ifconfig eth0
        eth0: error fetching interface information: Device not found
      
      This patch initializes the state of the netfront device whenever it is
      loaded manually, this state would communicate the netback to create its
      device and establish the connection between them.
      Signed-off-by: NEduardo Otubo <otubo@redhat.com>
      Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      b707fda2
    • D
      Merge branch 'bnxt_en_fixes' · bde21915
      David S. Miller 提交于
      Michael Chan says:
      
      ====================
      bnxt_en: 2 small bug fixes.
      
      The first one fixes the TC Flower flow parameter passed to firmware.  The
      2nd one fixes the VF index range checking for iproute2 SRIOV related commands.
      ====================
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      bde21915
    • V
      bnxt_en: Fix the 'Invalid VF' id check in bnxt_vf_ndo_prep routine. · 78f30004
      Venkat Duvvuru 提交于
      In bnxt_vf_ndo_prep (which is called by bnxt_get_vf_config ndo), there is a
      check for "Invalid VF id". Currently, the check is done against max_vfs.
      However, the user doesn't always create max_vfs. So, the check should be
      against the created number of VFs. The number of bnxt_vf_info structures
      that are allocated in bnxt_alloc_vf_resources routine is the "number of
      requested VFs". So, if an "invalid VF id" falls between the requested
      number of VFs and the max_vfs, the driver will be dereferencing an invalid
      pointer.
      
      Fixes: c0c050c5 ("bnxt_en: New Broadcom ethernet driver.")
      Signed-off-by: NVenkat Devvuru <venkatkumar.duvvuru@broadcom.com>
      Signed-off-by: NMichael Chan <michael.chan@broadcom.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      78f30004