1. 25 Feb, 2018 9 commits
    • Xin Long's avatar
      sctp: set frag_point in sctp_setsockopt_maxseg correctly · 2e671223
      Xin Long authored
      commit ecca8f88 upstream.
      
      Now in sctp_setsockopt_maxseg user_frag or frag_point can be set with
      val >= 8 and val <= SCTP_MAX_CHUNK_LEN. But both checks are incorrect.
      
      val >= 8 means frag_point can even be less than SCTP_DEFAULT_MINSEGMENT.
      Then in sctp_datamsg_from_user(), when it's value is greater than cookie
      echo len and trying to bundle with cookie echo chunk, the first_len will
      overflow.
      
      The worse case is when it's value is equal as cookie echo len, first_len
      becomes 0, it will go into a dead loop for fragment later on. In Hangbin
      syzkaller testing env, oom was even triggered due to consecutive memory
      allocation in that loop.
      
      Besides, SCTP_MAX_CHUNK_LEN is the max size of the whole chunk, it should
      deduct the data header for frag_point or user_frag check.
      
      This patch does a proper check with SCTP_DEFAULT_MINSEGMENT subtracting
      the sctphdr and datahdr, SCTP_MAX_CHUNK_LEN subtracting datahdr when
      setting frag_point via sockopt. It also improves sctp_setsockopt_maxseg
      codes.
      Suggested-by: default avatarMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
      Reported-by: default avatarHangbin Liu <liuhangbin@gmail.com>
      Signed-off-by: default avatarXin Long <lucien.xin@gmail.com>
      Acked-by: default avatarMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      2e671223
    • Cong Wang's avatar
      xfrm: check id proto in validate_tmpl() · 85552886
      Cong Wang authored
      commit 6a53b759 upstream.
      
      syzbot reported a kernel warning in xfrm_state_fini(), which
      indicates that we have entries left in the list
      net->xfrm.state_all whose proto is zero. And
      xfrm_id_proto_match() doesn't consider them as a match with
      IPSEC_PROTO_ANY in this case.
      
      Proto with value 0 is probably not a valid value, at least
      verify_newsa_info() doesn't consider it valid either.
      
      This patch fixes it by checking the proto value in
      validate_tmpl() and rejecting invalid ones, like what iproute2
      does in xfrm_xfrmproto_getbyname().
      Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
      Cc: Steffen Klassert <steffen.klassert@secunet.com>
      Cc: Herbert Xu <herbert@gondor.apana.org.au>
      Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
      Signed-off-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      85552886
    • Steffen Klassert's avatar
      xfrm: Fix stack-out-of-bounds read on socket policy lookup. · 46b31716
      Steffen Klassert authored
      commit ddc47e44 upstream.
      
      When we do tunnel or beet mode, we pass saddr and daddr from the
      template to xfrm_state_find(), this is ok. On transport mode,
      we pass the addresses from the flowi, assuming that the IP
      addresses (and address family) don't change during transformation.
      This assumption is wrong in the IPv4 mapped IPv6 case, packet
      is IPv4 and template is IPv6.
      
      Fix this by catching address family missmatches of the policy
      and the flow already before we do the lookup.
      Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
      Signed-off-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      46b31716
    • Tetsuo Handa's avatar
      mm,vmscan: Make unregister_shrinker() no-op if register_shrinker() failed. · 274ee93f
      Tetsuo Handa authored
      commit bb422a73 upstream.
      
      Syzbot caught an oops at unregister_shrinker() because combination of
      commit 1d3d4437 ("vmscan: per-node deferred work") and fault
      injection made register_shrinker() fail and the caller of
      register_shrinker() did not check for failure.
      
      ----------
      [  554.881422] FAULT_INJECTION: forcing a failure.
      [  554.881422] name failslab, interval 1, probability 0, space 0, times 0
      [  554.881438] CPU: 1 PID: 13231 Comm: syz-executor1 Not tainted 4.14.0-rc8+ #82
      [  554.881443] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
      [  554.881445] Call Trace:
      [  554.881459]  dump_stack+0x194/0x257
      [  554.881474]  ? arch_local_irq_restore+0x53/0x53
      [  554.881486]  ? find_held_lock+0x35/0x1d0
      [  554.881507]  should_fail+0x8c0/0xa40
      [  554.881522]  ? fault_create_debugfs_attr+0x1f0/0x1f0
      [  554.881537]  ? check_noncircular+0x20/0x20
      [  554.881546]  ? find_next_zero_bit+0x2c/0x40
      [  554.881560]  ? ida_get_new_above+0x421/0x9d0
      [  554.881577]  ? find_held_lock+0x35/0x1d0
      [  554.881594]  ? __lock_is_held+0xb6/0x140
      [  554.881628]  ? check_same_owner+0x320/0x320
      [  554.881634]  ? lock_downgrade+0x990/0x990
      [  554.881649]  ? find_held_lock+0x35/0x1d0
      [  554.881672]  should_failslab+0xec/0x120
      [  554.881684]  __kmalloc+0x63/0x760
      [  554.881692]  ? lock_downgrade+0x990/0x990
      [  554.881712]  ? register_shrinker+0x10e/0x2d0
      [  554.881721]  ? trace_event_raw_event_module_request+0x320/0x320
      [  554.881737]  register_shrinker+0x10e/0x2d0
      [  554.881747]  ? prepare_kswapd_sleep+0x1f0/0x1f0
      [  554.881755]  ? _down_write_nest_lock+0x120/0x120
      [  554.881765]  ? memcpy+0x45/0x50
      [  554.881785]  sget_userns+0xbcd/0xe20
      (...snipped...)
      [  554.898693] kasan: CONFIG_KASAN_INLINE enabled
      [  554.898724] kasan: GPF could be caused by NULL-ptr deref or user memory access
      [  554.898732] general protection fault: 0000 [#1] SMP KASAN
      [  554.898737] Dumping ftrace buffer:
      [  554.898741]    (ftrace buffer empty)
      [  554.898743] Modules linked in:
      [  554.898752] CPU: 1 PID: 13231 Comm: syz-executor1 Not tainted 4.14.0-rc8+ #82
      [  554.898755] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
      [  554.898760] task: ffff8801d1dbe5c0 task.stack: ffff8801c9e38000
      [  554.898772] RIP: 0010:__list_del_entry_valid+0x7e/0x150
      [  554.898775] RSP: 0018:ffff8801c9e3f108 EFLAGS: 00010246
      [  554.898780] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
      [  554.898784] RDX: 0000000000000000 RSI: ffff8801c53c6f98 RDI: ffff8801c53c6fa0
      [  554.898788] RBP: ffff8801c9e3f120 R08: 1ffff100393c7d55 R09: 0000000000000004
      [  554.898791] R10: ffff8801c9e3ef70 R11: 0000000000000000 R12: 0000000000000000
      [  554.898795] R13: dffffc0000000000 R14: 1ffff100393c7e45 R15: ffff8801c53c6f98
      [  554.898800] FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
      [  554.898804] CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
      [  554.898807] CR2: 00000000dbc23000 CR3: 00000001c7269000 CR4: 00000000001406e0
      [  554.898813] DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
      [  554.898816] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
      [  554.898818] Call Trace:
      [  554.898828]  unregister_shrinker+0x79/0x300
      [  554.898837]  ? perf_trace_mm_vmscan_writepage+0x750/0x750
      [  554.898844]  ? down_write+0x87/0x120
      [  554.898851]  ? deactivate_super+0x139/0x1b0
      [  554.898857]  ? down_read+0x150/0x150
      [  554.898864]  ? check_same_owner+0x320/0x320
      [  554.898875]  deactivate_locked_super+0x64/0xd0
      [  554.898883]  deactivate_super+0x141/0x1b0
      ----------
      
      Since allowing register_shrinker() callers to call unregister_shrinker()
      when register_shrinker() failed can simplify error recovery path, this
      patch makes unregister_shrinker() no-op when register_shrinker() failed.
      Also, reset shrinker->nr_deferred in case unregister_shrinker() was
      by error called twice.
      Signed-off-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
      Signed-off-by: default avatarAliaksei Karaliou <akaraliou.dev@gmail.com>
      Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
      Cc: Glauber Costa <glauber@scylladb.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      274ee93f
    • Florian Westphal's avatar
      xfrm: skip policies marked as dead while rehashing · 5d89917c
      Florian Westphal authored
      commit 862591bf upstream.
      
      syzkaller triggered following KASAN splat:
      
      BUG: KASAN: slab-out-of-bounds in xfrm_hash_rebuild+0xdbe/0xf00 net/xfrm/xfrm_policy.c:618
      read of size 2 at addr ffff8801c8e92fe4 by task kworker/1:1/23 [..]
      Workqueue: events xfrm_hash_rebuild [..]
       __asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:428
       xfrm_hash_rebuild+0xdbe/0xf00 net/xfrm/xfrm_policy.c:618
       process_one_work+0xbbf/0x1b10 kernel/workqueue.c:2112
       worker_thread+0x223/0x1990 kernel/workqueue.c:2246 [..]
      
      The reproducer triggers:
      1016                 if (error) {
      1017                         list_move_tail(&walk->walk.all, &x->all);
      1018                         goto out;
      1019                 }
      
      in xfrm_policy_walk() via pfkey (it sets tiny rcv space, dump
      callback returns -ENOBUFS).
      
      In this case, *walk is located the pfkey socket struct, so this socket
      becomes visible in the global policy list.
      
      It looks like this is intentional -- phony walker has walk.dead set to 1
      and all other places skip such "policies".
      
      Ccing original authors of the two commits that seem to expose this
      issue (first patch missed ->dead check, second patch adds pfkey
      sockets to policies dumper list).
      
      Fixes: 880a6fab ("xfrm: configure policy hash table thresholds by netlink")
      Fixes: 12a169e7 ("ipsec: Put dumpers on the dump list")
      Cc: Herbert Xu <herbert@gondor.apana.org.au>
      Cc: Timo Teras <timo.teras@iki.fi>
      Cc: Christophe Gouault <christophe.gouault@6wind.com>
      Reported-by: default avatarsyzbot <bot+c028095236fcb6f4348811565b75084c754dc729@syzkaller.appspotmail.com>
      Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
      Signed-off-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      5d89917c
    • Johannes Berg's avatar
      cfg80211: check dev_set_name() return value · 75898034
      Johannes Berg authored
      commit 59b179b4 upstream.
      
      syzbot reported a warning from rfkill_alloc(), and after a while
      I think that the reason is that it was doing fault injection and
      the dev_set_name() failed, leaving the name NULL, and we didn't
      check the return value and got to rfkill_alloc() with a NULL name.
      Since we really don't want a NULL name, we ought to check the
      return value.
      
      Fixes: fb28ad35 ("net: struct device - replace bus_id with dev_name(), dev_set_name()")
      Reported-by: syzbot+1ddfb3357e1d7bb5b5d3@syzkaller.appspotmail.com
      Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      75898034
    • Tom Herbert's avatar
      kcm: Only allow TCP sockets to be attached to a KCM mux · 2bb174af
      Tom Herbert authored
      commit 581e7226 upstream.
      
      TCP sockets for IPv4 and IPv6 that are not listeners or in closed
      stated are allowed to be attached to a KCM mux.
      
      Fixes: ab7ac4eb ("kcm: Kernel Connection Multiplexor module")
      Reported-by: syzbot+8865eaff7f9acd593945@syzkaller.appspotmail.com
      Signed-off-by: default avatarTom Herbert <tom@quantonium.net>
      Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      2bb174af
    • Tom Herbert's avatar
      kcm: Check if sk_user_data already set in kcm_attach · 085cbbda
      Tom Herbert authored
      commit e5571240 upstream.
      
      This is needed to prevent sk_user_data being overwritten.
      The check is done under the callback lock. This should prevent
      a socket from being attached twice to a KCM mux. It also prevents
      a socket from being attached for other use cases of sk_user_data
      as long as the other cases set sk_user_data under the lock.
      Followup work is needed to unify all the use cases of sk_user_data
      to use the same locking.
      
      Reported-by: syzbot+114b15f2be420a8886c3@syzkaller.appspotmail.com
      Fixes: ab7ac4eb ("kcm: Kernel Connection Multiplexor module")
      Signed-off-by: default avatarTom Herbert <tom@quantonium.net>
      Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      085cbbda
    • Jason Wang's avatar
      vhost: use mutex_lock_nested() in vhost_dev_lock_vqs() · bd3ccdc6
      Jason Wang authored
      commit e9cb4239 upstream.
      
      We used to call mutex_lock() in vhost_dev_lock_vqs() which tries to
      hold mutexes of all virtqueues. This may confuse lockdep to report a
      possible deadlock because of trying to hold locks belong to same
      class. Switch to use mutex_lock_nested() to avoid false positive.
      
      Fixes: 6b1e6cc7 ("vhost: new device IOTLB API")
      Reported-by: syzbot+dbb7c1161485e61b0241@syzkaller.appspotmail.com
      Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
      Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      bd3ccdc6
  2. 22 Feb, 2018 31 commits