1. 14 Dec, 2014 35 commits
  2. 05 Nov, 2014 5 commits
    • Ben Hutchings's avatar
      Linux 3.2.64 · 7d039b97
      Ben Hutchings authored
      7d039b97
    • Guillaume Nault's avatar
      l2tp: fix race while getting PMTU on PPP pseudo-wire · 544bd1bf
      Guillaume Nault authored
      commit eed4d839 upstream.
      
      Use dst_entry held by sk_dst_get() to retrieve tunnel's PMTU.
      
      The dst_mtu(__sk_dst_get(tunnel->sock)) call was racy. __sk_dst_get()
      could return NULL if tunnel->sock->sk_dst_cache was reset just before the
      call, thus making dst_mtu() dereference a NULL pointer:
      
      [ 1937.661598] BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
      [ 1937.664005] IP: [<ffffffffa049db88>] pppol2tp_connect+0x33d/0x41e [l2tp_ppp]
      [ 1937.664005] PGD daf0c067 PUD d9f93067 PMD 0
      [ 1937.664005] Oops: 0000 [#1] SMP
      [ 1937.664005] Modules linked in: l2tp_ppp l2tp_netlink l2tp_core ip6table_filter ip6_tables iptable_filter ip_tables ebtable_nat ebtables x_tables udp_tunnel pppoe pppox ppp_generic slhc deflate ctr twofish_generic twofish_x86_64_3way xts lrw gf128mul glue_helper twofish_x86_64 twofish_common blowfish_generic blowfish_x86_64 blowfish_common des_generic cbc xcbc rmd160 sha512_generic hmac crypto_null af_key xfrm_algo 8021q garp bridge stp llc tun atmtcp clip atm ext3 mbcache jbd iTCO_wdt coretemp kvm_intel iTCO_vendor_support kvm pcspkr evdev ehci_pci lpc_ich mfd_core i5400_edac edac_core i5k_amb shpchp button processor thermal_sys xfs crc32c_generic libcrc32c dm_mod usbhid sg hid sr_mod sd_mod cdrom crc_t10dif crct10dif_common ata_generic ahci ata_piix tg3 libahci libata uhci_hcd ptp ehci_hcd pps_core usbcore scsi_mod libphy usb_common [last unloaded: l2tp_core]
      [ 1937.664005] CPU: 0 PID: 10022 Comm: l2tpstress Tainted: G           O   3.17.0-rc1 #1
      [ 1937.664005] Hardware name: HP ProLiant DL160 G5, BIOS O12 08/22/2008
      [ 1937.664005] task: ffff8800d8fda790 ti: ffff8800c43c4000 task.ti: ffff8800c43c4000
      [ 1937.664005] RIP: 0010:[<ffffffffa049db88>]  [<ffffffffa049db88>] pppol2tp_connect+0x33d/0x41e [l2tp_ppp]
      [ 1937.664005] RSP: 0018:ffff8800c43c7de8  EFLAGS: 00010282
      [ 1937.664005] RAX: ffff8800da8a7240 RBX: ffff8800d8c64600 RCX: 000001c325a137b5
      [ 1937.664005] RDX: 8c6318c6318c6320 RSI: 000000000000010c RDI: 0000000000000000
      [ 1937.664005] RBP: ffff8800c43c7ea8 R08: 0000000000000000 R09: 0000000000000000
      [ 1937.664005] R10: ffffffffa048e2c0 R11: ffff8800d8c64600 R12: ffff8800ca7a5000
      [ 1937.664005] R13: ffff8800c439bf40 R14: 000000000000000c R15: 0000000000000009
      [ 1937.664005] FS:  00007fd7f610f700(0000) GS:ffff88011a600000(0000) knlGS:0000000000000000
      [ 1937.664005] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
      [ 1937.664005] CR2: 0000000000000020 CR3: 00000000d9d75000 CR4: 00000000000027e0
      [ 1937.664005] Stack:
      [ 1937.664005]  ffffffffa049da80 ffff8800d8fda790 000000000000005b ffff880000000009
      [ 1937.664005]  ffff8800daf3f200 0000000000000003 ffff8800c43c7e48 ffffffff81109b57
      [ 1937.664005]  ffffffff81109b0e ffffffff8114c566 0000000000000000 0000000000000000
      [ 1937.664005] Call Trace:
      [ 1937.664005]  [<ffffffffa049da80>] ? pppol2tp_connect+0x235/0x41e [l2tp_ppp]
      [ 1937.664005]  [<ffffffff81109b57>] ? might_fault+0x9e/0xa5
      [ 1937.664005]  [<ffffffff81109b0e>] ? might_fault+0x55/0xa5
      [ 1937.664005]  [<ffffffff8114c566>] ? rcu_read_unlock+0x1c/0x26
      [ 1937.664005]  [<ffffffff81309196>] SYSC_connect+0x87/0xb1
      [ 1937.664005]  [<ffffffff813e56f7>] ? sysret_check+0x1b/0x56
      [ 1937.664005]  [<ffffffff8107590d>] ? trace_hardirqs_on_caller+0x145/0x1a1
      [ 1937.664005]  [<ffffffff81213dee>] ? trace_hardirqs_on_thunk+0x3a/0x3f
      [ 1937.664005]  [<ffffffff8114c262>] ? spin_lock+0x9/0xb
      [ 1937.664005]  [<ffffffff813092b4>] SyS_connect+0x9/0xb
      [ 1937.664005]  [<ffffffff813e56d2>] system_call_fastpath+0x16/0x1b
      [ 1937.664005] Code: 10 2a 84 81 e8 65 76 bd e0 65 ff 0c 25 10 bb 00 00 4d 85 ed 74 37 48 8b 85 60 ff ff ff 48 8b 80 88 01 00 00 48 8b b8 10 02 00 00 <48> 8b 47 20 ff 50 20 85 c0 74 0f 83 e8 28 89 83 10 01 00 00 89
      [ 1937.664005] RIP  [<ffffffffa049db88>] pppol2tp_connect+0x33d/0x41e [l2tp_ppp]
      [ 1937.664005]  RSP <ffff8800c43c7de8>
      [ 1937.664005] CR2: 0000000000000020
      [ 1939.559375] ---[ end trace 82d44500f28f8708 ]---
      
      Fixes: f34c4a35 ("l2tp: take PMTU from tunnel UDP socket")
      Signed-off-by: default avatarGuillaume Nault <g.nault@alphalink.fr>
      Acked-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      544bd1bf
    • Nadav Amit's avatar
      KVM: x86: Fix far-jump to non-canonical check · 77e4d28c
      Nadav Amit authored
      commit 7e46dddd upstream.
      
      Commit d1442d85 ("KVM: x86: Handle errors when RIP is set during far
      jumps") introduced a bug that caused the fix to be incomplete.  Due to
      incorrect evaluation, far jump to segment with L bit cleared (i.e., 32-bit
      segment) and RIP with any of the high bits set (i.e, RIP[63:32] != 0) set may
      not trigger #GP.  As we know, this imposes a security problem.
      
      In addition, the condition for two warnings was incorrect.
      
      Fixes: d1442d85Reported-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
      Signed-off-by: default avatarNadav Amit <namit@cs.technion.ac.il>
      [Add #ifdef CONFIG_X86_64 to avoid complaints of undefined behavior. - Paolo]
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      77e4d28c
    • Jens Axboe's avatar
      genhd: fix leftover might_sleep() in blk_free_devt() · 607530bf
      Jens Axboe authored
      commit 46f341ff upstream.
      
      Commit 2da78092 changed the locking from a mutex to a spinlock,
      so we now longer sleep in this context. But there was a leftover
      might_sleep() in there, which now triggers since we do the final
      free from an RCU callback. Get rid of it.
      Reported-by: default avatarPontus Fuchs <pontus.fuchs@gmail.com>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      607530bf
    • Steven Rostedt (Red Hat)'s avatar
      ring-buffer: Fix infinite spin in reading buffer · 77179bb8
      Steven Rostedt (Red Hat) authored
      commit 24607f11 upstream.
      
      Commit 651e22f2 "ring-buffer: Always reset iterator to reader page"
      fixed one bug but in the process caused another one. The reset is to
      update the header page, but that fix also changed the way the cached
      reads were updated. The cache reads are used to test if an iterator
      needs to be updated or not.
      
      A ring buffer iterator, when created, disables writes to the ring buffer
      but does not stop other readers or consuming reads from happening.
      Although all readers are synchronized via a lock, they are only
      synchronized when in the ring buffer functions. Those functions may
      be called by any number of readers. The iterator continues down when
      its not interrupted by a consuming reader. If a consuming read
      occurs, the iterator starts from the beginning of the buffer.
      
      The way the iterator sees that a consuming read has happened since
      its last read is by checking the reader "cache". The cache holds the
      last counts of the read and the reader page itself.
      
      Commit 651e22f2 changed what was saved by the cache_read when
      the rb_iter_reset() occurred, making the iterator never match the cache.
      Then if the iterator calls rb_iter_reset(), it will go into an
      infinite loop by checking if the cache doesn't match, doing the reset
      and retrying, just to see that the cache still doesn't match! Which
      should never happen as the reset is suppose to set the cache to the
      current value and there's locks that keep a consuming reader from
      having access to the data.
      
      Fixes: 651e22f2 "ring-buffer: Always reset iterator to reader page"
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      77179bb8