1. 05 Dec, 2015 15 commits
    • Masahiro Yamada's avatar
      devres: fix devres_get() · 9bc0d009
      Masahiro Yamada authored
      commit 64526370 upstream.
      
      Currently, devres_get() passes devres_free() the pointer to devres,
      but devres_free() should be given with the pointer to resource data.
      
      Fixes: 9ac7849e ("devres: device resource management")
      Signed-off-by: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
      Acked-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      (cherry picked from commit ebc0ae5a)
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      9bc0d009
    • Herton R. Krzesinski's avatar
      ipc,sem: fix use after free on IPC_RMID after a task using same semaphore set exits · 8c367f5c
      Herton R. Krzesinski authored
      commit 602b8593 upstream.
      
      The current semaphore code allows a potential use after free: in
      exit_sem we may free the task's sem_undo_list while there is still
      another task looping through the same semaphore set and cleaning the
      sem_undo list at freeary function (the task called IPC_RMID for the same
      semaphore set).
      
      For example, with a test program [1] running which keeps forking a lot
      of processes (which then do a semop call with SEM_UNDO flag), and with
      the parent right after removing the semaphore set with IPC_RMID, and a
      kernel built with CONFIG_SLAB, CONFIG_SLAB_DEBUG and
      CONFIG_DEBUG_SPINLOCK, you can easily see something like the following
      in the kernel log:
      
         Slab corruption (Not tainted): kmalloc-64 start=ffff88003b45c1c0, len=64
         000: 6b 6b 6b 6b 6b 6b 6b 6b 00 6b 6b 6b 6b 6b 6b 6b  kkkkkkkk.kkkkkkk
         010: ff ff ff ff 6b 6b 6b 6b ff ff ff ff ff ff ff ff  ....kkkk........
         Prev obj: start=ffff88003b45c180, len=64
         000: 00 00 00 00 ad 4e ad de ff ff ff ff 5a 5a 5a 5a  .....N......ZZZZ
         010: ff ff ff ff ff ff ff ff c0 fb 01 37 00 88 ff ff  ...........7....
         Next obj: start=ffff88003b45c200, len=64
         000: 00 00 00 00 ad 4e ad de ff ff ff ff 5a 5a 5a 5a  .....N......ZZZZ
         010: ff ff ff ff ff ff ff ff 68 29 a7 3c 00 88 ff ff  ........h).<....
         BUG: spinlock wrong CPU on CPU#2, test/18028
         general protection fault: 0000 [#1] SMP
         Modules linked in: 8021q mrp garp stp llc nf_conntrack_ipv4 nf_defrag_ipv4 ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables binfmt_misc ppdev input_leds joydev parport_pc parport floppy serio_raw virtio_balloon virtio_rng virtio_console virtio_net iosf_mbi crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcspkr qxl ttm drm_kms_helper drm snd_hda_codec_generic i2c_piix4 snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer snd soundcore crc32c_intel virtio_pci virtio_ring virtio pata_acpi ata_generic [last unloaded: speedstep_lib]
         CPU: 2 PID: 18028 Comm: test Not tainted 4.2.0-rc5+ #1
         Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014
         RIP: spin_dump+0x53/0xc0
         Call Trace:
           spin_bug+0x30/0x40
           do_raw_spin_unlock+0x71/0xa0
           _raw_spin_unlock+0xe/0x10
           freeary+0x82/0x2a0
           ? _raw_spin_lock+0xe/0x10
           semctl_down.clone.0+0xce/0x160
           ? __do_page_fault+0x19a/0x430
           ? __audit_syscall_entry+0xa8/0x100
           SyS_semctl+0x236/0x2c0
           ? syscall_trace_leave+0xde/0x130
           entry_SYSCALL_64_fastpath+0x12/0x71
         Code: 8b 80 88 03 00 00 48 8d 88 60 05 00 00 48 c7 c7 a0 2c a4 81 31 c0 65 8b 15 eb 40 f3 7e e8 08 31 68 00 4d 85 e4 44 8b 4b 08 74 5e <45> 8b 84 24 88 03 00 00 49 8d 8c 24 60 05 00 00 8b 53 04 48 89
         RIP  [<ffffffff810d6053>] spin_dump+0x53/0xc0
          RSP <ffff88003750fd68>
         ---[ end trace 783ebb76612867a0 ]---
         NMI watchdog: BUG: soft lockup - CPU#3 stuck for 22s! [test:18053]
         Modules linked in: 8021q mrp garp stp llc nf_conntrack_ipv4 nf_defrag_ipv4 ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables binfmt_misc ppdev input_leds joydev parport_pc parport floppy serio_raw virtio_balloon virtio_rng virtio_console virtio_net iosf_mbi crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcspkr qxl ttm drm_kms_helper drm snd_hda_codec_generic i2c_piix4 snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer snd soundcore crc32c_intel virtio_pci virtio_ring virtio pata_acpi ata_generic [last unloaded: speedstep_lib]
         CPU: 3 PID: 18053 Comm: test Tainted: G      D         4.2.0-rc5+ #1
         Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014
         RIP: native_read_tsc+0x0/0x20
         Call Trace:
           ? delay_tsc+0x40/0x70
           __delay+0xf/0x20
           do_raw_spin_lock+0x96/0x140
           _raw_spin_lock+0xe/0x10
           sem_lock_and_putref+0x11/0x70
           SYSC_semtimedop+0x7bf/0x960
           ? handle_mm_fault+0xbf6/0x1880
           ? dequeue_task_fair+0x79/0x4a0
           ? __do_page_fault+0x19a/0x430
           ? kfree_debugcheck+0x16/0x40
           ? __do_page_fault+0x19a/0x430
           ? __audit_syscall_entry+0xa8/0x100
           ? do_audit_syscall_entry+0x66/0x70
           ? syscall_trace_enter_phase1+0x139/0x160
           SyS_semtimedop+0xe/0x10
           SyS_semop+0x10/0x20
           entry_SYSCALL_64_fastpath+0x12/0x71
         Code: 47 10 83 e8 01 85 c0 89 47 10 75 08 65 48 89 3d 1f 74 ff 7e c9 c3 0f 1f 44 00 00 55 48 89 e5 e8 87 17 04 00 66 90 c9 c3 0f 1f 00 <55> 48 89 e5 0f 31 89 c1 48 89 d0 48 c1 e0 20 89 c9 48 09 c8 c9
         Kernel panic - not syncing: softlockup: hung tasks
      
      I wasn't able to trigger any badness on a recent kernel without the
      proper config debugs enabled, however I have softlockup reports on some
      kernel versions, in the semaphore code, which are similar as above (the
      scenario is seen on some servers running IBM DB2 which uses semaphore
      syscalls).
      
      The patch here fixes the race against freeary, by acquiring or waiting
      on the sem_undo_list lock as necessary (exit_sem can race with freeary,
      while freeary sets un->semid to -1 and removes the same sem_undo from
      list_proc or when it removes the last sem_undo).
      
      After the patch I'm unable to reproduce the problem using the test case
      [1].
      
      [1] Test case used below:
      
          #include <stdio.h>
          #include <sys/types.h>
          #include <sys/ipc.h>
          #include <sys/sem.h>
          #include <sys/wait.h>
          #include <stdlib.h>
          #include <time.h>
          #include <unistd.h>
          #include <errno.h>
      
          #define NSEM 1
          #define NSET 5
      
          int sid[NSET];
      
          void thread()
          {
                  struct sembuf op;
                  int s;
                  uid_t pid = getuid();
      
                  s = rand() % NSET;
                  op.sem_num = pid % NSEM;
                  op.sem_op = 1;
                  op.sem_flg = SEM_UNDO;
      
                  semop(sid[s], &op, 1);
                  exit(EXIT_SUCCESS);
          }
      
          void create_set()
          {
                  int i, j;
                  pid_t p;
                  union {
                          int val;
                          struct semid_ds *buf;
                          unsigned short int *array;
                          struct seminfo *__buf;
                  } un;
      
                  /* Create and initialize semaphore set */
                  for (i = 0; i < NSET; i++) {
                          sid[i] = semget(IPC_PRIVATE , NSEM, 0644 | IPC_CREAT);
                          if (sid[i] < 0) {
                                  perror("semget");
                                  exit(EXIT_FAILURE);
                          }
                  }
                  un.val = 0;
                  for (i = 0; i < NSET; i++) {
                          for (j = 0; j < NSEM; j++) {
                                  if (semctl(sid[i], j, SETVAL, un) < 0)
                                          perror("semctl");
                          }
                  }
      
                  /* Launch threads that operate on semaphore set */
                  for (i = 0; i < NSEM * NSET * NSET; i++) {
                          p = fork();
                          if (p < 0)
                                  perror("fork");
                          if (p == 0)
                                  thread();
                  }
      
                  /* Free semaphore set */
                  for (i = 0; i < NSET; i++) {
                          if (semctl(sid[i], NSEM, IPC_RMID))
                                  perror("IPC_RMID");
                  }
      
                  /* Wait for forked processes to exit */
                  while (wait(NULL)) {
                          if (errno == ECHILD)
                                  break;
                  };
          }
      
          int main(int argc, char **argv)
          {
                  pid_t p;
      
                  srand(time(NULL));
      
                  while (1) {
                          p = fork();
                          if (p < 0) {
                                  perror("fork");
                                  exit(EXIT_FAILURE);
                          }
                          if (p == 0) {
                                  create_set();
                                  goto end;
                          }
      
                          /* Wait for forked processes to exit */
                          while (wait(NULL)) {
                                  if (errno == ECHILD)
                                          break;
                          };
                  }
          end:
                  return 0;
          }
      
      [akpm@linux-foundation.org: use normal comment layout]
      Signed-off-by: default avatarHerton R. Krzesinski <herton@redhat.com>
      Acked-by: default avatarManfred Spraul <manfred@colorfullife.com>
      Cc: Davidlohr Bueso <dave@stgolabs.net>
      Cc: Rafael Aquini <aquini@redhat.com>
      CC: Aristeu Rozanski <aris@redhat.com>
      Cc: David Jeffery <djeffery@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      [bwh: Backported to 3.2: adjust context]
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      (cherry picked from commit a1c4fb80)
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      8c367f5c
    • Herbert Xu's avatar
      net: Fix skb_set_peeked use-after-free bug · f7152084
      Herbert Xu authored
      commit a0a2a660 upstream.
      
      The commit 738ac1eb ("net: Clone
      skb before setting peeked flag") introduced a use-after-free bug
      in skb_recv_datagram.  This is because skb_set_peeked may create
      a new skb and free the existing one.  As it stands the caller will
      continue to use the old freed skb.
      
      This patch fixes it by making skb_set_peeked return the new skb
      (or the old one if unchanged).
      
      Fixes: 738ac1eb ("net: Clone skb before setting peeked flag")
      Reported-by: default avatarBrenden Blanco <bblanco@plumgrid.com>
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      Tested-by: default avatarBrenden Blanco <bblanco@plumgrid.com>
      Reviewed-by: default avatarKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      (cherry picked from commit e553622c)
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      f7152084
    • Herbert Xu's avatar
      net: Clone skb before setting peeked flag · 52501955
      Herbert Xu authored
      commit 738ac1eb upstream.
      
      Shared skbs must not be modified and this is crucial for broadcast
      and/or multicast paths where we use it as an optimisation to avoid
      unnecessary cloning.
      
      The function skb_recv_datagram breaks this rule by setting peeked
      without cloning the skb first.  This causes funky races which leads
      to double-free.
      
      This patch fixes this by cloning the skb and replacing the skb
      in the list when setting skb->peeked.
      
      Fixes: a59322be ("[UDP]: Only increment counter on first peek/recv")
      Reported-by: default avatarKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      [bwh: Backported to 3.2: adjust context]
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      (cherry picked from commit 72e6f068)
      [wt: adjusted context for 2.6.32. Introduces a bug, see next commit]
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      52501955
    • Dan Carpenter's avatar
      rds: fix an integer overflow test in rds_info_getsockopt() · 4ad8ce65
      Dan Carpenter authored
      commit 468b732b upstream.
      
      "len" is a signed integer.  We check that len is not negative, so it
      goes from zero to INT_MAX.  PAGE_SIZE is unsigned long so the comparison
      is type promoted to unsigned long.  ULONG_MAX - 4095 is a higher than
      INT_MAX so the condition can never be true.
      
      I don't know if this is harmful but it seems safe to limit "len" to
      INT_MAX - 4095.
      
      Fixes: a8c879a7 ('RDS: Info and stats')
      Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      (cherry picked from commit f3a66bdc)
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      4ad8ce65
    • Mathias Nyman's avatar
      xhci: fix off by one error in TRB DMA address boundary check · 70397cf6
      Mathias Nyman authored
      commit 7895086a upstream.
      
      We need to check that a TRB is part of the current segment
      before calculating its DMA address.
      
      Previously a ring segment didn't use a full memory page, and every
      new ring segment got a new memory page, so the off by one
      error in checking the upper bound was never seen.
      
      Now that we use a full memory page, 256 TRBs (4096 bytes), the off by one
      didn't catch the case when a TRB was the first element of the next segment.
      
      This is triggered if the virtual memory pages for a ring segment are
      next to each in increasing order where the ring buffer wraps around and
      causes errors like:
      
      [  106.398223] xhci_hcd 0000:00:14.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 0 comp_code 1
      [  106.398230] xhci_hcd 0000:00:14.0: Looking for event-dma fffd3000 trb-start fffd4fd0 trb-end fffd5000 seg-start fffd4000 seg-end fffd4ff0
      
      The trb-end address is one outside the end-seg address.
      Tested-by: default avatarArkadiusz Miśkiewicz <arekm@maven.pl>
      Signed-off-by: default avatarMathias Nyman <mathias.nyman@linux.intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      (cherry picked from commit 6e3ae625)
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      70397cf6
    • Linus Torvalds's avatar
      Initialize msg/shm IPC objects before doing ipc_addid() · 81ced12a
      Linus Torvalds authored
      commit b9a53227 upstream.
      
      As reported by Dmitry Vyukov, we really shouldn't do ipc_addid() before
      having initialized the IPC object state.  Yes, we initialize the IPC
      object in a locked state, but with all the lockless RCU lookup work,
      that IPC object lock no longer means that the state cannot be seen.
      
      We already did this for the IPC semaphore code (see commit e8577d1f:
      "ipc/sem.c: fully initialize sem_array before making it visible") but we
      clearly forgot about msg and shm.
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Cc: Manfred Spraul <manfred@colorfullife.com>
      Cc: Davidlohr Bueso <dbueso@suse.de>
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      [bwh: Backported to 2.6.32:
       - Adjust context
       - The error path being moved looks a little different]
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      81ced12a
    • Manfred Spraul's avatar
      ipc/sem.c: fully initialize sem_array before making it visible · 424d5990
      Manfred Spraul authored
      commit e8577d1f upstream.
      
      ipc_addid() makes a new ipc identifier visible to everyone.  New objects
      start as locked, so that the caller can complete the initialization
      after the call.  Within struct sem_array, at least sma->sem_base and
      sma->sem_nsems are accessed without any locks, therefore this approach
      doesn't work.
      
      Thus: Move the ipc_addid() to the end of the initialization.
      Signed-off-by: default avatarManfred Spraul <manfred@colorfullife.com>
      Reported-by: default avatarRik van Riel <riel@redhat.com>
      Acked-by: default avatarRik van Riel <riel@redhat.com>
      Acked-by: default avatarDavidlohr Bueso <dave@stgolabs.net>
      Acked-by: default avatarRafael Aquini <aquini@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      [bwh: Backported to 2.6.32:
       - Adjust context
       - The error path being moved looks a little different]
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      424d5990
    • Johan Hovold's avatar
      USB: whiteheat: fix potential null-deref at probe · 86a283d3
      Johan Hovold authored
      commit cbb4be65 upstream.
      
      Fix potential null-pointer dereference at probe by making sure that the
      required endpoints are present.
      
      The whiteheat driver assumes there are at least five pairs of bulk
      endpoints, of which the final pair is used for the "command port". An
      attempt to bind to an interface with fewer bulk endpoints would
      currently lead to an oops.
      
      Fixes CVE-2015-5257.
      Reported-by: default avatarMoein Ghasemzadeh <moein@istuary.com>
      Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      86a283d3
    • Jason Wang's avatar
      virtio-net: drop NETIF_F_FRAGLIST · bce7c92e
      Jason Wang authored
      commit 48900cb6 upstream.
      
      virtio declares support for NETIF_F_FRAGLIST, but assumes
      that there are at most MAX_SKB_FRAGS + 2 fragments which isn't
      always true with a fraglist.
      
      A longer fraglist in the skb will make the call to skb_to_sgvec overflow
      the sg array, leading to memory corruption.
      
      Drop NETIF_F_FRAGLIST so we only get what we can handle.
      
      Cc: Michael S. Tsirkin <mst@redhat.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>
      [bwh: Backported to 2.6.32: there's only a single features field]
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      bce7c92e
    • Marcelo Leitner's avatar
      ipv6: addrconf: validate new MTU before applying it · 237dfc5b
      Marcelo Leitner authored
      commit 77751427 upstream.
      
      Currently we don't check if the new MTU is valid or not and this allows
      one to configure a smaller than minimum allowed by RFCs or even bigger
      than interface own MTU, which is a problem as it may lead to packet
      drops.
      
      If you have a daemon like NetworkManager running, this may be exploited
      by remote attackers by forging RA packets with an invalid MTU, possibly
      leading to a DoS. (NetworkManager currently only validates for values
      too small, but not for too big ones.)
      
      The fix is just to make sure the new value is valid. That is, between
      IPV6_MIN_MTU and interface's MTU.
      
      Note that similar check is already performed at
      ndisc_router_discovery(), for when kernel itself parses the RA.
      Signed-off-by: default avatarMarcelo Ricardo Leitner <mleitner@redhat.com>
      Signed-off-by: default avatarSabrina Dubroca <sd@queasysnail.net>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      [bwh: Backported to 2.6.32:
       - Add a strategy for the sysctl as we don't get a default strategy
       - Adjust context, spacing]
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      237dfc5b
    • Benjamin Randazzo's avatar
      md: use kzalloc() when bitmap is disabled · 37b602d2
      Benjamin Randazzo authored
      commit b6878d9e upstream.
      
      In drivers/md/md.c get_bitmap_file() uses kmalloc() for creating a
      mdu_bitmap_file_t called "file".
      
      5769         file = kmalloc(sizeof(*file), GFP_NOIO);
      5770         if (!file)
      5771                 return -ENOMEM;
      
      This structure is copied to user space at the end of the function.
      
      5786         if (err == 0 &&
      5787             copy_to_user(arg, file, sizeof(*file)))
      5788                 err = -EFAULT
      
      But if bitmap is disabled only the first byte of "file" is initialized
      with zero, so it's possible to read some bytes (up to 4095) of kernel
      space memory from user space. This is an information leak.
      
      5775         /* bitmap disabled, zero the first byte and copy out */
      5776         if (!mddev->bitmap_info.file)
      5777                 file->pathname[0] = '\0';
      Signed-off-by: default avatarBenjamin Randazzo <benjamin@randazzo.fr>
      Signed-off-by: default avatarNeilBrown <neilb@suse.com>
      [bwh: Backported to 2.6.32: patch both possible allocation calls]
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      37b602d2
    • Olga Kornievskaia's avatar
      Failing to send a CLOSE if file is opened WRONLY and server reboots on a 4.x mount · 88e77833
      Olga Kornievskaia authored
      commit a41cbe86 upstream.
      
      A test case is as the description says:
      open(foobar, O_WRONLY);
      sleep()  --> reboot the server
      close(foobar)
      
      The bug is because in nfs4state.c in nfs4_reclaim_open_state() a few
      line before going to restart, there is
      clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &state->flags).
      
      NFS4CLNT_RECLAIM_NOGRACE is a flag for the client states not open
      owner states. Value of NFS4CLNT_RECLAIM_NOGRACE is 4 which is the
      value of NFS_O_WRONLY_STATE in nfs4_state->flags. So clearing it wipes
      out state and when we go to close it, “call_close” doesn’t get set as
      state flag is not set and CLOSE doesn’t go on the wire.
      Signed-off-by: default avatarOlga Kornievskaia <aglo@umich.edu>
      Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      88e77833
    • Eric W. Biederman's avatar
      vfs: Test for and handle paths that are unreachable from their mnt_root · 44930ae4
      Eric W. Biederman authored
      commit 397d425d upstream.
      
      In rare cases a directory can be renamed out from under a bind mount.
      In those cases without special handling it becomes possible to walk up
      the directory tree to the root dentry of the filesystem and down
      from the root dentry to every other file or directory on the filesystem.
      
      Like division by zero .. from an unconnected path can not be given
      a useful semantic as there is no predicting at which path component
      the code will realize it is unconnected.  We certainly can not match
      the current behavior as the current behavior is a security hole.
      
      Therefore when encounting .. when following an unconnected path
      return -ENOENT.
      
      - Add a function path_connected to verify path->dentry is reachable
        from path->mnt.mnt_root.  AKA to validate that rename did not do
        something nasty to the bind mount.
      
        To avoid races path_connected must be called after following a path
        component to it's next path component.
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      44930ae4
    • Eric W. Biederman's avatar
      dcache: Handle escaped paths in prepend_path · fc9e08aa
      Eric W. Biederman authored
      commit cde93be4 upstream.
      
      A rename can result in a dentry that by walking up d_parent
      will never reach it's mnt_root.  For lack of a better term
      I call this an escaped path.
      
      prepend_path is called by four different functions __d_path,
      d_absolute_path, d_path, and getcwd.
      
      __d_path only wants to see paths are connected to the root it passes
      in.  So __d_path needs prepend_path to return an error.
      
      d_absolute_path similarly wants to see paths that are connected to
      some root.  Escaped paths are not connected to any mnt_root so
      d_absolute_path needs prepend_path to return an error greater
      than 1.  So escaped paths will be treated like paths on lazily
      unmounted mounts.
      
      getcwd needs to prepend "(unreachable)" so getcwd also needs
      prepend_path to return an error.
      
      d_path is the interesting hold out.  d_path just wants to print
      something, and does not care about the weird cases.  Which raises
      the question what should be printed?
      
      Given that <escaped_path>/<anything> should result in -ENOENT I
      believe it is desirable for escaped paths to be printed as empty
      paths.  As there are not really any meaninful path components when
      considered from the perspective of a mount tree.
      
      So tweak prepend_path to return an empty path with an new error
      code of 3 when it encounters an escaped path.
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      [bwh: For 2.6.32, implement the "(unreachable)" string in __d_path()]
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      fc9e08aa
  2. 18 Sep, 2015 25 commits