1. 24 Mar, 2016 13 commits
    • Jeff Vander Stoep's avatar
      pipe: iovec: Fix OOB read in pipe_read() · 972c638b
      Jeff Vander Stoep authored
      
      Previous upstream *stable* fix 14f81062 was incomplete.
      
      A local process can trigger a system crash with an OOB read on buf.
      This occurs when the state of buf gets out of sync. After an error in
      pipe_iov_copy_to_user() read_pipe may exit having updated buf->offset
      but not buf->len. Upon retrying pipe_read() while in
      pipe_iov_copy_to_user() *remaining will be larger than the space left
      after buf->offset e.g. *remaing = PAGE_SIZE, buf->len = PAGE_SIZE,
      buf->offset = 0x300.
      
      This is fixed by not updating the state of buf->offset until after the
      full copy is completed, similar to how pipe_write() is implemented.
      
      For stable kernels < 3.16.
      
      Bug: 27721803
      Change-Id: Iefffbcc6cfd159dba69c31bcd98c6d5c1f21ff2e
      Signed-off-by: default avatarJeff Vander Stoep <jeffv@google.com>
      972c638b
    • Mahesh A Saptasagar's avatar
      qcacld 2.0: Address buffer overflow due to invalid length · 243408ce
      Mahesh A Saptasagar authored
      
      prima to qcacld-2.0 propagation
      
      Check for valid length before copying the packet filter data from
      userspace buffer to kernel space buffer to avoid buffer overflow
      issue.
      
      Bug: 26754117
      Change-Id: I8d25a9d1b6909b6dda7a1d2aa80407ef2da821aa
      Signed-off-by: default avatarYuan Lin <yualin@google.com>
      243408ce
    • Mahesh A Saptasagar's avatar
      qcacld 2.0: Validate WPA and RSN IE for valid length · 34953f9f
      Mahesh A Saptasagar authored
      
      prima to qcacld-2.0 propagation
      
      Return failure to applications if genie ioctl is invoked to configure
      WPS/WPA/RSN IEs with arguments of improper length.
      
      Bug: 27104184
      Change-Id: I31e288db41e14b24be0e430afed3a5e360da1370
      Signed-off-by: default avatarYuan Lin <yualin@google.com>
      34953f9f
    • Mukul Sharma's avatar
      wlan:Check priviledge permission · 973503f0
      Mukul Sharma authored
      
      for CLEAR_MCBC_FILTER IOCTL
      
      Kernel assumes all SET IOCTL commands are assigned with even
      numbers. But in our WLAN driver, some SET IOCTLS are assigned with
      odd numbers. This leads kernel fail to check, for some SET IOCTLs,
      whether user has the right permission to do SET operation.
      Hence, in driver, before processing CLEAR_MCBC_FILTER IOCTL, making
      sure user task has right permission to process the command.
      
      Bug: 27104184
      Change-Id: I2332845fa6793dc63b6f397a9ebf53d37a52a7c7
      Signed-off-by: default avatarYuan Lin <yualin@google.com>
      973503f0
    • Mukul Sharma's avatar
      wlan:Check priviledge permission · aaf7476f
      Mukul Sharma authored
      
      for SET_POWER_PARAMS IOCTL
      
      Kernel assumes all SET IOCTL commands are assigned with even
      numbers. But in our WLAN driver, some SET IOCTLS are assigned with
      odd numbers. This leads kernel fail to check, for some SET IOCTLs,
      whether user has the right permission to do SET operation.
      Hence, in driver, before processing SET_POWER_PARAMS IOCTL, making
      sure user task has right permission to process the command.
      
      Bug: 27104184
      Change-Id: Iaab3d55c2acc75f65d6daf5998713cc9ff92a32c
      Signed-off-by: default avatarYuan Lin <yualin@google.com>
      aaf7476f
    • Mukul Sharma's avatar
      wlan:Check priviledge permission · ede034fd
      Mukul Sharma authored
      
      for SET_BAND_CONFIG IOCTL
      
      Kernel assumes all SET IOCTL commands are assigned with even
      numbers. But in our WLAN driver, some SET IOCTLS are assigned with
      odd numbers. This leads kernel fail to check, for some SET IOCTLs,
      whether user has the right permission to do SET operation.
      Hence, in driver, before processing SET_BAND_CONFIG IOCTL, making
      sure user task has right permission to process the command.
      
      Bug: 27104184
      Change-Id: I34e9d91f778b09eb73881aed5c6e3a10cbbd208c
      Signed-off-by: default avatarYuan Lin <yualin@google.com>
      ede034fd
    • Hanumantha Reddy Pothula's avatar
      wlan:Check priviledge permission · 4a75c965
      Hanumantha Reddy Pothula authored
      
      for SET_THREE_INT_GET_NONE
      
      Kernel assumes all SET IOCTL commands are assigned with even
      numbers. But in our WLAN driver, some SET IOCTLS are assigned with
      odd numbers. This leads kernel fail to check, for some SET IOCTLs,
      whether user has the right permission to do SET operation.
      Hence, in driver, before processing SET_THREE_INT_GET_NONE IOCTL,
      making sure user task has right permission to process the command.
      
      Bug: 27104184
      Change-Id: I8661872786adfb5492da505ba3960e62064ddd7e
      Signed-off-by: default avatarYuan Lin <yualin@google.com>
      4a75c965
    • Mukul Sharma's avatar
      wlan:Check priviledge permission · 86fd66a4
      Mukul Sharma authored
      
      for QCSAP_IOCTL_DISASSOC_STA
      
      Kernel assumes all SET IOCTL commands are assigned with even
      numbers. But in our WLAN driver, some SET IOCTLS are assigned with
      odd numbers. This leads kernel fail to check, for some SET IOCTLs,
      whether user has the right permission to do SET operation.
      Hence, in driver, before processing QCSAP_IOCTL_DISASSOC_STA IOCTL,
      making sure user task has right permission to process the command.
      
      Bug: 27104184
      Change-Id: I7928789c0ce94a2b81495064496766b9e62d6ed8
      Signed-off-by: default avatarYuan Lin <yualin@google.com>
      86fd66a4
    • Mukul Sharma's avatar
      wlan:Check priviledge permission · 518fd809
      Mukul Sharma authored
      
      for QCSAP_IOCTL_SETWPSIE
      
      Kernel assumes all SET IOCTL commands are assigned with even
      numbers. But in our WLAN driver, some SET IOCTLS are assigned with
      odd numbers. This leads kernel fail to check, for some SET IOCTLs,
      whether user has the right permission to do SET operation.
      Hence, in driver, before processing QCSAP_IOCTL_SETWPSIE IOCTL,
      making sure user task has right permission to process the command.
      
      Bug: 27104184
      Change-Id: I66acff95d6151b32f1cb3c36a164e1de021e1e30
      Signed-off-by: default avatarYuan Lin <yualin@google.com>
      518fd809
    • Mukul Sharma's avatar
      wlan:Check priviledge permission · fbb8f120
      Mukul Sharma authored
      
      for SET_VAR_INTS_GETNONE IOCTL
      
      Kernel assumes all SET IOCTL commands are assigned with even
      numbers. But in our WLAN driver, some SET IOCTLS are assigned with
      odd numbers. This leads kernel fail to check, for some SET IOCTLs,
      whether user has the right permission to do SET operation.
      Hence, in driver, before processing SET_VAR_INTS_GETNONE, making
      sure user task has right permission to process the command.
      
      Bug: 27104184
      Change-Id: Ia2465433aab6366160a167a62ca03e0ba720bcdb
      Signed-off-by: default avatarYuan Lin <yualin@google.com>
      fbb8f120
    • Mukul Sharma's avatar
      wlan:Check priviledge permission before processing · fd13b59e
      Mukul Sharma authored
      
      for SET_PACKET_FILTER IOCTL
      
      Kernel assumes all SET IOCTL commands are assigned with even
      numbers. But in our WLAN driver, some SET IOCTLS are assigned with
      odd numbers. This leads kernel fail to check, for some SET IOCTLs,
      whether user has the right permission to do SET operation.
      Hence, in driver, before processing SET_PACKET_FILTER IOCTL, making
      sure user task has right permission to process the command.
      
      Bug: 27104184
      Change-Id: I1edc65ee26c5e3e4260e0f6546434b0137493396
      Signed-off-by: default avatarYuan Lin <yualin@google.com>
      fd13b59e
    • Mukul Sharma's avatar
      wlan:Check priviledge permission before processing · e9dcd5aa
      Mukul Sharma authored
      
      for SET_CHAR_GET_NONE IOCTL
      
      Kernel assumes all SET IOCTL commands are assigned with even
      numbers. But in our WLAN driver, some SET IOCTLS are assigned with
      odd numbers. This leads kernel fail to check, for some SET IOCTLs,
      whether user has the right permission to do SET operation.
      Hence, in driver, before processing SET_CHAR_GET_NONE IOCTLs, making
      sure user task has right permission to process the command.
      
      Bug: 27104184
      Change-Id: Iccf25a9d1f1a7c13d3aaf2fc4bd3aebba740dbb2
      Signed-off-by: default avatarYuan Lin <yualin@google.com>
      e9dcd5aa
    • Mukul Sharma's avatar
      wlan:Check priviledge permission before processing · 1fac7333
      Mukul Sharma authored
      
      for SET_OEM_DATA_REQ IOCTL
      
      Kernel assumes all SET IOCTL commands are assigned with even
      numbers. But in our WLAN driver, some SET IOCTLS are assigned with
      odd numbers. This leads kernel fail to check, for some SET IOCTLs,
      whether user has the right permission to do SET operation.
      Hence, in driver, before processing SET_OEM_DATA_REQ IOCTLs, making
      sure user task has right permission to process the command.
      
      Bug: 27104184
      Change-Id: I651656fe11d4235232b76c972b5460b57e608449
      Signed-off-by: default avatarYuan Lin <yualin@google.com>
      1fac7333
  2. 22 Mar, 2016 1 commit
  3. 17 Mar, 2016 2 commits
    • Ben Hutchings's avatar
      pipe: iovec: Fix memory corruption when retrying atomic copy as non-atomic · eca06b45
      Ben Hutchings authored
      pipe_iov_copy_{from,to}_user() may be tried twice with the same iovec,
      the first time atomically and the second time not.  The second attempt
      needs to continue from the iovec position, pipe buffer offset and
      remaining length where the first attempt failed, but currently the
      pipe buffer offset and remaining length are reset.  This will corrupt
      the piped data (possibly also leading to an information leak between
      processes) and may also corrupt kernel memory.
      
      This was fixed upstream by commits f0d1bec9d58d ("new helper:
      copy_page_from_iter()") and 637b58c2887e ("switch pipe_read() to
      copy_page_to_iter()"), but those aren't suitable for stable.  This fix
      for older kernel versions was made by Seth Jennings for RHEL and I
      have extracted it from their update.
      
      CVE-2015-1805
      
      Bug: 27275324
      
      Change-Id: I459adb9076fcd50ff1f1c557089c4e421b036ec4
      References: https://bugzilla.redhat.com/show_bug.cgi?id=1202855
      
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      (cherry picked from commit 85c34d007116f8a8aafb173966a605fb03532f45)
      eca06b45
    • Patrick Tjin's avatar
      Keep history after reset to 094b859d · c97b5c0d
      Patrick Tjin authored
      c97b5c0d
  4. 24 Feb, 2016 1 commit
  5. 21 Jan, 2016 1 commit
    • Wish Wu's avatar
      msm: null pointer dereferencing · 094b859d
      Wish Wu authored
      
      Prevent unintended kernel NULL pointer dereferencing.
      
      Orignal code:
        hlist_del_rcu(&event->hlist_entry);
      
      Fix: Adding pointer check:
        if(!hlist_unhashed(&p_event->hlist_entry))
          hlist_del_rcu(&p_event->hlist_entry);
      
      Bug: 25364034
      Change-Id: Ieda6d8f4bb567827fa6c7709e9e729905c6c3882
      Signed-off-by: default avatarYuan Lin <yualin@google.com>
      094b859d
  6. 12 Jan, 2016 1 commit
  7. 08 Jan, 2016 1 commit
    • Vasily Kulikov's avatar
      include/linux/poison.h: fix LIST_POISON{1,2} offset · d965aca9
      Vasily Kulikov authored
      Poison pointer values should be small enough to find a room in
      non-mmap'able/hardly-mmap'able space.  E.g.  on x86 "poison pointer space"
      is located starting from 0x0.  Given unprivileged users cannot mmap
      anything below mmap_min_addr, it should be safe to use poison pointers
      lower than mmap_min_addr.
      
      The current poison pointer values of LIST_POISON{1,2} might be too big for
      mmap_min_addr values equal or less than 1 MB (common case, e.g.  Ubuntu
      uses only 0x10000).  There is little point to use such a big value given
      the "poison pointer space" below 1 MB is not yet exhausted.  Changing it
      to a smaller value solves the problem for small mmap_min_addr setups.
      
      The values are suggested by Solar Designer:
      http://www.openwall.com/lists/oss-security/2015/05/02/6
      
      
      
      Bug: 26186802
      Change-Id: Ie2121a417b6a43ee6d119c996b5ec2ad6d01a0a7
      Signed-off-by: default avatarYuan Lin <yualin@google.com>
      d965aca9
  8. 23 Oct, 2015 1 commit
  9. 22 Oct, 2015 1 commit
  10. 14 Oct, 2015 2 commits
    • Patrick Tjin's avatar
      msm: ipc_socket: fix leak of kernel memory to userspace · 4b3d11e7
      Patrick Tjin authored
      
      Limit the size of copy to the minimum of what was asked
      for or the number of results returned to prevent leaking of
      uninitialized kernel memory to userspace.
      
      Bug: 24157888
      Signed-off-by: default avatarPatrick Tjin <pattjin@google.com>
      Change-Id: I7433135ea3345905c053a81d0d759619b46c1430
      4b3d11e7
    • Patrick Tjin's avatar
      arm/configs: flo: Remove SysV IPC from kernel · bd8d871a
      Patrick Tjin authored
      
      System V IPCs are not compliant with Android's application lifecycle
      because allocated resources are not freeable by the low memory killer.
      This lead to global kernel resource leakage.
      
      For example, there is no way to automatically release a SysV
      semaphore allocated in the kernel when:
      - a buggy or malicious process exits
      - a non-buggy and non-malicious process crashes or is explicitly
        killed.
      
      Killing processes automatically to make room for new ones is an
      important part of Android's application lifecycle implementation.
      This means that, even assuming only non-buggy and non-malicious
      code, it is very likely that over time, the kernel global tables
      used to implement SysV IPCs will fill up.
      
      Bug: 24551430
      Bug: 22300191
      Signed-off-by: default avatarPatrick Tjin <pattjin@google.com>
      Change-Id: I98d592819974acbd5fb47d526ed1ce3700ae1bd5
      bd8d871a
  11. 17 Aug, 2015 1 commit
  12. 29 Jul, 2015 2 commits
    • Harshdeep Dhatt's avatar
      msm: kgsl: Increase the wait timeout for context detachment · 3bcea4ed
      Harshdeep Dhatt authored
      
      Increase the wait timeout for context detachment to 30s instead
      of 10s. Large IB's can take longer than 10s to retire and if a
      hang happens then recovering from the hang and completing the
      long IB's will take much longer than 10s, bump this timer to
      30s which should be sufficient for the context's commands to
      retire even if hang happens.
      
      Change-Id: I610186473208c574b0bcada0b62a7407ae171d37
      Signed-off-by: default avatarHarshdeep Dhatt <hdhatt@codeaurora.org>
      3bcea4ed
    • Erik Kline's avatar
      ipv6: sysctl to restrict candidate source addresses · ab98584a
      Erik Kline authored
      
      Per RFC 6724, section 4, "Candidate Source Addresses":
      
          It is RECOMMENDED that the candidate source addresses be the set
          of unicast addresses assigned to the interface that will be used
          to send to the destination (the "outgoing" interface).
      
      Add a sysctl to enable this behaviour.
      Signed-off-by: default avatarErik Kline <ek@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      
      [Simplified back-port of net-next 3985e8a3611a93bb36789f65db862e5700aab65e]
      
      Bug: 19470192
      Bug: 21832279
      Bug: 22464419
      Change-Id: Icd96382f814a6f3ea53f05beb98c266b1929c5a3
      ab98584a
  13. 25 Jul, 2015 1 commit
  14. 13 Jul, 2015 12 commits
    • Eric W. Biederman's avatar
      proc: Allow proc_free_inum to be called from any context · 381ca1fb
      Eric W. Biederman authored
      
      While testing the pid namespace code I hit this nasty warning.
      
      [  176.262617] ------------[ cut here ]------------
      [  176.263388] WARNING: at /home/eric/projects/linux/linux-userns-devel/kernel/softirq.c:160 local_bh_enable_ip+0x7a/0xa0()
      [  176.265145] Hardware name: Bochs
      [  176.265677] Modules linked in:
      [  176.266341] Pid: 742, comm: bash Not tainted 3.7.0userns+ #18
      [  176.266564] Call Trace:
      [  176.266564]  [<ffffffff810a539f>] warn_slowpath_common+0x7f/0xc0
      [  176.266564]  [<ffffffff810a53fa>] warn_slowpath_null+0x1a/0x20
      [  176.266564]  [<ffffffff810ad9ea>] local_bh_enable_ip+0x7a/0xa0
      [  176.266564]  [<ffffffff819308c9>] _raw_spin_unlock_bh+0x19/0x20
      [  176.266564]  [<ffffffff8123dbda>] proc_free_inum+0x3a/0x50
      [  176.266564]  [<ffffffff8111d0dc>] free_pid_ns+0x1c/0x80
      [  176.266564]  [<ffffffff8111d195>] put_pid_ns+0x35/0x50
      [  176.266564]  [<ffffffff810c608a>] put_pid+0x4a/0x60
      [  176.266564]  [<ffffffff8146b177>] tty_ioctl+0x717/0xc10
      [  176.266564]  [<ffffffff810aa4d5>] ? wait_consider_task+0x855/0xb90
      [  176.266564]  [<ffffffff81086bf9>] ? default_spin_lock_flags+0x9/0x10
      [  176.266564]  [<ffffffff810cab0a>] ? remove_wait_queue+0x5a/0x70
      [  176.266564]  [<ffffffff811e37e8>] do_vfs_ioctl+0x98/0x550
      [  176.266564]  [<ffffffff810b8a0f>] ? recalc_sigpending+0x1f/0x60
      [  176.266564]  [<ffffffff810b9127>] ? __set_task_blocked+0x37/0x80
      [  176.266564]  [<ffffffff810ab95b>] ? sys_wait4+0xab/0xf0
      [  176.266564]  [<ffffffff811e3d31>] sys_ioctl+0x91/0xb0
      [  176.266564]  [<ffffffff810a95f0>] ? task_stopped_code+0x50/0x50
      [  176.266564]  [<ffffffff81939199>] system_call_fastpath+0x16/0x1b
      [  176.266564] ---[ end trace 387af88219ad6143 ]---
      
      It turns out that spin_unlock_bh(proc_inum_lock) is not safe when
      put_pid is called with another spinlock held and irqs disabled.
      
      For now take the easy path and use spin_lock_irqsave(proc_inum_lock)
      in proc_free_inum and spin_loc_irq in proc_alloc_inum(proc_inum_lock).
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Bug: 22173056
      Backport: commits 0f7aa3c0
      
       to this one are backport of mnt namespace
      Signed-off-by: default avatarThierry Strudel <tstrudel@google.com>
      (cherry picked from commit dfb2ea45becb198beeb75350d0b7b7ad9076a38f)
      381ca1fb
    • Eric W. Biederman's avatar
      proc: Usable inode numbers for the namespace file descriptors. · 60e6a983
      Eric W. Biederman authored
      
      Assign a unique proc inode to each namespace, and use that
      inode number to ensure we only allocate at most one proc
      inode for every namespace in proc.
      
      A single proc inode per namespace allows userspace to test
      to see if two processes are in the same namespace.
      
      This has been a long requested feature and only blocked because
      a naive implementation would put the id in a global space and
      would ultimately require having a namespace for the names of
      namespaces, making migration and certain virtualization tricks
      impossible.
      
      We still don't have per superblock inode numbers for proc, which
      appears necessary for application unaware checkpoint/restart and
      migrations (if the application is using namespace file descriptors)
      but that is now allowd by the design if it becomes important.
      
      I have preallocated the ipc and uts initial proc inode numbers so
      their structures can be statically initialized.
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      (cherry picked from commit 98f842e675f96ffac96e6c50315790912b2812be)
      60e6a983
    • Eric W. Biederman's avatar
      proc: Fix the namespace inode permission checks. · dadd033b
      Eric W. Biederman authored
      
      Change the proc namespace files into symlinks so that
      we won't cache the dentries for the namespace files
      which can bypass the ptrace_may_access checks.
      
      To support the symlinks create an additional namespace
      inode with it's own set of operations distinct from the
      proc pid inode and dentry methods as those no longer
      make sense.
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      (cherry picked from commit bf056bfa80596a5d14b26b17276a56a0dcb080e5)
      dadd033b
    • Eric W. Biederman's avatar
      proc: Generalize proc inode allocation · 75140a91
      Eric W. Biederman authored
      
      Generalize the proc inode allocation so that it can be
      used without having to having to create a proc_dir_entry.
      
      This will allow namespace file descriptors to remain light
      weight entitities but still have the same inode number
      when the backing namespace is the same.
      Acked-by: default avatarSerge E. Hallyn <serge.hallyn@ubuntu.com>
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      (cherry picked from commit 33d6dce607573b5fd7a43168e0d91221b3ca532b)
      75140a91
    • Eric W. Biederman's avatar
      vfs: Allow unprivileged manipulation of the mount namespace. · 5fe7ef9b
      Eric W. Biederman authored
      
      - Add a filesystem flag to mark filesystems that are safe to mount as
        an unprivileged user.
      
      - Add a filesystem flag to mark filesystems that don't need MNT_NODEV
        when mounted by an unprivileged user.
      
      - Relax the permission checks to allow unprivileged users that have
        CAP_SYS_ADMIN permissions in the user namespace referred to by the
        current mount namespace to be allowed to mount, unmount, and move
        filesystems.
      Acked-by: default avatar"Serge E. Hallyn" <serge@hallyn.com>
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      (cherry picked from commit 0c55cfc4166d9a0f38de779bd4d75a90afbe7734)
      5fe7ef9b
    • Eric W. Biederman's avatar
      vfs: Only support slave subtrees across different user namespaces · 38d441be
      Eric W. Biederman authored
      
      Sharing mount subtress with mount namespaces created by unprivileged
      users allows unprivileged mounts created by unprivileged users to
      propagate to mount namespaces controlled by privileged users.
      
      Prevent nasty consequences by changing shared subtrees to slave
      subtress when an unprivileged users creates a new mount namespace.
      Acked-by: default avatarSerge Hallyn <serge.hallyn@canonical.com>
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      (cherry picked from commit 7a472ef4be8387bc05a42e16309b02c8ca943a40)
      38d441be
    • Eric W. Biederman's avatar
      vfs: Add a user namespace reference from struct mnt_namespace · 6f52736c
      Eric W. Biederman authored
      
      This will allow for support for unprivileged mounts in a new user namespace.
      Acked-by: default avatar"Serge E. Hallyn" <serge@hallyn.com>
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      (cherry picked from commit 771b1371686e0a63e938ada28de020b9a0040f55)
      6f52736c
    • Eric W. Biederman's avatar
      vfs: Add setns support for the mount namespace · cd0ed7c2
      Eric W. Biederman authored
      
      setns support for the mount namespace is a little tricky as an
      arbitrary decision must be made about what to set fs->root and
      fs->pwd to, as there is no expectation of a relationship between
      the two mount namespaces.  Therefore I arbitrarily find the root
      mount point, and follow every mount on top of it to find the top
      of the mount stack.  Then I set fs->root and fs->pwd to that
      location.  The topmost root of the mount stack seems like a
      reasonable place to be.
      
      Bind mount support for the mount namespace inodes has the
      possibility of creating circular dependencies between mount
      namespaces.  Circular dependencies can result in loops that
      prevent mount namespaces from every being freed.  I avoid
      creating those circular dependencies by adding a sequence number
      to the mount namespace and require all bind mounts be of a
      younger mount namespace into an older mount namespace.
      
      Add a helper function proc_ns_inode so it is possible to
      detect when we are attempting to bind mound a namespace inode.
      Acked-by: default avatarSerge Hallyn <serge.hallyn@canonical.com>
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      (cherry picked from commit 8823c079ba7136dc1948d6f6dcb5f8022bde438e)
      cd0ed7c2
    • Al Viro's avatar
      consitify do_mount() arguments · 5f453c9b
      Al Viro authored
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      (cherry picked from commit 808d4e3cfdcc52b19276175464f6dbca4df13b09)
      5f453c9b
    • Al Viro's avatar
      do_add_mount()/umount -l races · 57e87fa6
      Al Viro authored
      
      normally we deal with lock_mount()/umount races by checking that
      mountpoint to be is still in our namespace after lock_mount() has
      been done.  However, do_add_mount() skips that check when called
      with MNT_SHRINKABLE in flags (i.e. from finish_automount()).  The
      reason is that ->mnt_ns may be a temporary namespace created exactly
      to contain automounts a-la NFS4 referral handling.  It's not the
      namespace of the caller, though, so check_mnt() would fail here.
      We still need to check that ->mnt_ns is non-NULL in that case,
      though.
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      (cherry picked from commit 156cacb1d0d36b0d0582d9e798e58e0044f516b3)
      57e87fa6
    • Josef Bacik's avatar
      fs: introduce inode operation ->update_time · 32d9bbb0
      Josef Bacik authored
      
      Btrfs has to make sure we have space to allocate new blocks in order to modify
      the inode, so updating time can fail.  We've gotten around this by having our
      own file_update_time but this is kind of a pain, and Christoph has indicated he
      would like to make xfs do something different with atime updates.  So introduce
      ->update_time, where we will deal with i_version an a/m/c time updates and
      indicate which changes need to be made.  The normal version just does what it
      has always done, updates the time and marks the inode dirty, and then
      filesystems can choose to do something different.
      
      I've gone through all of the users of file_update_time and made them check for
      errors with the exception of the fault code since it's complicated and I wasn't
      quite sure what to do there, also Jan is going to be pushing the file time
      updates into page_mkwrite for those who have it so that should satisfy btrfs and
      make it not a big deal to check the file_update_time() return code in the
      generic fault path. Thanks,
      Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
      (cherry picked from commit c3b2da314834499f34cba94f7053e55f6d6f92d8)
      32d9bbb0
    • David Howells's avatar
      VFS: Comment mount following code · a6e63b05
      David Howells authored
      
      Add comments describing what the directions "up" and "down" mean and ref count
      handling to the VFS mount following family of functions.
      
      Signed-off-by: Valerie Aurora <vaurora@redhat.com> (Original author)
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      (cherry picked from commit f015f1267b23d3530d3f874243fb83cb5f443005)
      a6e63b05