Skip to content

L
linux
Switch branch/tag
  1. 06 Feb, 2012 1 commit
    • Heiko Carstens's avatar
      exec: fix use-after-free bug in setup_new_exec() · 96e02d15
      Heiko Carstens authored 
      Setting the task name is done within setup_new_exec() by accessing
bprm->filename. However this happens after flush_old_exec().
This may result in a use after free bug, flush_old_exec() may
"complete" vfork_done, which will wake up the parent which in turn
may free the passed in filename.
To fix this add a new tcomm field in struct linux_binprm which
contains the now early generated task name until it is used.

Fixes this bug on s390:

  Unable to handle kernel pointer dereference at virtual kernel address 0000000039768000
  Process kworker/u:3 (pid: 245, task: 000000003a3dc840, ksp: 0000000039453818)
  Krnl PSW : 0704000180000000 0000000000282e94 (setup_new_exec+0xa0/0x374)
  Call Trace:
  ([<0000000000282e2c>] setup_new_exec+0x38/0x374)
   [<00000000002dd12e>] load_elf_binary+0x402/0x1bf4
   [<0000000000280a42>] search_binary_handler+0x38e/0x5bc
   [<0000000000282b6c>] do_execve_common+0x410/0x514
   [<0000000000282cb6>] do_execve+0x46/0x58
   [<00000000005bce58>] kernel_execve+0x28/0x70
   [<000000000014ba2e>] ____call_usermodehelper+0x102/0x140
   [<00000000005bc8da>] kernel_thread_starter+0x6/0xc
   [<00000000005bc8d4>] kernel_thread_starter+0x0/0xc
  Last Breaking-Event-Address:
   [<00000000002830f0>] setup_new_exec+0x2fc/0x374

  Kernel panic - not syncing: Fatal exception: panic_on_oops
Reported-by: default avatarSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      96e02d15
  3. 04 Feb, 2012 26 commits
  5. 03 Feb, 2012 4 commits
  7. 02 Feb, 2012 9 commits
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client · 6c073a7e
      Linus Torvalds authored 
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  rbd: fix safety of rbd_put_client()
  rbd: fix a memory leak in rbd_get_client()
  ceph: create a new session lock to avoid lock inversion
  ceph: fix length validation in parse_reply_info()
  ceph: initialize client debugfs outside of monc->mutex
  ceph: change "ceph.layout" xattr to be "ceph.file.layout"
      6c073a7e
    • Josh Triplett's avatar
      include/linux/lp8727.h: Remove executable bit · ff05f603
      Josh Triplett authored 
      Signed-off-by: default avatarJosh Triplett <josh@joshtriplett.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ff05f603
    • Alex Elder's avatar
      rbd: fix safety of rbd_put_client() · d23a4b3f
      Alex Elder authored 
      The rbd_client structure uses a kref to arrange for cleaning up and
freeing an instance when its last reference is dropped.  The cleanup
routine is rbd_client_release(), and one of the things it does is
delete the rbd_client from rbd_client_list.  It acquires node_lock
to do so, but the way it is done is still not safe.

The problem is that when attempting to reuse an existing rbd_client,
the structure found might already be in the process of getting
destroyed and cleaned up.

Here's the scenario, with "CLIENT" representing an existing
rbd_client that's involved in the race:

 Thread on CPU A                | Thread on CPU B
 ---------------                | ---------------
 rbd_put_client(CLIENT)         | rbd_get_client()
   kref_put()                   |   (acquires node_lock)
     kref->refcount becomes 0   |   __rbd_client_find() returns CLIENT
     calls rbd_client_release() |   kref_get(&CLIENT->kref);
                                |   (releases node_lock)
       (acquires node_lock)     |
       deletes CLIENT from list | ...and starts using CLIENT...
       (releases node_lock)     |
       and frees CLIENT         | <-- but CLIENT gets freed here

Fix this by having rbd_put_client() acquire node_lock.  The result
could still be improved, but at least it avoids this problem.
Signed-off-by: default avatarAlex Elder <elder@dreamhost.com>
Signed-off-by: default avatarSage Weil <sage@newdream.net>
      d23a4b3f
    • Christopher Yeoh's avatar
      Fix race in process_vm_rw_core · 8cdb878d
      Christopher Yeoh authored 
      This fixes the race in process_vm_core found by Oleg (see

  http://article.gmane.org/gmane.linux.kernel/1235667/

for details).

This has been updated since I last sent it as the creation of the new
mm_access() function did almost exactly the same thing as parts of the
previous version of this patch did.

In order to use mm_access() even when /proc isn't enabled, we move it to
kernel/fork.c where other related process mm access functions already
are.
Signed-off-by: default avatarChris Yeoh <yeohc@au1.ibm.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8cdb878d
    • Alex Elder's avatar
      rbd: fix a memory leak in rbd_get_client() · 97bb59a0
      Alex Elder authored 
      If an existing rbd client is found to be suitable for use in
rbd_get_client(), the rbd_options structure is not being
freed as it should.  Fix that.
Signed-off-by: default avatarAlex Elder <elder@dreamhost.com>
Signed-off-by: default avatarSage Weil <sage@newdream.net>
      97bb59a0
    • Alex Elder's avatar
      ceph: create a new session lock to avoid lock inversion · d8fb02ab
      Alex Elder authored 
      Lockdep was reporting a possible circular lock dependency in
dentry_lease_is_valid().  That function needs to sample the
session's s_cap_gen and and s_cap_ttl fields coherently, but needs
to do so while holding a dentry lock.  The s_cap_lock field was
being used to protect the two fields, but that can't be taken while
holding a lock on a dentry within the session.

In most cases, the s_cap_gen and s_cap_ttl fields only get operated
on separately.  But in three cases they need to be updated together.
Implement a new lock to protect the spots updating both fields
atomically is required.
Signed-off-by: default avatarAlex Elder <elder@dreamhost.com>
Reviewed-by: default avatarSage Weil <sage@newdream.net>
      d8fb02ab
    • Xi Wang's avatar
      ceph: fix length validation in parse_reply_info() · 32852a81
      Xi Wang authored 
      "len" is read from network and thus needs validation.  Otherwise, given
a bogus "len" value, p+len could be an out-of-bounds pointer, which is
used in further parsing.
Signed-off-by: default avatarXi Wang <xi.wang@gmail.com>
Signed-off-by: default avatarSage Weil <sage@newdream.net>
      32852a81
    • Sage Weil's avatar
      ceph: initialize client debugfs outside of monc->mutex · ab434b60
      Sage Weil authored 
      Initializing debufs under monc->mutex introduces a lock dependency for
sb->s_type->i_mutex_key, which (combined with several other dependencies)
leads to an annoying lockdep warning.  There's no particular reason to do
the debugfs setup under this lock, so move it out.

It used to be the case that our first monmap could come from the OSD; that
is no longer the case with recent servers, so we will reliably set up the
client entry during the initial authentication.

We don't have to worry about racing with debugfs teardown by
ceph_debugfs_client_cleanup() because ceph_destroy_client() calls
ceph_msgr_flush() first, which will wait for the message dispatch work
to complete (and the debugfs init to complete).

Fixes: #1940
Signed-off-by: default avatarSage Weil <sage@newdream.net>
      ab434b60
    • Alex Elder's avatar
      ceph: change "ceph.layout" xattr to be "ceph.file.layout" · 114fc474
      Alex Elder authored 
      The virtual extended attribute named "ceph.layout" is meaningful
only for regular files.  Change its name to be "ceph.file.layout" to
more directly reflect that in the ceph xattr namespace.  Preserve
the old "ceph.layout" name for the time being (until we decide it's
safe to get rid of it entirely).

Add a missing initializer for "readonly" in the terminating entry.
Signed-off-by: default avatarAlex Elder <elder@dreamhost.com>
Reviewed-by: default avatarSage Weil <sage@newdream.net>
      114fc474
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7