1. 12 2月, 2014 1 次提交
    • F
      flowcache: Make flow cache name space aware · ca925cf1
      Fan Du 提交于
      Inserting a entry into flowcache, or flushing flowcache should be based
      on per net scope. The reason to do so is flushing operation from fat
      netns crammed with flow entries will also making the slim netns with only
      a few flow cache entries go away in original implementation.
      
      Since flowcache is tightly coupled with IPsec, so it would be easier to
      put flow cache global parameters into xfrm namespace part. And one last
      thing needs to do is bumping flow cache genid, and flush flow cache should
      also be made in per net style.
      Signed-off-by: NFan Du <fan.du@windriver.com>
      Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
      ca925cf1
  2. 06 2月, 2014 2 次提交
    • S
      SELinux: Fix kernel BUG on empty security contexts. · 2172fa70
      Stephen Smalley 提交于
      Setting an empty security context (length=0) on a file will
      lead to incorrectly dereferencing the type and other fields
      of the security context structure, yielding a kernel BUG.
      As a zero-length security context is never valid, just reject
      all such security contexts whether coming from userspace
      via setxattr or coming from the filesystem upon a getxattr
      request by SELinux.
      
      Setting a security context value (empty or otherwise) unknown to
      SELinux in the first place is only possible for a root process
      (CAP_MAC_ADMIN), and, if running SELinux in enforcing mode, only
      if the corresponding SELinux mac_admin permission is also granted
      to the domain by policy.  In Fedora policies, this is only allowed for
      specific domains such as livecd for setting down security contexts
      that are not defined in the build host policy.
      
      Reproducer:
      su
      setenforce 0
      touch foo
      setfattr -n security.selinux foo
      
      Caveat:
      Relabeling or removing foo after doing the above may not be possible
      without booting with SELinux disabled.  Any subsequent access to foo
      after doing the above will also trigger the BUG.
      
      BUG output from Matthew Thode:
      [  473.893141] ------------[ cut here ]------------
      [  473.962110] kernel BUG at security/selinux/ss/services.c:654!
      [  473.995314] invalid opcode: 0000 [#6] SMP
      [  474.027196] Modules linked in:
      [  474.058118] CPU: 0 PID: 8138 Comm: ls Tainted: G      D   I
      3.13.0-grsec #1
      [  474.116637] Hardware name: Supermicro X8ST3/X8ST3, BIOS 2.0
      07/29/10
      [  474.149768] task: ffff8805f50cd010 ti: ffff8805f50cd488 task.ti:
      ffff8805f50cd488
      [  474.183707] RIP: 0010:[<ffffffff814681c7>]  [<ffffffff814681c7>]
      context_struct_compute_av+0xce/0x308
      [  474.219954] RSP: 0018:ffff8805c0ac3c38  EFLAGS: 00010246
      [  474.252253] RAX: 0000000000000000 RBX: ffff8805c0ac3d94 RCX:
      0000000000000100
      [  474.287018] RDX: ffff8805e8aac000 RSI: 00000000ffffffff RDI:
      ffff8805e8aaa000
      [  474.321199] RBP: ffff8805c0ac3cb8 R08: 0000000000000010 R09:
      0000000000000006
      [  474.357446] R10: 0000000000000000 R11: ffff8805c567a000 R12:
      0000000000000006
      [  474.419191] R13: ffff8805c2b74e88 R14: 00000000000001da R15:
      0000000000000000
      [  474.453816] FS:  00007f2e75220800(0000) GS:ffff88061fc00000(0000)
      knlGS:0000000000000000
      [  474.489254] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      [  474.522215] CR2: 00007f2e74716090 CR3: 00000005c085e000 CR4:
      00000000000207f0
      [  474.556058] Stack:
      [  474.584325]  ffff8805c0ac3c98 ffffffff811b549b ffff8805c0ac3c98
      ffff8805f1190a40
      [  474.618913]  ffff8805a6202f08 ffff8805c2b74e88 00068800d0464990
      ffff8805e8aac860
      [  474.653955]  ffff8805c0ac3cb8 000700068113833a ffff880606c75060
      ffff8805c0ac3d94
      [  474.690461] Call Trace:
      [  474.723779]  [<ffffffff811b549b>] ? lookup_fast+0x1cd/0x22a
      [  474.778049]  [<ffffffff81468824>] security_compute_av+0xf4/0x20b
      [  474.811398]  [<ffffffff8196f419>] avc_compute_av+0x2a/0x179
      [  474.843813]  [<ffffffff8145727b>] avc_has_perm+0x45/0xf4
      [  474.875694]  [<ffffffff81457d0e>] inode_has_perm+0x2a/0x31
      [  474.907370]  [<ffffffff81457e76>] selinux_inode_getattr+0x3c/0x3e
      [  474.938726]  [<ffffffff81455cf6>] security_inode_getattr+0x1b/0x22
      [  474.970036]  [<ffffffff811b057d>] vfs_getattr+0x19/0x2d
      [  475.000618]  [<ffffffff811b05e5>] vfs_fstatat+0x54/0x91
      [  475.030402]  [<ffffffff811b063b>] vfs_lstat+0x19/0x1b
      [  475.061097]  [<ffffffff811b077e>] SyS_newlstat+0x15/0x30
      [  475.094595]  [<ffffffff8113c5c1>] ? __audit_syscall_entry+0xa1/0xc3
      [  475.148405]  [<ffffffff8197791e>] system_call_fastpath+0x16/0x1b
      [  475.179201] Code: 00 48 85 c0 48 89 45 b8 75 02 0f 0b 48 8b 45 a0 48
      8b 3d 45 d0 b6 00 8b 40 08 89 c6 ff ce e8 d1 b0 06 00 48 85 c0 49 89 c7
      75 02 <0f> 0b 48 8b 45 b8 4c 8b 28 eb 1e 49 8d 7d 08 be 80 01 00 00 e8
      [  475.255884] RIP  [<ffffffff814681c7>]
      context_struct_compute_av+0xce/0x308
      [  475.296120]  RSP <ffff8805c0ac3c38>
      [  475.328734] ---[ end trace f076482e9d754adc ]---
      Reported-by: NMatthew Thode <mthode@mthode.org>
      Signed-off-by: NStephen Smalley <sds@tycho.nsa.gov>
      Cc: stable@vger.kernel.org
      Signed-off-by: NPaul Moore <pmoore@redhat.com>
      2172fa70
    • P
      selinux: add SOCK_DIAG_BY_FAMILY to the list of netlink message types · 6a96e150
      Paul Moore 提交于
      The SELinux AF_NETLINK/NETLINK_SOCK_DIAG socket class was missing the
      SOCK_DIAG_BY_FAMILY definition which caused SELINUX_ERR messages when
      the ss tool was run.
      
       # ss
       Netid  State  Recv-Q Send-Q  Local Address:Port   Peer Address:Port
       u_str  ESTAB  0      0                  * 14189             * 14190
       u_str  ESTAB  0      0                  * 14145             * 14144
       u_str  ESTAB  0      0                  * 14151             * 14150
       {...}
       # ausearch -m SELINUX_ERR
       ----
       time->Thu Jan 23 11:11:16 2014
       type=SYSCALL msg=audit(1390493476.445:374):
        arch=c000003e syscall=44 success=yes exit=40
        a0=3 a1=7fff03aa11f0 a2=28 a3=0 items=0 ppid=1852 pid=1895
        auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0
        tty=pts0 ses=1 comm="ss" exe="/usr/sbin/ss"
        subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
       type=SELINUX_ERR msg=audit(1390493476.445:374):
        SELinux:  unrecognized netlink message type=20 for sclass=32
      Signed-off-by: NPaul Moore <pmoore@redhat.com>
      6a96e150
  3. 05 2月, 2014 1 次提交
  4. 14 1月, 2014 2 次提交
  5. 12 1月, 2014 1 次提交
    • S
      SELinux: Fix possible NULL pointer dereference in selinux_inode_permission() · 3dc91d43
      Steven Rostedt 提交于
      While running stress tests on adding and deleting ftrace instances I hit
      this bug:
      
        BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
        IP: selinux_inode_permission+0x85/0x160
        PGD 63681067 PUD 7ddbe067 PMD 0
        Oops: 0000 [#1] PREEMPT
        CPU: 0 PID: 5634 Comm: ftrace-test-mki Not tainted 3.13.0-rc4-test-00033-gd2a6dde-dirty #20
        Hardware name:                  /DG965MQ, BIOS MQ96510J.86A.0372.2006.0605.1717 06/05/2006
        task: ffff880078375800 ti: ffff88007ddb0000 task.ti: ffff88007ddb0000
        RIP: 0010:[<ffffffff812d8bc5>]  [<ffffffff812d8bc5>] selinux_inode_permission+0x85/0x160
        RSP: 0018:ffff88007ddb1c48  EFLAGS: 00010246
        RAX: 0000000000000000 RBX: 0000000000800000 RCX: ffff88006dd43840
        RDX: 0000000000000001 RSI: 0000000000000081 RDI: ffff88006ee46000
        RBP: ffff88007ddb1c88 R08: 0000000000000000 R09: ffff88007ddb1c54
        R10: 6e6576652f6f6f66 R11: 0000000000000003 R12: 0000000000000000
        R13: 0000000000000081 R14: ffff88006ee46000 R15: 0000000000000000
        FS:  00007f217b5b6700(0000) GS:ffffffff81e21000(0000) knlGS:0000000000000000
        CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033^M
        CR2: 0000000000000020 CR3: 000000006a0fe000 CR4: 00000000000007f0
        Call Trace:
          security_inode_permission+0x1c/0x30
          __inode_permission+0x41/0xa0
          inode_permission+0x18/0x50
          link_path_walk+0x66/0x920
          path_openat+0xa6/0x6c0
          do_filp_open+0x43/0xa0
          do_sys_open+0x146/0x240
          SyS_open+0x1e/0x20
          system_call_fastpath+0x16/0x1b
        Code: 84 a1 00 00 00 81 e3 00 20 00 00 89 d8 83 c8 02 40 f6 c6 04 0f 45 d8 40 f6 c6 08 74 71 80 cf 02 49 8b 46 38 4c 8d 4d cc 45 31 c0 <0f> b7 50 20 8b 70 1c 48 8b 41 70 89 d9 8b 78 04 e8 36 cf ff ff
        RIP  selinux_inode_permission+0x85/0x160
        CR2: 0000000000000020
      
      Investigating, I found that the inode->i_security was NULL, and the
      dereference of it caused the oops.
      
      in selinux_inode_permission():
      
      	isec = inode->i_security;
      
      	rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0, &avd);
      
      Note, the crash came from stressing the deletion and reading of debugfs
      files.  I was not able to recreate this via normal files.  But I'm not
      sure they are safe.  It may just be that the race window is much harder
      to hit.
      
      What seems to have happened (and what I have traced), is the file is
      being opened at the same time the file or directory is being deleted.
      As the dentry and inode locks are not held during the path walk, nor is
      the inodes ref counts being incremented, there is nothing saving these
      structures from being discarded except for an rcu_read_lock().
      
      The rcu_read_lock() protects against freeing of the inode, but it does
      not protect freeing of the inode_security_struct.  Now if the freeing of
      the i_security happens with a call_rcu(), and the i_security field of
      the inode is not changed (it gets freed as the inode gets freed) then
      there will be no issue here.  (Linus Torvalds suggested not setting the
      field to NULL such that we do not need to check if it is NULL in the
      permission check).
      
      Note, this is a hack, but it fixes the problem at hand.  A real fix is
      to restructure the destroy_inode() to call all the destructor handlers
      from the RCU callback.  But that is a major job to do, and requires a
      lot of work.  For now, we just band-aid this bug with this fix (it
      works), and work on a more maintainable solution in the future.
      
      Link: http://lkml.kernel.org/r/20140109101932.0508dec7@gandalf.local.home
      Link: http://lkml.kernel.org/r/20140109182756.17abaaa8@gandalf.local.home
      
      Cc: stable@vger.kernel.org
      Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      3dc91d43
  6. 07 1月, 2014 1 次提交
    • T
      SELinux: Fix memory leak upon loading policy · 8ed81460
      Tetsuo Handa 提交于
      Hello.
      
      I got below leak with linux-3.10.0-54.0.1.el7.x86_64 .
      
      [  681.903890] kmemleak: 5538 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
      
      Below is a patch, but I don't know whether we need special handing for undoing
      ebitmap_set_bit() call.
      ----------
      >>From fe97527a90fe95e2239dfbaa7558f0ed559c0992 Mon Sep 17 00:00:00 2001
      From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
      Date: Mon, 6 Jan 2014 16:30:21 +0900
      Subject: [PATCH] SELinux: Fix memory leak upon loading policy
      
      Commit 2463c26d "SELinux: put name based create rules in a hashtable" did not
      check return value from hashtab_insert() in filename_trans_read(). It leaks
      memory if hashtab_insert() returns error.
      
        unreferenced object 0xffff88005c9160d0 (size 8):
          comm "systemd", pid 1, jiffies 4294688674 (age 235.265s)
          hex dump (first 8 bytes):
            57 0b 00 00 6b 6b 6b a5                          W...kkk.
          backtrace:
            [<ffffffff816604ae>] kmemleak_alloc+0x4e/0xb0
            [<ffffffff811cba5e>] kmem_cache_alloc_trace+0x12e/0x360
            [<ffffffff812aec5d>] policydb_read+0xd1d/0xf70
            [<ffffffff812b345c>] security_load_policy+0x6c/0x500
            [<ffffffff812a623c>] sel_write_load+0xac/0x750
            [<ffffffff811eb680>] vfs_write+0xc0/0x1f0
            [<ffffffff811ec08c>] SyS_write+0x4c/0xa0
            [<ffffffff81690419>] system_call_fastpath+0x16/0x1b
            [<ffffffffffffffff>] 0xffffffffffffffff
      
      However, we should not return EEXIST error to the caller, or the systemd will
      show below message and the boot sequence freezes.
      
        systemd[1]: Failed to load SELinux policy. Freezing.
      Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
      Acked-by: NEric Paris <eparis@redhat.com>
      Cc: stable@vger.kernel.org
      Signed-off-by: NPaul Moore <pmoore@redhat.com>
      8ed81460
  7. 03 1月, 2014 3 次提交
  8. 01 1月, 2014 2 次提交
    • C
      Smack: File receive audit correction · 4482a44f
      Casey Schaufler 提交于
      Eric Paris politely points out:
      
          Inside smack_file_receive() it seems like you are initting the audit
          field with LSM_AUDIT_DATA_TASK.  And then use
          smk_ad_setfield_u_fs_path().
      
          Seems like LSM_AUDIT_DATA_PATH would make more sense.  (and depending
          on how it's used fix a crash...)
      
      He is correct. This puts things in order.
      
      Targeted for git://git.gitorious.org/smack-next/kernel.gitSigned-off-by: NCasey Schaufler <casey@schaufler-ca.com>
      4482a44f
    • C
      Smack: Rationalize mount restrictions · 24ea1b6e
      Casey Schaufler 提交于
      The mount restrictions imposed by Smack rely heavily on the
      use of the filesystem "floor", which is the label that all
      processes writing to the filesystem must have access to. It
      turns out that while the "floor" notion is sound, it has yet
      to be fully implemented and has never been used.
      
      The sb_mount and sb_umount hooks only make sense if the
      filesystem floor is used actively, and it isn't. They can
      be reintroduced if a rational restriction comes up. Until
      then, they get removed.
      
      The sb_kern_mount hook is required for the option processing.
      It is too permissive in the case of unprivileged mounts,
      effectively bypassing the CAP_MAC_ADMIN restrictions if
      any of the smack options are specified. Unprivileged mounts
      are no longer allowed to set Smack filesystem options.
      Additionally, the root and default values are set to the
      label of the caller, in keeping with the policy that objects
      get the label of their creator.
      
      Targeted for git://git.gitorious.org/smack-next/kernel.gitSigned-off-by: NCasey Schaufler <casey@schaufler-ca.com>
      24ea1b6e
  9. 24 12月, 2013 4 次提交
  10. 20 12月, 2013 1 次提交
  11. 17 12月, 2013 2 次提交
  12. 16 12月, 2013 1 次提交
  13. 14 12月, 2013 1 次提交
    • P
      selinux: revert 102aefdd · 4d546f81
      Paul Moore 提交于
      Revert "selinux: consider filesystem subtype in policies"
      
      This reverts commit 102aefdd.
      
      Explanation from Eric Paris:
      
      	SELinux policy can specify if it should use a filesystem's
      	xattrs or not.  In current policy we have a specification that
      	fuse should not use xattrs but fuse.glusterfs should use
      	xattrs.  This patch has a bug in which non-glusterfs
      	filesystems would match the rule saying fuse.glusterfs should
      	use xattrs.  If both fuse and the particular filesystem in
      	question are not written to handle xattr calls during the mount
      	command, they will deadlock.
      
      	I have fixed the bug to do proper matching, however I believe a
      	revert is still the correct solution.  The reason I believe
      	that is because the code still does not work.  The s_subtype is
      	not set until after the SELinux hook which attempts to match on
      	the ".gluster" portion of the rule.  So we cannot match on the
      	rule in question.  The code is useless.
      Signed-off-by: NPaul Moore <pmoore@redhat.com>
      4d546f81
  14. 13 12月, 2013 4 次提交
  15. 12 12月, 2013 2 次提交
  16. 11 12月, 2013 1 次提交
  17. 10 12月, 2013 1 次提交
  18. 06 12月, 2013 1 次提交
    • T
      cgroup: replace cftype->read_seq_string() with cftype->seq_show() · 2da8ca82
      Tejun Heo 提交于
      In preparation of conversion to kernfs, cgroup file handling is
      updated so that it can be easily mapped to kernfs.  This patch
      replaces cftype->read_seq_string() with cftype->seq_show() which is
      not limited to single_open() operation and will map directcly to
      kernfs seq_file interface.
      
      The conversions are mechanical.  As ->seq_show() doesn't have @css and
      @cft, the functions which make use of them are converted to use
      seq_css() and seq_cft() respectively.  In several occassions, e.f. if
      it has seq_string in its name, the function name is updated to fit the
      new method better.
      
      This patch does not introduce any behavior changes.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NAristeu Rozanski <arozansk@redhat.com>
      Acked-by: NVivek Goyal <vgoyal@redhat.com>
      Acked-by: NMichal Hocko <mhocko@suse.cz>
      Acked-by: NDaniel Wagner <daniel.wagner@bmw-carit.de>
      Acked-by: NLi Zefan <lizefan@huawei.com>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Balbir Singh <bsingharora@gmail.com>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Neil Horman <nhorman@tuxdriver.com>
      2da8ca82
  19. 05 12月, 2013 5 次提交
  20. 03 12月, 2013 2 次提交
    • R
      ima: properly free ima_template_entry structures · a7ed7c60
      Roberto Sassu 提交于
      The new templates management mechanism records information associated
      to an event into an array of 'ima_field_data' structures and makes it
      available through the 'template_data' field of the 'ima_template_entry'
      structure (the element of the measurements list created by IMA).
      
      Since 'ima_field_data' contains dynamically allocated data (which length
      varies depending on the data associated to a selected template field),
      it is not enough to just free the memory reserved for a
      'ima_template_entry' structure if something goes wrong.
      
      This patch creates the new function ima_free_template_entry() which
      walks the array of 'ima_field_data' structures, frees the memory
      referenced by the 'data' pointer and finally the space reserved for
      the 'ima_template_entry' structure. Further, it replaces existing kfree()
      that have a pointer to an 'ima_template_entry' structure as argument
      with calls to the new function.
      
      Fixes: a71dc65d: ima: switch to new template management mechanism
      Signed-off-by: NRoberto Sassu <roberto.sassu@polito.it>
      Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
      a7ed7c60
    • C
      ima: Do not free 'entry' before it is initialized · 09ae6345
      Christoph Paasch 提交于
      7bc5f447 (ima: define new function ima_alloc_init_template() to
      API) moved the initialization of 'entry' in ima_add_boot_aggregate() a
      bit more below, after the if (ima_used_chip).
      
      So, 'entry' is not initialized while being inside this if-block. So, we
      should not attempt to free it.
      
      Found by Coverity (CID: 1131971)
      
      Fixes: 7bc5f447 (ima: define new function ima_alloc_init_template() to API)
      Signed-off-by: NChristoph Paasch <christoph.paasch@uclouvain.be>
      Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
      09ae6345
  21. 02 12月, 2013 2 次提交
    • E
      security: shmem: implement kernel private shmem inodes · c7277090
      Eric Paris 提交于
      We have a problem where the big_key key storage implementation uses a
      shmem backed inode to hold the key contents.  Because of this detail of
      implementation LSM checks are being done between processes trying to
      read the keys and the tmpfs backed inode.  The LSM checks are already
      being handled on the key interface level and should not be enforced at
      the inode level (since the inode is an implementation detail, not a
      part of the security model)
      
      This patch implements a new function shmem_kernel_file_setup() which
      returns the equivalent to shmem_file_setup() only the underlying inode
      has S_PRIVATE set.  This means that all LSM checks for the inode in
      question are skipped.  It should only be used for kernel internal
      operations where the inode is not exposed to userspace without proper
      LSM checking.  It is possible that some other users of
      shmem_file_setup() should use the new interface, but this has not been
      explored.
      
      Reproducing this bug is a little bit difficult.  The steps I used on
      Fedora are:
      
       (1) Turn off selinux enforcing:
      
      	setenforce 0
      
       (2) Create a huge key
      
      	k=`dd if=/dev/zero bs=8192 count=1 | keyctl padd big_key test-key @s`
      
       (3) Access the key in another context:
      
      	runcon system_u:system_r:httpd_t:s0-s0:c0.c1023 keyctl print $k >/dev/null
      
       (4) Examine the audit logs:
      
      	ausearch -m AVC -i --subject httpd_t | audit2allow
      
      If the last command's output includes a line that looks like:
      
      	allow httpd_t user_tmpfs_t:file { open read };
      
      There was an inode check between httpd and the tmpfs filesystem.  With
      this patch no such denial will be seen.  (NOTE! you should clear your
      audit log if you have tested for this previously)
      
      (Please return you box to enforcing)
      Signed-off-by: NEric Paris <eparis@redhat.com>
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      cc: Hugh Dickins <hughd@google.com>
      cc: linux-mm@kvack.org
      c7277090
    • D
      KEYS: Fix searching of nested keyrings · 9c5e45df
      David Howells 提交于
      If a keyring contains more than 16 keyrings (the capacity of a single node in
      the associative array) then those keyrings are split over multiple nodes
      arranged as a tree.
      
      If search_nested_keyrings() is called to search the keyring then it will
      attempt to manually walk over just the 0 branch of the associative array tree
      where all the keyring links are stored.  This works provided the key is found
      before the algorithm steps from one node containing keyrings to a child node
      or if there are sufficiently few keyring links that the keyrings are all in
      one node.
      
      However, if the algorithm does need to step from a node to a child node, it
      doesn't change the node pointer unless a shortcut also gets transited.  This
      means that the algorithm will keep scanning the same node over and over again
      without terminating and without returning.
      
      To fix this, move the internal-pointer-to-node translation from inside the
      shortcut transit handler so that it applies it to node arrival as well.
      
      This can be tested by:
      
      	r=`keyctl newring sandbox @s`
      	for ((i=0; i<=16; i++)); do keyctl newring ring$i $r; done
      	for ((i=0; i<=16; i++)); do keyctl add user a$i a %:ring$i; done
      	for ((i=0; i<=16; i++)); do keyctl search $r user a$i; done
      	for ((i=17; i<=20; i++)); do keyctl search $r user a$i; done
      
      The searches should all complete successfully (or with an error for 17-20),
      but instead one or more of them will hang.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Tested-by: NStephen Gallagher <sgallagh@redhat.com>
      9c5e45df