This patch is based on an earlier patch by Eric Paris, he describes
the problem below:
"If an inode is accessed before policy load it will get placed on a
list of inodes to be initialized after policy load. After policy
load we call inode_doinit() which calls inode_doinit_with_dentry()
on all inodes accessed before policy load. In the case of inodes
in procfs that means we'll end up at the bottom where it does:
/* Default to the fs superblock SID. */
isec->sid = sbsec->sid;
if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) {
if (opt_dentry) {
isec->sclass = inode_mode_to_security_class(...)
rc = selinux_proc_get_sid(opt_dentry,
isec->sclass,
&sid);
if (rc)
goto out_unlock;
isec->sid = sid;
}
}
Since opt_dentry is null, we'll never call selinux_proc_get_sid()
and will leave the inode labeled with the label on the superblock.
I believe a fix would be to mimic the behavior of xattrs. Look
for an alias of the inode. If it can't be found, just leave the
inode uninitialized (and pick it up later) if it can be found, we
should be able to call selinux_proc_get_sid() ..."
On a system exhibiting this problem, you will notice a lot of files in
/proc with the generic "proc_t" type (at least the ones that were
accessed early in the boot), for example:
# ls -Z /proc/sys/kernel/shmmax | awk '{ print $4 " " $5 }'
system_u:object_r:proc_t:s0 /proc/sys/kernel/shmmax
However, with this patch in place we see the expected result:
# ls -Z /proc/sys/kernel/shmmax | awk '{ print $4 " " $5 }'
system_u:object_r:sysctl_kernel_t:s0 /proc/sys/kernel/shmmax
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Acked-by: Eric Paris <eparis@redhat.com>
It turns out that doing the SELinux MAC checks for mmap() before the
DAC checks was causing users and the SELinux policy folks headaches
as users were seeing a lot of SELinux AVC denials for the
memprotect:mmap_zero permission that would have also been denied by
the normal DAC capability checks (CAP_SYS_RAWIO).
Example:
# cat mmap_test.c
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <sys/mman.h>
int main(int argc, char *argv[])
{
int rc;
void *mem;
mem = mmap(0x0, 4096,
PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
if (mem == MAP_FAILED)
return errno;
printf("mem = %p\n", mem);
munmap(mem, 4096);
return 0;
}
# gcc -g -O0 -o mmap_test mmap_test.c
# ./mmap_test
mem = (nil)
# ausearch -m AVC | grep mmap_zero
type=AVC msg=audit(...): avc: denied { mmap_zero }
for pid=1025 comm="mmap_test"
scontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023
tcontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023
tclass=memprotect
This patch corrects things so that when the above example is run by a
user without CAP_SYS_RAWIO the SELinux AVC is no longer generated as
the DAC capability check fails before the SELinux permission check.
Signed-off-by: Paul Moore <pmoore@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Move the flags representing required permission to linux/key.h as the perm
parameter of security_key_permission() is in terms of them - and not the
permissions mask flags used in key->perm.
Whilst we're at it:
(1) Rename them to be KEY_NEED_xxx rather than KEY_xxx to avoid collisions
with symbols in uapi/linux/input.h.
(2) Don't use key_perm_t for a mask of required permissions, but rather limit
it to the permissions mask attached to the key and arguments related
directly to that.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
security_xfrm_policy_alloc can be called in atomic context so the
allocation should be done with GFP_ATOMIC. Add an argument to let the
callers choose the appropriate way. In order to do so a gfp argument
needs to be added to the method xfrm_policy_alloc_security in struct
security_operations and to the internal function
selinux_xfrm_alloc_user. After that switch to GFP_ATOMIC in the atomic
callers and leave GFP_KERNEL as before for the rest.
The path that needed the gfp argument addition is:
security_xfrm_policy_alloc -> security_ops.xfrm_policy_alloc_security ->
all users of xfrm_policy_alloc_security (e.g. selinux_xfrm_policy_alloc) ->
selinux_xfrm_alloc_user (here the allocation used to be GFP_KERNEL only)
Now adding a gfp argument to selinux_xfrm_alloc_user requires us to also
add it to security_context_to_sid which is used inside and prior to this
patch did only GFP_KERNEL allocation. So add gfp argument to
security_context_to_sid and adjust all of its callers as well.
CC: Paul Moore <paul@paul-moore.com>
CC: Dave Jones <davej@redhat.com>
CC: Steffen Klassert <steffen.klassert@secunet.com>
CC: Fan Du <fan.du@windriver.com>
CC: David S. Miller <davem@davemloft.net>
CC: LSM list <linux-security-module@vger.kernel.org>
CC: SELinux list <selinux@tycho.nsa.gov>
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
When writing policy via /sys/fs/selinux/policy I wrote the type and class
of filename trans rules in CPU endian instead of little endian. On
x86_64 this works just fine, but it means that on big endian arch's like
ppc64 and s390 userspace reads the policy and converts it from
le32_to_cpu. So the values are all screwed up. Write the values in le
format like it should have been to start.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
The usage of strict_strto*() is not preferred, because
strict_strto*() is obsolete. Thus, kstrto*() should be
used.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
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: Matthew Thode <mthode@mthode.org>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
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Merge tag 'v3.13' into stable-3.14
Linux 3.13
Conflicts:
security/selinux/hooks.c
Trivial merge issue in selinux_inet_conn_request() likely due to me
including patches that I sent to the stable folks in my next tree
resulting in the patch hitting twice (I think). Thankfully it was an
easy fix this time, but regardless, lesson learned, I will not do that
again.
Pull audit update from Eric Paris:
"Again we stayed pretty well contained inside the audit system.
Venturing out was fixing a couple of function prototypes which were
inconsistent (didn't hurt anything, but we used the same value as an
int, uint, u32, and I think even a long in a couple of places).
We also made a couple of minor changes to when a couple of LSMs called
the audit system. We hoped to add aarch64 audit support this go
round, but it wasn't ready.
I'm disappearing on vacation on Thursday. I should have internet
access, but it'll be spotty. If anything goes wrong please be sure to
cc rgb@redhat.com. He'll make fixing things his top priority"
* git://git.infradead.org/users/eparis/audit: (50 commits)
audit: whitespace fix in kernel-parameters.txt
audit: fix location of __net_initdata for audit_net_ops
audit: remove pr_info for every network namespace
audit: Modify a set of system calls in audit class definitions
audit: Convert int limit uses to u32
audit: Use more current logging style
audit: Use hex_byte_pack_upper
audit: correct a type mismatch in audit_syscall_exit()
audit: reorder AUDIT_TTY_SET arguments
audit: rework AUDIT_TTY_SET to only grab spin_lock once
audit: remove needless switch in AUDIT_SET
audit: use define's for audit version
audit: documentation of audit= kernel parameter
audit: wait_for_auditd rework for readability
audit: update MAINTAINERS
audit: log task info on feature change
audit: fix incorrect set of audit_sock
audit: print error message when fail to create audit socket
audit: fix dangling keywords in audit_log_set_loginuid() output
audit: log on errors from filter user rules
...
Pull security layer updates from James Morris:
"Changes for this kernel include maintenance updates for Smack, SELinux
(and several networking fixes), IMA and TPM"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (39 commits)
SELinux: Fix memory leak upon loading policy
tpm/tpm-sysfs: active_show() can be static
tpm: tpm_tis: Fix compile problems with CONFIG_PM_SLEEP/CONFIG_PNP
tpm: Make tpm-dev allocate a per-file structure
tpm: Use the ops structure instead of a copy in tpm_vendor_specific
tpm: Create a tpm_class_ops structure and use it in the drivers
tpm: Pull all driver sysfs code into tpm-sysfs.c
tpm: Move sysfs functions from tpm-interface to tpm-sysfs
tpm: Pull everything related to /dev/tpmX into tpm-dev.c
char: tpm: nuvoton: remove unused variable
tpm: MAINTAINERS: Cleanup TPM Maintainers file
tpm/tpm_i2c_atmel: fix coccinelle warnings
tpm/tpm_ibmvtpm: fix unreachable code warning (smatch warning)
tpm/tpm_i2c_stm_st33: Check return code of get_burstcount
tpm/tpm_ppi: Check return value of acpi_get_name
tpm/tpm_ppi: Do not compare strcmp(a,b) == -1
ima: remove unneeded size_limit argument from ima_eventdigest_init_common()
ima: update IMA-templates.txt documentation
ima: pass HASH_ALGO__LAST as hash algo in ima_eventdigest_init()
ima: change the default hash algorithm to SHA1 in ima_eventdigest_ng_init()
...
Two of the conditions in selinux_audit_rule_match() should never happen and
the third indicates a race that should be retried. Remove the calls to
audit_log() (which call audit_log_start()) and deal with the errors in the
caller, logging only once if the condition is met. Calling audit_log_start()
in this location makes buffer allocation and locking more complicated in the
calling tree (audit_filter_user()).
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
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: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Eric Paris <eparis@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
selinux_setprocattr() does ptrace_parent(p) under task_lock(p),
but task_struct->alloc_lock doesn't pin ->parent or ->ptrace,
this looks confusing and triggers the "suspicious RCU usage"
warning because ptrace_parent() does rcu_dereference_check().
And in theory this is wrong, spin_lock()->preempt_disable()
doesn't necessarily imply rcu_read_lock() we need to access
the ->parent.
Reported-by: Evan McNabb <emcnabb@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
Fix a broken networking check. Return an error if peer recv fails. If
secmark is active and the packet recv succeeds the peer recv error is
ignored.
Signed-off-by: Chad Hanson <chanson@trustedcs.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
selinux_setprocattr() does ptrace_parent(p) under task_lock(p),
but task_struct->alloc_lock doesn't pin ->parent or ->ptrace,
this looks confusing and triggers the "suspicious RCU usage"
warning because ptrace_parent() does rcu_dereference_check().
And in theory this is wrong, spin_lock()->preempt_disable()
doesn't necessarily imply rcu_read_lock() we need to access
the ->parent.
Reported-by: Evan McNabb <emcnabb@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
Pull SELinux fixes from James Morris.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
selinux: process labeled IPsec TCP SYN-ACK packets properly in selinux_ip_postroute()
selinux: look for IPsec labels on both inbound and outbound packets
selinux: handle TCP SYN-ACK packets correctly in selinux_ip_postroute()
selinux: handle TCP SYN-ACK packets correctly in selinux_ip_output()
selinux: fix possible memory leak
This reverts commit 102aefdda4.
Tom London reports that it causes sync() to hang on Fedora rawhide:
https://bugzilla.redhat.com/show_bug.cgi?id=1033965
and Josh Boyer bisected it down to this commit. Reverting the commit in
the rawhide kernel fixes the problem.
Eric Paris root-caused it to incorrect subtype matching in that commit
breaking fuse, and has a tentative patch, but by now we're better off
retrying this in 3.14 rather than playing with it any more.
Reported-by: Tom London <selinux@gmail.com>
Bisected-by: Josh Boyer <jwboyer@fedoraproject.org>
Acked-by: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Anand Avati <avati@redhat.com>
Cc: Paul Moore <paul@paul-moore.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Revert "selinux: consider filesystem subtype in policies"
This reverts commit 102aefdda4.
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: Paul Moore <pmoore@redhat.com>
Due to difficulty in arriving at the proper security label for
TCP SYN-ACK packets in selinux_ip_postroute(), we need to check packets
while/before they are undergoing XFRM transforms instead of waiting
until afterwards so that we can determine the correct security label.
Reported-by: Janak Desai <Janak.Desai@gtri.gatech.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
Previously selinux_skb_peerlbl_sid() would only check for labeled
IPsec security labels on inbound packets, this patch enables it to
check both inbound and outbound traffic for labeled IPsec security
labels.
Reported-by: Janak Desai <Janak.Desai@gtri.gatech.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
In selinux_ip_postroute() we perform access checks based on the
packet's security label. For locally generated traffic we get the
packet's security label from the associated socket; this works in all
cases except for TCP SYN-ACK packets. In the case of SYN-ACK packet's
the correct security label is stored in the connection's request_sock,
not the server's socket. Unfortunately, at the point in time when
selinux_ip_postroute() is called we can't query the request_sock
directly, we need to recreate the label using the same logic that
originally labeled the associated request_sock.
See the inline comments for more explanation.
Reported-by: Janak Desai <Janak.Desai@gtri.gatech.edu>
Tested-by: Janak Desai <Janak.Desai@gtri.gatech.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
In selinux_ip_output() we always label packets based on the parent
socket. While this approach works in almost all cases, it doesn't
work in the case of TCP SYN-ACK packets when the correct label is not
the label of the parent socket, but rather the label of the larval
socket represented by the request_sock struct.
Unfortunately, since the request_sock isn't queued on the parent
socket until *after* the SYN-ACK packet is sent, we can't lookup the
request_sock to determine the correct label for the packet; at this
point in time the best we can do is simply pass/NF_ACCEPT the packet.
It must be said that simply passing the packet without any explicit
labeling action, while far from ideal, is not terrible as the SYN-ACK
packet will inherit any IP option based labeling from the initial
connection request so the label *should* be correct and all our
access controls remain in place so we shouldn't have to worry about
information leaks.
Reported-by: Janak Desai <Janak.Desai@gtri.gatech.edu>
Tested-by: Janak Desai <Janak.Desai@gtri.gatech.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
Fix a broken networking check. Return an error if peer recv fails. If
secmark is active and the packet recv succeeds the peer recv error is
ignored.
Signed-off-by: Chad Hanson <chanson@trustedcs.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Due to difficulty in arriving at the proper security label for
TCP SYN-ACK packets in selinux_ip_postroute(), we need to check packets
while/before they are undergoing XFRM transforms instead of waiting
until afterwards so that we can determine the correct security label.
Reported-by: Janak Desai <Janak.Desai@gtri.gatech.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
Previously selinux_skb_peerlbl_sid() would only check for labeled
IPsec security labels on inbound packets, this patch enables it to
check both inbound and outbound traffic for labeled IPsec security
labels.
Reported-by: Janak Desai <Janak.Desai@gtri.gatech.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
We don't need to inspect the packet to determine if the packet is an
IPv4 packet arriving on an IPv6 socket when we can query the
request_sock directly.
Signed-off-by: Paul Moore <pmoore@redhat.com>
In selinux_netlbl_skbuff_setsid() we leverage a cached NetLabel
secattr whenever possible. However, we never check to ensure that
the desired SID matches the cached NetLabel secattr. This patch
checks the SID against the secattr before use and only uses the
cached secattr when the SID values match.
Signed-off-by: Paul Moore <pmoore@redhat.com>
In selinux_ip_postroute() we perform access checks based on the
packet's security label. For locally generated traffic we get the
packet's security label from the associated socket; this works in all
cases except for TCP SYN-ACK packets. In the case of SYN-ACK packet's
the correct security label is stored in the connection's request_sock,
not the server's socket. Unfortunately, at the point in time when
selinux_ip_postroute() is called we can't query the request_sock
directly, we need to recreate the label using the same logic that
originally labeled the associated request_sock.
See the inline comments for more explanation.
Reported-by: Janak Desai <Janak.Desai@gtri.gatech.edu>
Tested-by: Janak Desai <Janak.Desai@gtri.gatech.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
In selinux_ip_output() we always label packets based on the parent
socket. While this approach works in almost all cases, it doesn't
work in the case of TCP SYN-ACK packets when the correct label is not
the label of the parent socket, but rather the label of the larval
socket represented by the request_sock struct.
Unfortunately, since the request_sock isn't queued on the parent
socket until *after* the SYN-ACK packet is sent, we can't lookup the
request_sock to determine the correct label for the packet; at this
point in time the best we can do is simply pass/NF_ACCEPT the packet.
It must be said that simply passing the packet without any explicit
labeling action, while far from ideal, is not terrible as the SYN-ACK
packet will inherit any IP option based labeling from the initial
connection request so the label *should* be correct and all our
access controls remain in place so we shouldn't have to worry about
information leaks.
Reported-by: Janak Desai <Janak.Desai@gtri.gatech.edu>
Tested-by: Janak Desai <Janak.Desai@gtri.gatech.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
Free 'ctx_str' when necessary.
Signed-off-by: Geyslan G. Bem <geyslan@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
Pull security subsystem updates from James Morris:
"In this patchset, we finally get an SELinux update, with Paul Moore
taking over as maintainer of that code.
Also a significant update for the Keys subsystem, as well as
maintenance updates to Smack, IMA, TPM, and Apparmor"
and since I wanted to know more about the updates to key handling,
here's the explanation from David Howells on that:
"Okay. There are a number of separate bits. I'll go over the big bits
and the odd important other bit, most of the smaller bits are just
fixes and cleanups. If you want the small bits accounting for, I can
do that too.
(1) Keyring capacity expansion.
KEYS: Consolidate the concept of an 'index key' for key access
KEYS: Introduce a search context structure
KEYS: Search for auth-key by name rather than target key ID
Add a generic associative array implementation.
KEYS: Expand the capacity of a keyring
Several of the patches are providing an expansion of the capacity of a
keyring. Currently, the maximum size of a keyring payload is one page.
Subtract a small header and then divide up into pointers, that only gives
you ~500 pointers on an x86_64 box. However, since the NFS idmapper uses
a keyring to store ID mapping data, that has proven to be insufficient to
the cause.
Whatever data structure I use to handle the keyring payload, it can only
store pointers to keys, not the keys themselves because several keyrings
may point to a single key. This precludes inserting, say, and rb_node
struct into the key struct for this purpose.
I could make an rbtree of records such that each record has an rb_node
and a key pointer, but that would use four words of space per key stored
in the keyring. It would, however, be able to use much existing code.
I selected instead a non-rebalancing radix-tree type approach as that
could have a better space-used/key-pointer ratio. I could have used the
radix tree implementation that we already have and insert keys into it by
their serial numbers, but that means any sort of search must iterate over
the whole radix tree. Further, its nodes are a bit on the capacious side
for what I want - especially given that key serial numbers are randomly
allocated, thus leaving a lot of empty space in the tree.
So what I have is an associative array that internally is a radix-tree
with 16 pointers per node where the index key is constructed from the key
type pointer and the key description. This means that an exact lookup by
type+description is very fast as this tells us how to navigate directly to
the target key.
I made the data structure general in lib/assoc_array.c as far as it is
concerned, its index key is just a sequence of bits that leads to a
pointer. It's possible that someone else will be able to make use of it
also. FS-Cache might, for example.
(2) Mark keys as 'trusted' and keyrings as 'trusted only'.
KEYS: verify a certificate is signed by a 'trusted' key
KEYS: Make the system 'trusted' keyring viewable by userspace
KEYS: Add a 'trusted' flag and a 'trusted only' flag
KEYS: Separate the kernel signature checking keyring from module signing
These patches allow keys carrying asymmetric public keys to be marked as
being 'trusted' and allow keyrings to be marked as only permitting the
addition or linkage of trusted keys.
Keys loaded from hardware during kernel boot or compiled into the kernel
during build are marked as being trusted automatically. New keys can be
loaded at runtime with add_key(). They are checked against the system
keyring contents and if their signatures can be validated with keys that
are already marked trusted, then they are marked trusted also and can
thus be added into the master keyring.
Patches from Mimi Zohar make this usable with the IMA keyrings also.
(3) Remove the date checks on the key used to validate a module signature.
X.509: Remove certificate date checks
It's not reasonable to reject a signature just because the key that it was
generated with is no longer valid datewise - especially if the kernel
hasn't yet managed to set the system clock when the first module is
loaded - so just remove those checks.
(4) Make it simpler to deal with additional X.509 being loaded into the kernel.
KEYS: Load *.x509 files into kernel keyring
KEYS: Have make canonicalise the paths of the X.509 certs better to deduplicate
The builder of the kernel now just places files with the extension ".x509"
into the kernel source or build trees and they're concatenated by the
kernel build and stuffed into the appropriate section.
(5) Add support for userspace kerberos to use keyrings.
KEYS: Add per-user_namespace registers for persistent per-UID kerberos caches
KEYS: Implement a big key type that can save to tmpfs
Fedora went to, by default, storing kerberos tickets and tokens in tmpfs.
We looked at storing it in keyrings instead as that confers certain
advantages such as tickets being automatically deleted after a certain
amount of time and the ability for the kernel to get at these tokens more
easily.
To make this work, two things were needed:
(a) A way for the tickets to persist beyond the lifetime of all a user's
sessions so that cron-driven processes can still use them.
The problem is that a user's session keyrings are deleted when the
session that spawned them logs out and the user's user keyring is
deleted when the UID is deleted (typically when the last log out
happens), so neither of these places is suitable.
I've added a system keyring into which a 'persistent' keyring is
created for each UID on request. Each time a user requests their
persistent keyring, the expiry time on it is set anew. If the user
doesn't ask for it for, say, three days, the keyring is automatically
expired and garbage collected using the existing gc. All the kerberos
tokens it held are then also gc'd.
(b) A key type that can hold really big tickets (up to 1MB in size).
The problem is that Active Directory can return huge tickets with lots
of auxiliary data attached. We don't, however, want to eat up huge
tracts of unswappable kernel space for this, so if the ticket is
greater than a certain size, we create a swappable shmem file and dump
the contents in there and just live with the fact we then have an
inode and a dentry overhead. If the ticket is smaller than that, we
slap it in a kmalloc()'d buffer"
* 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (121 commits)
KEYS: Fix keyring content gc scanner
KEYS: Fix error handling in big_key instantiation
KEYS: Fix UID check in keyctl_get_persistent()
KEYS: The RSA public key algorithm needs to select MPILIB
ima: define '_ima' as a builtin 'trusted' keyring
ima: extend the measurement list to include the file signature
kernel/system_certificate.S: use real contents instead of macro GLOBAL()
KEYS: fix error return code in big_key_instantiate()
KEYS: Fix keyring quota misaccounting on key replacement and unlink
KEYS: Fix a race between negating a key and reading the error set
KEYS: Make BIG_KEYS boolean
apparmor: remove the "task" arg from may_change_ptraced_domain()
apparmor: remove parent task info from audit logging
apparmor: remove tsk field from the apparmor_audit_struct
apparmor: fix capability to not use the current task, during reporting
Smack: Ptrace access check mode
ima: provide hash algo info in the xattr
ima: enable support for larger default filedata hash algorithms
ima: define kernel parameter 'ima_template=' to change configured default
ima: add Kconfig default measurement list template
...
Pull audit updates from Eric Paris:
"Nothing amazing. Formatting, small bug fixes, couple of fixes where
we didn't get records due to some old VFS changes, and a change to how
we collect execve info..."
Fixed conflict in fs/exec.c as per Eric and linux-next.
* git://git.infradead.org/users/eparis/audit: (28 commits)
audit: fix type of sessionid in audit_set_loginuid()
audit: call audit_bprm() only once to add AUDIT_EXECVE information
audit: move audit_aux_data_execve contents into audit_context union
audit: remove unused envc member of audit_aux_data_execve
audit: Kill the unused struct audit_aux_data_capset
audit: do not reject all AUDIT_INODE filter types
audit: suppress stock memalloc failure warnings since already managed
audit: log the audit_names record type
audit: add child record before the create to handle case where create fails
audit: use given values in tty_audit enable api
audit: use nlmsg_len() to get message payload length
audit: use memset instead of trying to initialize field by field
audit: fix info leak in AUDIT_GET requests
audit: update AUDIT_INODE filter rule to comparator function
audit: audit feature to set loginuid immutable
audit: audit feature to only allow unsetting the loginuid
audit: allow unsetting the loginuid (with priv)
audit: remove CONFIG_AUDIT_LOGINUID_IMMUTABLE
audit: loginuid functions coding style
selinux: apply selinux checks on new audit message types
...
Dynamically allocate a couple of the larger stack variables in order to
reduce the stack footprint below 1024. gcc-4.8
security/selinux/ss/services.c: In function 'security_load_policy':
security/selinux/ss/services.c:1964:1: warning: the frame size of 1104 bytes is larger than 1024 bytes [-Wframe-larger-than=]
}
Also silence a couple of checkpatch warnings at the same time.
WARNING: sizeof policydb should be sizeof(policydb)
+ memcpy(oldpolicydb, &policydb, sizeof policydb);
WARNING: sizeof policydb should be sizeof(policydb)
+ memcpy(&policydb, newpolicydb, sizeof policydb);
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Eric Paris <eparis@parisplace.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Update the policy version (POLICYDB_VERSION_CONSTRAINT_NAMES) to allow
holding of policy source info for constraints.
Signed-off-by: Richard Haines <richard_c_haines@btinternet.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>
We use the read check to get the feature set (like AUDIT_GET) and the
write check to set the features (like AUDIT_SET).
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Conflicts:
drivers/net/usb/qmi_wwan.c
include/net/dst.h
Trivial merge conflicts, both were overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
