linux-stable.git/security, branch v5.4.78

selinux: Fix error return code in sel_ib_pkey_sid_slow()

2020-11-18T18:20:30+00:00

commit c350f8bea271782e2733419bd2ab9bf4ec2051ef upstream.

Fix to return a negative error code from the error handling case
instead of 0 in function sel_ib_pkey_sid_slow(), as done elsewhere
in this function.

Cc: stable@vger.kernel.org
Fixes: 409dcf31538a ("selinux: Add a cache for quicker retreival of PKey SIDs")
Reported-by: Hulk Robot 
Signed-off-by: Chen Zhou 
Signed-off-by: Paul Moore 
Signed-off-by: Greg Kroah-Hartman

evm: Check size of security.evm before using it

2020-11-01T11:01:05+00:00

commit 455b6c9112eff8d249e32ba165742085678a80a4 upstream.

This patch checks the size for the EVM_IMA_XATTR_DIGSIG and
EVM_XATTR_PORTABLE_DIGSIG types to ensure that the algorithm is read from
the buffer returned by vfs_getxattr_alloc().

Cc: stable@vger.kernel.org # 4.19.x
Fixes: 5feeb61183dde ("evm: Allow non-SHA1 digital signatures")
Signed-off-by: Roberto Sassu 
Signed-off-by: Mimi Zohar 
Signed-off-by: Greg Kroah-Hartman

ima: Don't ignore errors from crypto_shash_update()

2020-10-29T08:57:28+00:00

commit 60386b854008adc951c470067f90a2d85b5d520f upstream.

Errors returned by crypto_shash_update() are not checked in
ima_calc_boot_aggregate_tfm() and thus can be overwritten at the next
iteration of the loop. This patch adds a check after calling
crypto_shash_update() and returns immediately if the result is not zero.

Cc: stable@vger.kernel.org
Fixes: 3323eec921efd ("integrity: IMA as an integrity service provider")
Signed-off-by: Roberto Sassu 
Signed-off-by: Mimi Zohar 
Signed-off-by: Greg Kroah-Hartman

device_cgroup: Fix RCU list debugging warning

2020-10-01T11:18:13+00:00

[ Upstream commit bc62d68e2a0a69fcdcf28aca8edb01abf306b698 ]

exceptions may be traversed using list_for_each_entry_rcu()
outside of an RCU read side critical section BUT under the
protection of decgroup_mutex. Hence add the corresponding
lockdep expression to fix the following false-positive
warning:

[    2.304417] =============================
[    2.304418] WARNING: suspicious RCU usage
[    2.304420] 5.5.4-stable #17 Tainted: G            E
[    2.304422] -----------------------------
[    2.304424] security/device_cgroup.c:355 RCU-list traversed in non-reader section!!

Signed-off-by: Amol Grover 
Signed-off-by: James Morris 
Signed-off-by: Sasha Levin

selinux: sel_avc_get_stat_idx should increase position index

2020-10-01T11:17:32+00:00

[ Upstream commit 8d269a8e2a8f0bca89022f4ec98de460acb90365 ]

If seq_file .next function does not change position index,
read after some lseek can generate unexpected output.

$ dd if=/sys/fs/selinux/avc/cache_stats # usual output
lookups hits misses allocations reclaims frees
817223 810034 7189 7189 6992 7037
1934894 1926896 7998 7998 7632 7683
1322812 1317176 5636 5636 5456 5507
1560571 1551548 9023 9023 9056 9115
0+1 records in
0+1 records out
189 bytes copied, 5,1564e-05 s, 3,7 MB/s

$# read after lseek to midle of last line
$ dd if=/sys/fs/selinux/avc/cache_stats bs=180 skip=1
dd: /sys/fs/selinux/avc/cache_stats: cannot skip to specified offset
056 9115   <<<< end of last line
1560571 1551548 9023 9023 9056 9115  <<< whole last line once again
0+1 records in
0+1 records out
45 bytes copied, 8,7221e-05 s, 516 kB/s

$# read after lseek beyond  end of of file
$ dd if=/sys/fs/selinux/avc/cache_stats bs=1000 skip=1
dd: /sys/fs/selinux/avc/cache_stats: cannot skip to specified offset
1560571 1551548 9023 9023 9056 9115  <<<< generates whole last line
0+1 records in
0+1 records out
36 bytes copied, 9,0934e-05 s, 396 kB/s

https://bugzilla.kernel.org/show_bug.cgi?id=206283

Signed-off-by: Vasily Averin 
Acked-by: Stephen Smalley 
Signed-off-by: Paul Moore 
Signed-off-by: Sasha Levin

selinux: allow labeling before policy is loaded

2020-10-01T11:17:10+00:00

[ Upstream commit 3e3e24b42043eceb97ed834102c2d094dfd7aaa6 ]

Currently, the SELinux LSM prevents one from setting the
`security.selinux` xattr on an inode without a policy first being
loaded. However, this restriction is problematic: it makes it impossible
to have newly created files with the correct label before actually
loading the policy.

This is relevant in distributions like Fedora, where the policy is
loaded by systemd shortly after pivoting out of the initrd. In such
instances, all files created prior to pivoting will be unlabeled. One
then has to relabel them after pivoting, an operation which inherently
races with other processes trying to access those same files.

Going further, there are use cases for creating the entire root
filesystem on first boot from the initrd (e.g. Container Linux supports
this today[1], and we'd like to support it in Fedora CoreOS as well[2]).
One can imagine doing this in two ways: at the block device level (e.g.
laying down a disk image), or at the filesystem level. In the former,
labeling can simply be part of the image. But even in the latter
scenario, one still really wants to be able to set the right labels when
populating the new filesystem.

This patch enables this by changing behaviour in the following two ways:
1. allow `setxattr` if we're not initialized
2. don't try to set the in-core inode SID if we're not initialized;
   instead leave it as `LABEL_INVALID` so that revalidation may be
   attempted at a later time

Note the first hunk of this patch is mostly the same as a previously
discussed one[3], though it was part of a larger series which wasn't
accepted.

[1] https://coreos.com/os/docs/latest/root-filesystem-placement.html
[2] https://github.com/coreos/fedora-coreos-tracker/issues/94
[3] https://www.spinics.net/lists/linux-initramfs/msg04593.html

Co-developed-by: Victor Kamensky 
Signed-off-by: Victor Kamensky 
Signed-off-by: Jonathan Lebon 
Signed-off-by: Paul Moore 
Signed-off-by: Sasha Levin

Smack: prevent underflow in smk_set_cipso()

2020-08-19T06:16:16+00:00

[ Upstream commit 42a2df3e829f3c5562090391b33714b2e2e5ad4a ]

We have an upper bound on "maplevel" but forgot to check for negative
values.

Fixes: e114e473771c ("Smack: Simplified Mandatory Access Control Kernel")
Signed-off-by: Dan Carpenter 
Signed-off-by: Casey Schaufler 
Signed-off-by: Sasha Levin

Smack: fix another vsscanf out of bounds

2020-08-19T06:16:16+00:00

[ Upstream commit a6bd4f6d9b07452b0b19842044a6c3ea384b0b88 ]

This is similar to commit 84e99e58e8d1 ("Smack: slab-out-of-bounds in
vsscanf") where we added a bounds check on "rule".

Reported-by: syzbot+a22c6092d003d6fe1122@syzkaller.appspotmail.com
Fixes: f7112e6c9abf ("Smack: allow for significantly longer Smack labels v4")
Signed-off-by: Dan Carpenter 
Signed-off-by: Casey Schaufler 
Signed-off-by: Sasha Levin

ima: Have the LSM free its audit rule

2020-08-19T06:16:12+00:00

[ Upstream commit 9ff8a616dfab96a4fa0ddd36190907dc68886d9b ]

Ask the LSM to free its audit rule rather than directly calling kfree().
Both AppArmor and SELinux do additional work in their audit_rule_free()
hooks. Fix memory leaks by allowing the LSMs to perform necessary work.

Fixes: b16942455193 ("ima: use the lsm policy update notifier")
Signed-off-by: Tyler Hicks 
Cc: Janne Karhunen 
Cc: Casey Schaufler 
Reviewed-by: Mimi Zohar 
Signed-off-by: Mimi Zohar 
Signed-off-by: Sasha Levin

ima: move APPRAISE_BOOTPARAM dependency on ARCH_POLICY to runtime

2020-08-11T13:33:41+00:00

commit 311aa6aafea446c2f954cc19d66425bfed8c4b0b upstream.

The IMA_APPRAISE_BOOTPARAM config allows enabling different "ima_appraise="
modes - log, fix, enforce - at run time, but not when IMA architecture
specific policies are enabled.  This prevents properly labeling the
filesystem on systems where secure boot is supported, but not enabled on the
platform.  Only when secure boot is actually enabled should these IMA
appraise modes be disabled.

This patch removes the compile time dependency and makes it a runtime
decision, based on the secure boot state of that platform.

Test results as follows:

-> x86-64 with secure boot enabled

[    0.015637] Kernel command line: <...> ima_policy=appraise_tcb ima_appraise=fix
[    0.015668] ima: Secure boot enabled: ignoring ima_appraise=fix boot parameter option

-> powerpc with secure boot disabled

[    0.000000] Kernel command line: <...> ima_policy=appraise_tcb ima_appraise=fix
[    0.000000] Secure boot mode disabled

-> Running the system without secure boot and with both options set:

CONFIG_IMA_APPRAISE_BOOTPARAM=y
CONFIG_IMA_ARCH_POLICY=y

Audit prompts "missing-hash" but still allow execution and, consequently,
filesystem labeling:

type=INTEGRITY_DATA msg=audit(07/09/2020 12:30:27.778:1691) : pid=4976
uid=root auid=root ses=2
subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 op=appraise_data
cause=missing-hash comm=bash name=/usr/bin/evmctl dev="dm-0" ino=493150
res=no

Cc: stable@vger.kernel.org
Fixes: d958083a8f64 ("x86/ima: define arch_get_ima_policy() for x86")
Signed-off-by: Bruno Meneguele 
Cc: stable@vger.kernel.org # 5.0
Signed-off-by: Mimi Zohar 
Signed-off-by: Greg Kroah-Hartman