linux/security
Roberto Sassu 067a436b1b ima: Directly assign the ima_default_policy pointer to ima_rules
This patch prevents the following oops:

[   10.771813] BUG: kernel NULL pointer dereference, address: 0000000000000
[...]
[   10.779790] RIP: 0010:ima_match_policy+0xf7/0xb80
[...]
[   10.798576] Call Trace:
[   10.798993]  ? ima_lsm_policy_change+0x2b0/0x2b0
[   10.799753]  ? inode_init_owner+0x1a0/0x1a0
[   10.800484]  ? _raw_spin_lock+0x7a/0xd0
[   10.801592]  ima_must_appraise.part.0+0xb6/0xf0
[   10.802313]  ? ima_fix_xattr.isra.0+0xd0/0xd0
[   10.803167]  ima_must_appraise+0x4f/0x70
[   10.804004]  ima_post_path_mknod+0x2e/0x80
[   10.804800]  do_mknodat+0x396/0x3c0

It occurs when there is a failure during IMA initialization, and
ima_init_policy() is not called. IMA hooks still call ima_match_policy()
but ima_rules is NULL. This patch prevents the crash by directly assigning
the ima_default_policy pointer to ima_rules when ima_rules is defined. This
wouldn't alter the existing behavior, as ima_rules is always set at the end
of ima_init_policy().

Cc: stable@vger.kernel.org # 3.7.x
Fixes: 07f6a79415 ("ima: add appraise action keywords and default rules")
Reported-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-06-03 14:54:35 -04:00
..
apparmor .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
bpf bpf: lsm: Initialize the BPF LSM hooks 2020-03-30 01:34:00 +02:00
integrity ima: Directly assign the ima_default_policy pointer to ima_rules 2020-06-03 14:54:35 -04:00
keys keys: Fix proc_keys_next to increase position index 2020-04-16 10:10:50 -07:00
loadpin proc/sysctl: add shared variables for range check 2019-07-18 17:08:07 -07:00
lockdown security,lockdown,selinux: implement SELinux lockdown 2019-12-09 17:53:58 -05:00
safesetid security/safesetid: Replace rcu_swap_protected() with rcu_replace_pointer() 2019-10-30 08:45:57 -07:00
selinux selinux/stable-5.7 PR 20200416 2020-04-16 10:45:47 -07:00
smack Merge branch 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-02-08 13:26:41 -08:00
tomoyo .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
yama proc/sysctl: add shared variables for range check 2019-07-18 17:08:07 -07:00
commoncap.c Merge branch 'next-lsm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-07-09 12:24:21 -07:00
device_cgroup.c device_cgroup: Export devcgroup_check_permission 2019-10-07 15:11:38 -05:00
inode.c Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
Kconfig bpf: lsm: Initialize the BPF LSM hooks 2020-03-30 01:34:00 +02:00
Kconfig.hardening meminit fix 2019-07-28 12:33:15 -07:00
lsm_audit.c security,lockdown,selinux: implement SELinux lockdown 2019-12-09 17:53:58 -05:00
Makefile bpf: lsm: Initialize the BPF LSM hooks 2020-03-30 01:34:00 +02:00
min_addr.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
security.c ima: verify mprotect change is consistent with mmap policy 2020-05-22 14:41:04 -04:00