linux-toradex.git/security, branch v5.17-rc4

Merge tag 'integrity-v5.17-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

2022-02-07T17:55:14+00:00

Pull integrity fixes from Mimi Zohar:
 "Fixes for recently found bugs.

  One was found/noticed while reviewing IMA support for fsverity digests
  and signatures. Two of them were found/noticed while working on IMA
  namespacing. Plus two other bugs.

  All of them are for previous kernel releases"

* tag 'integrity-v5.17-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  ima: Do not print policy rule with inactive LSM labels
  ima: Allow template selection with ima_template[_fmt]= after ima_hash=
  ima: Remove ima_policy file before directory
  integrity: check the return value of audit_log_start()
  ima: fix reference leak in asymmetric_verify()

Merge tag 'selinux-pr-20220203' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

2022-02-04T00:44:12+00:00

Pull selinux fix from Paul Moore:
 "One small SELinux patch to ensure that a policy structure field is
  properly reset after freeing so that we don't inadvertently do a
  double-free on certain error conditions"

* tag 'selinux-pr-20220203' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: fix double free of cond_list on error paths

ima: Do not print policy rule with inactive LSM labels

2022-02-02T16:59:54+00:00

Before printing a policy rule scan for inactive LSM labels in the policy
rule. Inactive LSM labels are identified by args_p != NULL and
rule == NULL.

Fixes: 483ec26eed42 ("ima: ima/lsm policy rule loading logic bug fixes")
Signed-off-by: Stefan Berger 
Cc:  # v5.6+
Acked-by: Christian Brauner 
[zohar@linux.ibm.com: Updated "Fixes" tag]
Signed-off-by: Mimi Zohar

ima: Allow template selection with ima_template[_fmt]= after ima_hash=

2022-02-02T16:59:54+00:00

Commit c2426d2ad5027 ("ima: added support for new kernel cmdline parameter
ima_template_fmt") introduced an additional check on the ima_template
variable to avoid multiple template selection.

Unfortunately, ima_template could be also set by the setup function of the
ima_hash= parameter, when it calls ima_template_desc_current(). This causes
attempts to choose a new template with ima_template= or with
ima_template_fmt=, after ima_hash=, to be ignored.

Achieve the goal of the commit mentioned with the new static variable
template_setup_done, so that template selection requests after ima_hash=
are not ignored.

Finally, call ima_init_template_list(), if not already done, to initialize
the list of templates before lookup_template_desc() is called.

Reported-by: Guo Zihua 
Signed-off-by: Roberto Sassu 
Cc: stable@vger.kernel.org
Fixes: c2426d2ad5027 ("ima: added support for new kernel cmdline parameter ima_template_fmt")
Signed-off-by: Mimi Zohar

ima: Remove ima_policy file before directory

2022-02-02T16:59:09+00:00

The removal of ima_dir currently fails since ima_policy still exists, so
remove the ima_policy file before removing the directory.

Fixes: 4af4662fa4a9 ("integrity: IMA policy")
Signed-off-by: Stefan Berger 
Cc: 
Acked-by: Christian Brauner 
Signed-off-by: Mimi Zohar

integrity: check the return value of audit_log_start()

2022-02-02T16:44:23+00:00

audit_log_start() returns audit_buffer pointer on success or NULL on
error, so it is better to check the return value of it.

Fixes: 3323eec921ef ("integrity: IMA as an integrity service provider")
Signed-off-by: Xiaoke Wang 
Cc: 
Reviewed-by: Paul Moore 
Signed-off-by: Mimi Zohar

selinux: fix double free of cond_list on error paths

2022-02-02T16:02:10+00:00

On error path from cond_read_list() and duplicate_policydb_cond_list()
the cond_list_destroy() gets called a second time in caller functions,
resulting in NULL pointer deref.  Fix this by resetting the
cond_list_len to 0 in cond_list_destroy(), making subsequent calls a
noop.

Also consistently reset the cond_list pointer to NULL after freeing.

Cc: stable@vger.kernel.org
Signed-off-by: Vratislav Bendel 
[PM: fix line lengths in the description]
Signed-off-by: Paul Moore

Merge tag 'fixes-v5.17-lsm-ceph-null' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

2022-01-29T06:52:27+00:00

Pull security sybsystem fix from James Morris:
 "Fix NULL pointer crash in LSM via Ceph, from Vivek Goyal"

* tag 'fixes-v5.17-lsm-ceph-null' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  security, lsm: dentry_init_security() Handle multi LSM registration

security, lsm: dentry_init_security() Handle multi LSM registration

2022-01-28T18:53:26+00:00

A ceph user has reported that ceph is crashing with kernel NULL pointer
dereference. Following is the backtrace.

/proc/version: Linux version 5.16.2-arch1-1 (linux@archlinux) (gcc (GCC)
11.1.0, GNU ld (GNU Binutils) 2.36.1) #1 SMP PREEMPT Thu, 20 Jan 2022
16:18:29 +0000
distro / arch: Arch Linux / x86_64
SELinux is not enabled
ceph cluster version: 16.2.7 (dd0603118f56ab514f133c8d2e3adfc983942503)

relevant dmesg output:
[   30.947129] BUG: kernel NULL pointer dereference, address:
0000000000000000
[   30.947206] #PF: supervisor read access in kernel mode
[   30.947258] #PF: error_code(0x0000) - not-present page
[   30.947310] PGD 0 P4D 0
[   30.947342] Oops: 0000 [#1] PREEMPT SMP PTI
[   30.947388] CPU: 5 PID: 778 Comm: touch Not tainted 5.16.2-arch1-1 #1
86fbf2c313cc37a553d65deb81d98e9dcc2a3659
[   30.947486] Hardware name: Gigabyte Technology Co., Ltd. B365M
DS3H/B365M DS3H, BIOS F5 08/13/2019
[   30.947569] RIP: 0010:strlen+0x0/0x20
[   30.947616] Code: b6 07 38 d0 74 16 48 83 c7 01 84 c0 74 05 48 39 f7 75
ec 31 c0 31 d2 89 d6 89 d7 c3 48 89 f8 31 d2 89 d6 89 d7 c3 0
f 1f 40 00 <80> 3f 00 74 12 48 89 f8 48 83 c0 01 80 38 00 75 f7 48 29 f8 31
ff
[   30.947782] RSP: 0018:ffffa4ed80ffbbb8 EFLAGS: 00010246
[   30.947836] RAX: 0000000000000000 RBX: ffffa4ed80ffbc60 RCX:
0000000000000000
[   30.947904] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
0000000000000000
[   30.947971] RBP: ffff94b0d15c0ae0 R08: 0000000000000000 R09:
0000000000000000
[   30.948040] R10: 0000000000000000 R11: 0000000000000000 R12:
0000000000000000
[   30.948106] R13: 0000000000000001 R14: ffffa4ed80ffbc60 R15:
0000000000000000
[   30.948174] FS:  00007fc7520f0740(0000) GS:ffff94b7ced40000(0000)
knlGS:0000000000000000
[   30.948252] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   30.948308] CR2: 0000000000000000 CR3: 0000000104a40001 CR4:
00000000003706e0
[   30.948376] Call Trace:
[   30.948404]  
[   30.948431]  ceph_security_init_secctx+0x7b/0x240 [ceph
49f9c4b9bf5be8760f19f1747e26da33920bce4b]
[   30.948582]  ceph_atomic_open+0x51e/0x8a0 [ceph
49f9c4b9bf5be8760f19f1747e26da33920bce4b]
[   30.948708]  ? get_cached_acl+0x4d/0xa0
[   30.948759]  path_openat+0x60d/0x1030
[   30.948809]  do_filp_open+0xa5/0x150
[   30.948859]  do_sys_openat2+0xc4/0x190
[   30.948904]  __x64_sys_openat+0x53/0xa0
[   30.948948]  do_syscall_64+0x5c/0x90
[   30.948989]  ? exc_page_fault+0x72/0x180
[   30.949034]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[   30.949091] RIP: 0033:0x7fc7521e25bb
[   30.950849] Code: 25 00 00 41 00 3d 00 00 41 00 74 4b 64 8b 04 25 18 00
00 00 85 c0 75 67 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 0
0 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 91 00 00 00 48 8b 54 24 28 64 48 2b 14
25

Core of the problem is that ceph checks for return code from
security_dentry_init_security() and if return code is 0, it assumes
everything is fine and continues to call strlen(name), which crashes.

Typically SELinux LSM returns 0 and sets name to "security.selinux" and
it is not a problem. Or if selinux is not compiled in or disabled, it
returns -EOPNOTSUP and ceph deals with it.

But somehow in this configuration, 0 is being returned and "name" is
not being initialized and that's creating the problem.

Our suspicion is that BPF LSM is registering a hook for
dentry_init_security() and returns hook default of 0.

LSM_HOOK(int, 0, dentry_init_security, struct dentry *dentry,...)

I have not been able to reproduce it just by doing CONFIG_BPF_LSM=y.
Stephen has tested the patch though and confirms it solves the problem
for him.

dentry_init_security() is written in such a way that it expects only one
LSM to register the hook. Atleast that's the expectation with current code.

If another LSM returns a hook and returns default, it will simply return
0 as of now and that will break ceph.

Hence, suggestion is that change semantics of this hook a bit. If there
are no LSMs or no LSM is taking ownership and initializing security context,
then return -EOPNOTSUP. Also allow at max one LSM to initialize security
context. This hook can't deal with multiple LSMs trying to init security
context. This patch implements this new behavior.

Reported-by: Stephen Muth 
Tested-by: Stephen Muth 
Suggested-by: Casey Schaufler 
Acked-by: Casey Schaufler 
Reviewed-by: Serge Hallyn 
Cc: Jeff Layton 
Cc: Christian Brauner 
Cc: Paul Moore 
Cc:  # 5.16.0
Signed-off-by: Vivek Goyal 
Reviewed-by: Jeff Layton 
Acked-by: Paul Moore 
Acked-by: Christian Brauner 
Signed-off-by: James Morris

ima: fix reference leak in asymmetric_verify()

2022-01-24T23:37:36+00:00

Don't leak a reference to the key if its algorithm is unknown.

Fixes: 947d70597236 ("ima: Support EC keys for signature verification")
Cc:  # v5.13+
Signed-off-by: Eric Biggers 
Reviewed-by: Stefan Berger 
Reviewed-by: Tianjia Zhang 
Signed-off-by: Mimi Zohar