linux.git/security, branch v6.6.18

lsm: fix the logic in security_inode_getsecctx()

2024-02-23T08:25:02+00:00

commit 99b817c173cd213671daecd25ca27f56b0c7c4ec upstream.

The inode_getsecctx LSM hook has previously been corrected to have
-EOPNOTSUPP instead of 0 as the default return value to fix BPF LSM
behavior. However, the call_int_hook()-generated loop in
security_inode_getsecctx() was left treating 0 as the neutral value, so
after an LSM returns 0, the loop continues to try other LSMs, and if one
of them returns a non-zero value, the function immediately returns with
said value. So in a situation where SELinux and the BPF LSMs registered
this hook, -EOPNOTSUPP would be incorrectly returned whenever SELinux
returned 0.

Fix this by open-coding the call_int_hook() loop and making it use the
correct LSM_RET_DEFAULT() value as the neutral one, similar to what
other hooks do.

Cc: stable@vger.kernel.org
Reported-by: Stephen Smalley 
Link: https://lore.kernel.org/selinux/CAEjxPJ4ev-pasUwGx48fDhnmjBnq_Wh90jYPwRQRAqXxmOKD4Q@mail.gmail.com/
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2257983
Fixes: b36995b8609a ("lsm: fix default return value for inode_getsecctx")
Signed-off-by: Ondrej Mosnacek 
Reviewed-by: Casey Schaufler 
[PM: subject line tweak]
Signed-off-by: Paul Moore 
Signed-off-by: Greg Kroah-Hartman

lsm: fix default return value of the socket_getpeersec_*() hooks

2024-02-23T08:25:02+00:00

commit 5a287d3d2b9de2b3e747132c615599907ba5c3c1 upstream.

For these hooks the true "neutral" value is -EOPNOTSUPP, which is
currently what is returned when no LSM provides this hook and what LSMs
return when there is no security context set on the socket. Correct the
value in  and adjust the dispatch functions in
security/security.c to avoid issues when the BPF LSM is enabled.

Cc: stable@vger.kernel.org
Fixes: 98e828a0650f ("security: Refactor declaration of LSM hooks")
Signed-off-by: Ondrej Mosnacek 
[PM: subject line tweak]
Signed-off-by: Paul Moore 
Signed-off-by: Greg Kroah-Hartman

lsm: new security_file_ioctl_compat() hook

2024-02-01T00:18:54+00:00

commit f1bb47a31dff6d4b34fb14e99850860ee74bb003 upstream.

Some ioctl commands do not require ioctl permission, but are routed to
other permissions such as FILE_GETATTR or FILE_SETATTR. This routing is
done by comparing the ioctl cmd to a set of 64-bit flags (FS_IOC_*).

However, if a 32-bit process is running on a 64-bit kernel, it emits
32-bit flags (FS_IOC32_*) for certain ioctl operations. These flags are
being checked erroneously, which leads to these ioctl operations being
routed to the ioctl permission, rather than the correct file
permissions.

This was also noted in a RED-PEN finding from a while back -
"/* RED-PEN how should LSM module know it's handling 32bit? */".

This patch introduces a new hook, security_file_ioctl_compat(), that is
called from the compat ioctl syscall. All current LSMs have been changed
to support this hook.

Reviewing the three places where we are currently using
security_file_ioctl(), it appears that only SELinux needs a dedicated
compat change; TOMOYO and SMACK appear to be functional without any
change.

Cc: stable@vger.kernel.org
Fixes: 0b24dcb7f2f7 ("Revert "selinux: simplify ioctl checking"")
Signed-off-by: Alfred Piccioni 
Reviewed-by: Stephen Smalley 
[PM: subject tweak, line length fixes, and alignment corrections]
Signed-off-by: Paul Moore 
Signed-off-by: Greg Kroah-Hartman

Revert "KEYS: encrypted: Add check for strsep"

2024-01-25T23:36:01+00:00

commit 1ed4b563100230ea68821a2b25a3d9f25388a3e6 upstream.

This reverts commit b4af096b5df5dd131ab796c79cedc7069d8f4882.

New encrypted keys are created either from kernel-generated random
numbers or user-provided decrypted data.  Revert the change requiring
user-provided decrypted data.

Reported-by: Vishal Verma 
Signed-off-by: Mimi Zohar 
Signed-off-by: Greg Kroah-Hartman

apparmor: avoid crash when parsed profile name is empty

2024-01-25T23:35:54+00:00

[ Upstream commit 55a8210c9e7d21ff2644809699765796d4bfb200 ]

When processing a packed profile in unpack_profile() described like

 "profile :ns::samba-dcerpcd /usr/lib*/samba/{,samba/}samba-dcerpcd {...}"

a string ":samba-dcerpcd" is unpacked as a fully-qualified name and then
passed to aa_splitn_fqname().

aa_splitn_fqname() treats ":samba-dcerpcd" as only containing a namespace.
Thus it returns NULL for tmpname, meanwhile tmpns is non-NULL. Later
aa_alloc_profile() crashes as the new profile name is NULL now.

general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 6 PID: 1657 Comm: apparmor_parser Not tainted 6.7.0-rc2-dirty #16
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
RIP: 0010:strlen+0x1e/0xa0
Call Trace:
 
 ? strlen+0x1e/0xa0
 aa_policy_init+0x1bb/0x230
 aa_alloc_profile+0xb1/0x480
 unpack_profile+0x3bc/0x4960
 aa_unpack+0x309/0x15e0
 aa_replace_profiles+0x213/0x33c0
 policy_update+0x261/0x370
 profile_replace+0x20e/0x2a0
 vfs_write+0x2af/0xe00
 ksys_write+0x126/0x250
 do_syscall_64+0x46/0xf0
 entry_SYSCALL_64_after_hwframe+0x6e/0x76
 
---[ end trace 0000000000000000 ]---
RIP: 0010:strlen+0x1e/0xa0

It seems such behaviour of aa_splitn_fqname() is expected and checked in
other places where it is called (e.g. aa_remove_profiles). Well, there
is an explicit comment "a ns name without a following profile is allowed"
inside.

AFAICS, nothing can prevent unpacked "name" to be in form like
":samba-dcerpcd" - it is passed from userspace.

Deny the whole profile set replacement in such case and inform user with
EPROTO and an explaining message.

Found by Linux Verification Center (linuxtesting.org).

Fixes: 04dc715e24d0 ("apparmor: audit policy ns specified in policy load")
Signed-off-by: Fedor Pchelkin 
Signed-off-by: John Johansen 
Signed-off-by: Sasha Levin

apparmor: fix possible memory leak in unpack_trans_table

2024-01-25T23:35:54+00:00

[ Upstream commit 1342ad786073e96fa813ad943c19f586157ae297 ]

If we fail to unpack the transition table then the table elements which
have been already allocated are not freed on error path.

unreferenced object 0xffff88802539e000 (size 128):
  comm "apparmor_parser", pid 903, jiffies 4294914938 (age 35.085s)
  hex dump (first 32 bytes):
    20 73 6f 6d 65 20 6e 61 73 74 79 20 73 74 72 69   some nasty stri
    6e 67 20 73 6f 6d 65 20 6e 61 73 74 79 20 73 74  ng some nasty st
  backtrace:
    [] __kmem_cache_alloc_node+0x1e2/0x2d0
    [] __kmalloc_node_track_caller+0x54/0x170
    [] kmemdup+0x29/0x60
    [] aa_unpack_strdup+0xe5/0x1b0
    [] unpack_pdb+0xeb8/0x2700
    [] unpack_profile+0x1507/0x4a30
    [] aa_unpack+0x36a/0x1560
    [] aa_replace_profiles+0x213/0x33c0
    [] policy_update+0x261/0x370
    [] profile_replace+0x20e/0x2a0
    [] vfs_write+0x2af/0xe00
    [] ksys_write+0x126/0x250
    [] do_syscall_64+0x46/0xf0
    [] entry_SYSCALL_64_after_hwframe+0x6e/0x76

Call aa_free_str_table() on error path as was done before the blamed
commit. It implements all necessary checks, frees str_table if it is
available and nullifies the pointers.

Found by Linux Verification Center (linuxtesting.org).

Fixes: a0792e2ceddc ("apparmor: make transition table unpack generic so it can be reused")
Signed-off-by: Fedor Pchelkin 
Signed-off-by: John Johansen 
Signed-off-by: Sasha Levin

apparmor: Fix ref count leak in task_kill

2024-01-25T23:35:54+00:00

[ Upstream commit 2cb54a19ac7153b9a26a72098c495187f64c2276 ]

apparmor_task_kill was not putting the task_cred reference tc, or the
cred_label reference tc when dealing with a passed in cred, fix this
by using a single fn exit.

Fixes: 90c436a64a6e ("apparmor: pass cred through to audit info.")
Signed-off-by: John Johansen 
Signed-off-by: Sasha Levin

selinux: Fix error priority for bind with AF_UNSPEC on PF_INET6 socket

2024-01-25T23:35:15+00:00

[ Upstream commit bbf5a1d0e5d0fb3bdf90205aa872636122692a50 ]

The IPv6 network stack first checks the sockaddr length (-EINVAL error)
before checking the family (-EAFNOSUPPORT error).

This was discovered thanks to commit a549d055a22e ("selftests/landlock:
Add network tests").

Cc: Eric Paris 
Cc: Konstantin Meskhidze 
Cc: Paul Moore 
Cc: Stephen Smalley 
Reported-by: Muhammad Usama Anjum 
Closes: https://lore.kernel.org/r/0584f91c-537c-4188-9e4f-04f192565667@collabora.com
Fixes: 0f8db8cc73df ("selinux: add AF_UNSPEC and INADDR_ANY checks to selinux_socket_bind()")
Signed-off-by: Mickaël Salaün 
Tested-by: Muhammad Usama Anjum 
Signed-off-by: Paul Moore 
Signed-off-by: Sasha Levin

KEYS: encrypted: Add check for strsep

2024-01-25T23:35:14+00:00

[ Upstream commit b4af096b5df5dd131ab796c79cedc7069d8f4882 ]

Add check for strsep() in order to transfer the error.

Fixes: cd3bc044af48 ("KEYS: encrypted: Instantiate key with user-provided decrypted data")
Signed-off-by: Chen Ni 
Signed-off-by: Mimi Zohar 
Signed-off-by: Sasha Levin

apparmor: Fix move_mount mediation by detecting if source is detached

2024-01-10T16:16:52+00:00

[ Upstream commit 8026e40608b4d552216d2a818ca7080a4264bb44 ]

Prevent move_mount from applying the attach_disconnected flag
to move_mount(). This prevents detached mounts from appearing
as / when applying mount mediation, which is not only incorrect
but could result in bad policy being generated.

Basic mount rules like
  allow mount,
  allow mount options=(move) -> /target/,

will allow detached mounts, allowing older policy to continue
to function. New policy gains the ability to specify `detached` as
a source option
  allow mount detached -> /target/,

In addition make sure support of move_mount is advertised as
a feature to userspace so that applications that generate policy
can respond to the addition.

Note: this fixes mediation of move_mount when a detached mount is used,
      it does not fix the broader regression of apparmor mediation of
      mounts under the new mount api.

Link: https://lore.kernel.org/all/68c166b8-5b4d-4612-8042-1dee3334385b@leemhuis.info/T/#mb35fdde37f999f08f0b02d58dc1bf4e6b65b8da2
Fixes: 157a3537d6bc ("apparmor: Fix regression in mount mediation")
Reviewed-by: Georgia Garcia 
Signed-off-by: John Johansen 
Signed-off-by: Sasha Levin