linux-stable.git/security, branch v6.10.3

selinux,smack: remove the capability checks in the removexattr hooks

2024-08-03T07:01:09+00:00

commit dd44477e7fa15ba3b100dfc67bf7cf083f3dccf6 upstream.

Commit 61df7b828204 ("lsm: fixup the inode xattr capability handling")
moved the responsibility of doing the inode xattr capability checking
out of the individual LSMs and into the LSM framework itself.
Unfortunately, while the original commit added the capability checks
to both the setxattr and removexattr code in the LSM framework, it
only removed the setxattr capability checks from the individual LSMs,
leaving duplicated removexattr capability checks in both the SELinux
and Smack code.

This patch removes the duplicated code from SELinux and Smack.

Fixes: 61df7b828204 ("lsm: fixup the inode xattr capability handling")
Acked-by: Casey Schaufler 
Signed-off-by: Paul Moore 
Signed-off-by: Greg Kroah-Hartman

apparmor: unpack transition table if dfa is not present

2024-08-03T07:01:08+00:00

[ Upstream commit e0ff0cff1f6cdce0aa596aac04129893201c4162 ]

Due to a bug in earlier userspaces, a transition table may be present
even when the dfa is not. Commit 7572fea31e3e
("apparmor: convert fperm lookup to use accept as an index") made the
verification check more rigourous regressing old userspaces with
the bug. For compatibility reasons allow the orphaned transition table
during unpack and discard.

Fixes: 7572fea31e3e ("apparmor: convert fperm lookup to use accept as an index")
Signed-off-by: Georgia Garcia 
Signed-off-by: John Johansen 
Signed-off-by: Sasha Levin

apparmor: Fix null pointer deref when receiving skb during sock creation

2024-08-03T07:01:04+00:00

[ Upstream commit fce09ea314505a52f2436397608fa0a5d0934fb1 ]

The panic below is observed when receiving ICMP packets with secmark set
while an ICMP raw socket is being created. SK_CTX(sk)->label is updated
in apparmor_socket_post_create(), but the packet is delivered to the
socket before that, causing the null pointer dereference.
Drop the packet if label context is not set.

    BUG: kernel NULL pointer dereference, address: 000000000000004c
    #PF: supervisor read access in kernel mode
    #PF: error_code(0x0000) - not-present page
    PGD 0 P4D 0
    Oops: 0000 [#1] PREEMPT SMP NOPTI
    CPU: 0 PID: 407 Comm: a.out Not tainted 6.4.12-arch1-1 #1 3e6fa2753a2d75925c34ecb78e22e85a65d083df
    Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/28/2020
    RIP: 0010:aa_label_next_confined+0xb/0x40
    Code: 00 00 48 89 ef e8 d5 25 0c 00 e9 66 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 0f 1f 44 00 00 89 f0 <8b> 77 4c 39 c6 7e 1f 48 63 d0 48 8d 14 d7 eb 0b 83 c0 01 48 83 c2
    RSP: 0018:ffffa92940003b08 EFLAGS: 00010246
    RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000000000000e
    RDX: ffffa92940003be8 RSI: 0000000000000000 RDI: 0000000000000000
    RBP: ffff8b57471e7800 R08: ffff8b574c642400 R09: 0000000000000002
    R10: ffffffffbd820eeb R11: ffffffffbeb7ff00 R12: ffff8b574c642400
    R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000000
    FS:  00007fb092ea7640(0000) GS:ffff8b577bc00000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 000000000000004c CR3: 00000001020f2005 CR4: 00000000007706f0
    PKRU: 55555554
    Call Trace:
     
     ? __die+0x23/0x70
     ? page_fault_oops+0x171/0x4e0
     ? exc_page_fault+0x7f/0x180
     ? asm_exc_page_fault+0x26/0x30
     ? aa_label_next_confined+0xb/0x40
     apparmor_secmark_check+0xec/0x330
     security_sock_rcv_skb+0x35/0x50
     sk_filter_trim_cap+0x47/0x250
     sock_queue_rcv_skb_reason+0x20/0x60
     raw_rcv+0x13c/0x210
     raw_local_deliver+0x1f3/0x250
     ip_protocol_deliver_rcu+0x4f/0x2f0
     ip_local_deliver_finish+0x76/0xa0
     __netif_receive_skb_one_core+0x89/0xa0
     netif_receive_skb+0x119/0x170
     ? __netdev_alloc_skb+0x3d/0x140
     vmxnet3_rq_rx_complete+0xb23/0x1010 [vmxnet3 56a84f9c97178c57a43a24ec073b45a9d6f01f3a]
     vmxnet3_poll_rx_only+0x36/0xb0 [vmxnet3 56a84f9c97178c57a43a24ec073b45a9d6f01f3a]
     __napi_poll+0x28/0x1b0
     net_rx_action+0x2a4/0x380
     __do_softirq+0xd1/0x2c8
     __irq_exit_rcu+0xbb/0xf0
     common_interrupt+0x86/0xa0
     
     
     asm_common_interrupt+0x26/0x40
    RIP: 0010:apparmor_socket_post_create+0xb/0x200
    Code: 08 48 85 ff 75 a1 eb b1 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 41 54 <55> 48 89 fd 53 45 85 c0 0f 84 b2 00 00 00 48 8b 1d 80 56 3f 02 48
    RSP: 0018:ffffa92940ce7e50 EFLAGS: 00000286
    RAX: ffffffffbc756440 RBX: 0000000000000000 RCX: 0000000000000001
    RDX: 0000000000000003 RSI: 0000000000000002 RDI: ffff8b574eaab740
    RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
    R10: ffff8b57444cec70 R11: 0000000000000000 R12: 0000000000000003
    R13: 0000000000000002 R14: ffff8b574eaab740 R15: ffffffffbd8e4748
     ? __pfx_apparmor_socket_post_create+0x10/0x10
     security_socket_post_create+0x4b/0x80
     __sock_create+0x176/0x1f0
     __sys_socket+0x89/0x100
     __x64_sys_socket+0x17/0x20
     do_syscall_64+0x5d/0x90
     ? do_syscall_64+0x6c/0x90
     ? do_syscall_64+0x6c/0x90
     ? do_syscall_64+0x6c/0x90
     entry_SYSCALL_64_after_hwframe+0x72/0xdc

Fixes: ab9f2115081a ("apparmor: Allow filtering based on secmark policy")
Signed-off-by: Xiao Liang 
Signed-off-by: John Johansen 
Signed-off-by: Sasha Levin

task_work: s/task_work_cancel()/task_work_cancel_func()/

2024-08-03T07:00:36+00:00

commit 68cbd415dd4b9c5b9df69f0f091879e56bf5907a upstream.

A proper task_work_cancel() API that actually cancels a callback and not
*any* callback pointing to a given function is going to be needed for
perf events event freeing. Do the appropriate rename to prepare for
that.

Signed-off-by: Frederic Weisbecker 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240621091601.18227-2-frederic@kernel.org
Signed-off-by: Greg Kroah-Hartman

apparmor: use kvfree_sensitive to free data->data

2024-08-03T07:00:35+00:00

commit 2bc73505a5cd2a18a7a542022722f136c19e3b87 upstream.

Inside unpack_profile() data->data is allocated using kvmemdup() so it
should be freed with the corresponding kvfree_sensitive().

Also add missing data->data release for rhashtable insertion failure path
in unpack_profile().

Found by Linux Verification Center (linuxtesting.org).

Fixes: e025be0f26d5 ("apparmor: support querying extended trusted helper extra data")
Cc: stable@vger.kernel.org
Signed-off-by: Fedor Pchelkin 
Signed-off-by: John Johansen 
Signed-off-by: Greg Kroah-Hartman

lsm: fixup the inode xattr capability handling

2024-08-03T07:00:34+00:00

commit 61df7b82820494368bd46071ca97e43a3dfc3b11 upstream.

The current security_inode_setxattr() and security_inode_removexattr()
hooks rely on individual LSMs to either call into the associated
capability hooks (cap_inode_setxattr() or cap_inode_removexattr()), or
return a magic value of 1 to indicate that the LSM layer itself should
perform the capability checks.  Unfortunately, with the default return
value for these LSM hooks being 0, an individual LSM hook returning a
1 will cause the LSM hook processing to exit early, potentially
skipping a LSM.  Thankfully, with the exception of the BPF LSM, none
of the LSMs which currently register inode xattr hooks should end up
returning a value of 1, and in the BPF LSM case, with the BPF LSM hooks
executing last there should be no real harm in stopping processing of
the LSM hooks.  However, the reliance on the individual LSMs to either
call the capability hooks themselves, or signal the LSM with a return
value of 1, is fragile and relies on a specific set of LSMs being
enabled.  This patch is an effort to resolve, or minimize, these
issues.

Before we discuss the solution, there are a few observations and
considerations that we need to take into account:
* BPF LSM registers an implementation for every LSM hook, and that
  implementation simply returns the hook's default return value, a
  0 in this case.  We want to ensure that the default BPF LSM behavior
  results in the capability checks being called.
* SELinux and Smack do not expect the traditional capability checks
  to be applied to the xattrs that they "own".
* SELinux and Smack are currently written in such a way that the
  xattr capability checks happen before any additional LSM specific
  access control checks.  SELinux does apply SELinux specific access
  controls to all xattrs, even those not "owned" by SELinux.
* IMA and EVM also register xattr hooks but assume that the LSM layer
  and specific LSMs have already authorized the basic xattr operation.

In order to ensure we perform the capability based access controls
before the individual LSM access controls, perform only one capability
access control check for each operation, and clarify the logic around
applying the capability controls, we need a mechanism to determine if
any of the enabled LSMs "own" a particular xattr and want to take
responsibility for controlling access to that xattr.  The solution in
this patch is to create a new LSM hook, 'inode_xattr_skipcap', that is
not exported to the rest of the kernel via a security_XXX() function,
but is used by the LSM layer to determine if a LSM wants to control
access to a given xattr and avoid the traditional capability controls.
Registering an inode_xattr_skipcap hook is optional, if a LSM declines
to register an implementation, or uses an implementation that simply
returns the default value (0), there is no effect as the LSM continues
to enforce the capability based controls (unless another LSM takes
ownership of the xattr).  If none of the LSMs signal that the
capability checks should be skipped, the capability check is performed
and if access is granted the individual LSM xattr access control hooks
are executed, keeping with the DAC-before-LSM convention.

Cc: stable@vger.kernel.org
Acked-by: Casey Schaufler 
Signed-off-by: Paul Moore 
Signed-off-by: Greg Kroah-Hartman

landlock: Don't lose track of restrictions on cred_transfer

2024-08-03T07:00:28+00:00

commit 39705a6c29f8a2b93cf5b99528a55366c50014d1 upstream.

When a process' cred struct is replaced, this _almost_ always invokes
the cred_prepare LSM hook; but in one special case (when
KEYCTL_SESSION_TO_PARENT updates the parent's credentials), the
cred_transfer LSM hook is used instead.  Landlock only implements the
cred_prepare hook, not cred_transfer, so KEYCTL_SESSION_TO_PARENT causes
all information on Landlock restrictions to be lost.

This basically means that a process with the ability to use the fork()
and keyctl() syscalls can get rid of all Landlock restrictions on
itself.

Fix it by adding a cred_transfer hook that does the same thing as the
existing cred_prepare hook. (Implemented by having hook_cred_prepare()
call hook_cred_transfer() so that the two functions are less likely to
accidentally diverge in the future.)

Cc: stable@kernel.org
Fixes: 385975dca53e ("landlock: Set up the security framework and manage credentials")
Signed-off-by: Jann Horn 
Link: https://lore.kernel.org/r/20240724-landlock-houdini-fix-v1-1-df89a4560ca3@google.com
Signed-off-by: Mickaël Salaün 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'integrity-v6.10-fix' of ssh://ra.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

2024-07-05T23:21:54+00:00

Pull integrity fix from Mimi Zohar:
 "A single bug fix to properly remove all of the securityfs IMA
  measurement lists"

* tag 'integrity-v6.10-fix' of ssh://ra.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  ima: fix wrong zero-assignment during securityfs dentry remove

Merge tag 'lsm-pr-20240617' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm

2024-06-18T01:35:12+00:00

Pull lsm fix from Paul Moore:
 "A single LSM/IMA patch to fix a problem caused by sleeping while in a
  RCU critical section"

* tag 'lsm-pr-20240617' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm:
  ima: Avoid blocking in RCU read-side critical section

Merge tag 'mm-hotfixes-stable-2024-06-17-11-43' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-06-17T19:30:07+00:00

Pull misc fixes from Andrew Morton:
 "Mainly MM singleton fixes. And a couple of ocfs2 regression fixes"

* tag 'mm-hotfixes-stable-2024-06-17-11-43' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  kcov: don't lose track of remote references during softirqs
  mm: shmem: fix getting incorrect lruvec when replacing a shmem folio
  mm/debug_vm_pgtable: drop RANDOM_ORVALUE trick
  mm: fix possible OOB in numa_rebuild_large_mapping()
  mm/migrate: fix kernel BUG at mm/compaction.c:2761!
  selftests: mm: make map_fixed_noreplace test names stable
  mm/memfd: add documentation for MFD_NOEXEC_SEAL MFD_EXEC
  mm: mmap: allow for the maximum number of bits for randomizing mmap_base by default
  gcov: add support for GCC 14
  zap_pid_ns_processes: clear TIF_NOTIFY_SIGNAL along with TIF_SIGPENDING
  mm: huge_memory: fix misused mapping_large_folio_support() for anon folios
  lib/alloc_tag: fix RCU imbalance in pgalloc_tag_get()
  lib/alloc_tag: do not register sysctl interface when CONFIG_SYSCTL=n
  MAINTAINERS: remove Lorenzo as vmalloc reviewer
  Revert "mm: init_mlocked_on_free_v3"
  mm/page_table_check: fix crash on ZONE_DEVICE
  gcc: disable '-Warray-bounds' for gcc-9
  ocfs2: fix NULL pointer dereference in ocfs2_abort_trigger()
  ocfs2: fix NULL pointer dereference in ocfs2_journal_dirty()