kernel/linux.git/security/apparmor/audit.c, branch v6.12.80

ima: Avoid blocking in RCU read-side critical section

2024-06-13T18:26:50+00:00

A panic happens in ima_match_policy: BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 PGD 42f873067 P4D 0 Oops: 0000 [#1] SMP NOPTI CPU: 5 PID: 1286325 Comm: kubeletmonit.sh Kdump: loaded Tainted: P Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 RIP: 0010:ima_match_policy+0x84/0x450 Code: 49 89 fc 41 89 cf 31 ed 89 44 24 14 eb 1c 44 39 7b 18 74 26 41 83 ff 05 74 20 48 8b 1b 48 3b 1d f2 b9 f4 00 0f 84 9c 01 00 00 <44> 85 73 10 74 ea 44 8b 6b 14 41 f6 c5 01 75 d4 41 f6 c5 02 74 0f RSP: 0018:ff71570009e07a80 EFLAGS: 00010207 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000200 RDX: ffffffffad8dc7c0 RSI: 0000000024924925 RDI: ff3e27850dea2000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffffabfce739 R10: ff3e27810cc42400 R11: 0000000000000000 R12: ff3e2781825ef970 R13: 00000000ff3e2785 R14: 000000000000000c R15: 0000000000000001 FS: 00007f5195b51740(0000) GS:ff3e278b12d40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 0000000626d24002 CR4: 0000000000361ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ima_get_action+0x22/0x30 process_measurement+0xb0/0x830 ? page_add_file_rmap+0x15/0x170 ? alloc_set_pte+0x269/0x4c0 ? prep_new_page+0x81/0x140 ? simple_xattr_get+0x75/0xa0 ? selinux_file_open+0x9d/0xf0 ima_file_check+0x64/0x90 path_openat+0x571/0x1720 do_filp_open+0x9b/0x110 ? page_counter_try_charge+0x57/0xc0 ? files_cgroup_alloc_fd+0x38/0x60 ? __alloc_fd+0xd4/0x250 ? do_sys_open+0x1bd/0x250 do_sys_open+0x1bd/0x250 do_syscall_64+0x5d/0x1d0 entry_SYSCALL_64_after_hwframe+0x65/0xca Commit c7423dbdbc9e ("ima: Handle -ESTALE returned by ima_filter_rule_match()") introduced call to ima_lsm_copy_rule within a RCU read-side critical section which contains kmalloc with GFP_KERNEL. This implies a possible sleep and violates limitations of RCU read-side critical sections on non-PREEMPT systems. Sleeping within RCU read-side critical section might cause synchronize_rcu() returning early and break RCU protection, allowing a UAF to happen. The root cause of this issue could be described as follows: | Thread A | Thread B | | |ima_match_policy | | | rcu_read_lock | |ima_lsm_update_rule | | | synchronize_rcu | | | | kmalloc(GFP_KERNEL)| | | sleep | ==> synchronize_rcu returns early | kfree(entry) | | | | entry = entry->next| ==> UAF happens and entry now becomes NULL (or could be anything). | | entry->action | ==> Accessing entry might cause panic. To fix this issue, we are converting all kmalloc that is called within RCU read-side critical section to use GFP_ATOMIC. Fixes: c7423dbdbc9e ("ima: Handle -ESTALE returned by ima_filter_rule_match()") Cc: stable@vger.kernel.org Signed-off-by: GUO Zihua Acked-by: John Johansen Reviewed-by: Mimi Zohar Reviewed-by: Casey Schaufler [PM: fixed missing comment, long lines, !CONFIG_IMA_LSM_RULES case] Signed-off-by: Paul Moore

apparmor: add io_uring mediation

2023-10-18T22:58:49+00:00

For now, the io_uring mediation is limited to sqpoll and override_creds. Signed-off-by: Georgia Garcia Signed-off-by: John Johansen

apparmor: add user namespace creation mediation

2023-10-18T22:49:02+00:00

Unprivileged user namespace creation is often used as a first step in privilege escalation attacks. Instead of disabling it at the sysrq level, which blocks its legitimate use as for setting up a sandbox, allow control on a per domain basis. This allows an admin to quickly lock down a system while also still allowing legitimate use. Reviewed-by: Georgia Garcia Signed-off-by: John Johansen

apparmor: rename audit_data->label to audit_data->subj_label

2023-10-18T22:30:34+00:00

rename audit_data's label field to subj_label to better reflect its use. Also at the same time drop unneeded assignments to ->subj_label as the later call to aa_check_perms will do the assignment if needed. Reviewed-by: Georgia Garcia Signed-off-by: John Johansen

apparmor: combine common_audit_data and apparmor_audit_data

2023-10-18T22:30:29+00:00

Everywhere where common_audit_data is used apparmor audit_data is also used. We can simplify the code and drop the use of the aad macro everywhere by combining the two structures. Reviewed-by: Georgia Garcia Signed-off-by: John Johansen

apparmor: Fix kernel-doc warnings in apparmor/audit.c

2023-07-10T08:05:25+00:00

Fix kernel-doc warnings: security/apparmor/audit.c:150: warning: Function parameter or member 'type' not described in 'aa_audit_msg' Signed-off-by: Gaosheng Cui Signed-off-by: John Johansen

AppArmor: Fix kernel-doc

2022-10-25T07:15:18+00:00

security/apparmor/audit.c:93: warning: expecting prototype for audit_base(). Prototype was for audit_pre() instead. Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=2339 Reported-by: Abaci Robot Signed-off-by: Jiapeng Chong Signed-off-by: John Johansen

apparmor: fix aa_class_names[] to match reserved classes

2022-10-03T21:49:04+00:00

The class name map did not have the reserved names added. Fix this Signed-off-by: John Johansen

apparmor: add mediation class information to auditing

2022-10-03T21:49:03+00:00

Audit messages currently don't contain the mediation class which can make them less clear than they should be in some circumstances. With newer mediation classes coming this potential confusion will become worse. Fix this by adding the mediatin class to the messages. Signed-off-by: John Johansen

apparmor: fix quiet_denied for file rules

2022-07-09T22:13:59+00:00

Global quieting of denied AppArmor generated file events is not handled correctly. Unfortunately the is checking if quieting of all audit events is set instead of just denied events. Fixes: 67012e8209df ("AppArmor: basic auditing infrastructure.") Signed-off-by: John Johansen