kernel/linux.git/security/apparmor/include/audit.h, branch v6.1.168

ima: Avoid blocking in RCU read-side critical section

2024-07-11T10:47:16+00:00

commit 9a95c5bfbf02a0a7f5983280fe284a0ff0836c34 upstream. 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 Signed-off-by: Roberto Sassu Signed-off-by: Greg Kroah-Hartman

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441

2019-06-05T15:37:17+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation version 2 of the license extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 315 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Armijn Hemel Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de Signed-off-by: Greg Kroah-Hartman

audit: remove unused actx param from audit_rule_match

2019-02-01T04:00:15+00:00

The audit_rule_match() struct audit_context *actx parameter is not used by any in-tree consumers (selinux, apparmour, integrity, smack). The audit context is an internal audit structure that should only be accessed by audit accessor functions. It was part of commit 03d37d25e0f9 ("LSM/Audit: Introduce generic Audit LSM hooks") but appears to have never been used. Remove it. Please see the github issue https://github.com/linux-audit/audit-kernel/issues/107 Signed-off-by: Richard Guy Briggs [PM: fixed the referenced commit title] Signed-off-by: Paul Moore

apparmor: Add support for audit rule filtering

2018-06-07T08:50:47+00:00

This patch adds support to Apparmor for integrating with audit rule filtering. Right now it only handles SUBJ_ROLE, interpreting it as a single component of a label. This is sufficient to get Apparmor working with IMA's appraisal rules without any modifications on the IMA side. Signed-off-by: Matthew Garrett Signed-off-by: John Johansen

apparmor: add base infastructure for socket mediation

2018-03-14T00:25:48+00:00

apparmor: audit unknown signal numbers

2018-02-09T19:30:01+00:00

Allow apparmor to audit the number of a signal that it does not provide a mapping for and is currently being reported only as unknown. Signed-off-by: John Johansen

apparmor: fix resource audit messages when auditing peer

2018-02-09T19:30:00+00:00

Resource auditing is using the peer field which is not available when the rlim data struct is used, because it is a different element of the same union. Accessing peer during resource auditing could cause garbage log entries or even oops the kernel. Move the rlim data block into the same struct as the peer field so they can be used together. CC: Fixes: 86b92cb782b3 ("apparmor: move resource checks to using labels") Signed-off-by: John Johansen

apparmor: fix oops in audit_signal_cb hook

2017-11-27T22:38:15+00:00

The apparmor_audit_data struct ordering got messed up during a merge conflict, resulting in the signal integer and peer pointer being in a union instead of a struct. For most of the 4.13 and 4.14 life cycle, this was hidden by commit 651e28c5537a ("apparmor: add base infastructure for socket mediation") which fixed the apparmor_audit_data struct when its data was added. When that commit was reverted in -rc7 the signal audit bug was exposed, and unfortunately it never showed up in any of the testing until after 4.14 was released. Shaun Khan, Zephaniah E. Loss-Cutler-Hull filed nearly simultaneous bug reports (with different oopes, the smaller of which is included below). Full credit goes to Tetsuo Handa for jumping on this as well and noticing the audit data struct problem and reporting it. [ 76.178568] BUG: unable to handle kernel paging request at ffffffff0eee3bc0 [ 76.178579] IP: audit_signal_cb+0x6c/0xe0 [ 76.178581] PGD 1a640a067 P4D 1a640a067 PUD 0 [ 76.178586] Oops: 0000 [#1] PREEMPT SMP [ 76.178589] Modules linked in: fuse rfcomm bnep usblp uvcvideo btusb btrtl btbcm btintel bluetooth ecdh_generic ip6table_filter ip6_tables xt_tcpudp nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack iptable_filter ip_tables x_tables intel_rapl joydev wmi_bmof serio_raw iwldvm iwlwifi shpchp kvm_intel kvm irqbypass autofs4 algif_skcipher nls_iso8859_1 nls_cp437 crc32_pclmul ghash_clmulni_intel [ 76.178620] CPU: 0 PID: 10675 Comm: pidgin Not tainted 4.14.0-f1-dirty #135 [ 76.178623] Hardware name: Hewlett-Packard HP EliteBook Folio 9470m/18DF, BIOS 68IBD Ver. F.62 10/22/2015 [ 76.178625] task: ffff9c7a94c31dc0 task.stack: ffffa09b02a4c000 [ 76.178628] RIP: 0010:audit_signal_cb+0x6c/0xe0 [ 76.178631] RSP: 0018:ffffa09b02a4fc08 EFLAGS: 00010292 [ 76.178634] RAX: ffffa09b02a4fd60 RBX: ffff9c7aee0741f8 RCX: 0000000000000000 [ 76.178636] RDX: ffffffffee012290 RSI: 0000000000000006 RDI: ffff9c7a9493d800 [ 76.178638] RBP: ffffa09b02a4fd40 R08: 000000000000004d R09: ffffa09b02a4fc46 [ 76.178641] R10: ffffa09b02a4fcb8 R11: ffff9c7ab44f5072 R12: ffffa09b02a4fd40 [ 76.178643] R13: ffffffff9e447be0 R14: ffff9c7a94c31dc0 R15: 0000000000000001 [ 76.178646] FS: 00007f8b11ba2a80(0000) GS:ffff9c7afea00000(0000) knlGS:0000000000000000 [ 76.178648] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 76.178650] CR2: ffffffff0eee3bc0 CR3: 00000003d5209002 CR4: 00000000001606f0 [ 76.178652] Call Trace: [ 76.178660] common_lsm_audit+0x1da/0x780 [ 76.178665] ? d_absolute_path+0x60/0x90 [ 76.178669] ? aa_check_perms+0xcd/0xe0 [ 76.178672] aa_check_perms+0xcd/0xe0 [ 76.178675] profile_signal_perm.part.0+0x90/0xa0 [ 76.178679] aa_may_signal+0x16e/0x1b0 [ 76.178686] apparmor_task_kill+0x51/0x120 [ 76.178690] security_task_kill+0x44/0x60 [ 76.178695] group_send_sig_info+0x25/0x60 [ 76.178699] kill_pid_info+0x36/0x60 [ 76.178703] SYSC_kill+0xdb/0x180 [ 76.178707] ? preempt_count_sub+0x92/0xd0 [ 76.178712] ? _raw_write_unlock_irq+0x13/0x30 [ 76.178716] ? task_work_run+0x6a/0x90 [ 76.178720] ? exit_to_usermode_loop+0x80/0xa0 [ 76.178723] entry_SYSCALL_64_fastpath+0x13/0x94 [ 76.178727] RIP: 0033:0x7f8b0e58b767 [ 76.178729] RSP: 002b:00007fff19efd4d8 EFLAGS: 00000206 ORIG_RAX: 000000000000003e [ 76.178732] RAX: ffffffffffffffda RBX: 0000557f3e3c2050 RCX: 00007f8b0e58b767 [ 76.178735] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000000263b [ 76.178737] RBP: 0000000000000000 R08: 0000557f3e3c2270 R09: 0000000000000001 [ 76.178739] R10: 000000000000022d R11: 0000000000000206 R12: 0000000000000000 [ 76.178741] R13: 0000000000000001 R14: 0000557f3e3c13c0 R15: 0000000000000000 [ 76.178745] Code: 48 8b 55 18 48 89 df 41 b8 20 00 08 01 5b 5d 48 8b 42 10 48 8b 52 30 48 63 48 4c 48 8b 44 c8 48 31 c9 48 8b 70 38 e9 f4 fd 00 00 <48> 8b 14 d5 40 27 e5 9e 48 c7 c6 7d 07 19 9f 48 89 df e8 fd 35 [ 76.178794] RIP: audit_signal_cb+0x6c/0xe0 RSP: ffffa09b02a4fc08 [ 76.178796] CR2: ffffffff0eee3bc0 [ 76.178799] ---[ end trace 514af9529297f1a3 ]--- Fixes: cd1dbf76b23d ("apparmor: add the ability to mediate signals") Reported-by: Zephaniah E. Loss-Cutler-Hull Reported-by: Shuah Khan Suggested-by: Tetsuo Handa Tested-by: Ivan Kozik Tested-by: Zephaniah E. Loss-Cutler-Hull Tested-by: Christian Boltz Tested-by: Shuah Khan Cc: stable@vger.kernel.org Signed-off-by: John Johansen

Revert "apparmor: add base infastructure for socket mediation"

2017-10-26T17:35:35+00:00

This reverts commit 651e28c5537abb39076d3949fb7618536f1d242e. This caused a regression: "The specific problem is that dnsmasq refuses to start on openSUSE Leap 42.2. The specific cause is that and attempt to open a PF_LOCAL socket gets EACCES. This means that networking doesn't function on a system with a 4.14-rc2 system." Sadly, the developers involved seemed to be in denial for several weeks about this, delaying the revert. This has not been a good release for the security subsystem, and this area needs to change development practices. Reported-and-bisected-by: James Bottomley Tracked-by: Thorsten Leemhuis Cc: John Johansen Cc: Vlastimil Babka Cc: Seth Arnold Signed-off-by: Linus Torvalds

apparmor: add base infastructure for socket mediation

2017-09-22T20:00:58+00:00