[pve-devel] [PATCH kernel 1/2] cherry-pick fix for NULL pointer dereference in apparmorfs

[Fiona Ebner]

Reported in the community forum:
https://forum.proxmox.com/threads/145760/post-690328

Signed-off-by: Fiona Ebner <f.ebner at proxmox.com>
---
 ...ix-possible-NULL-pointer-dereference.patch | 101 ++++++++++++++++++
 1 file changed, 101 insertions(+)
 create mode 100644 patches/kernel/0023-apparmor-fix-possible-NULL-pointer-dereference.patch

diff --git a/patches/kernel/0023-apparmor-fix-possible-NULL-pointer-dereference.patch b/patches/kernel/0023-apparmor-fix-possible-NULL-pointer-dereference.patch
new file mode 100644
index 0000000..36d4297
--- /dev/null
+++ b/patches/kernel/0023-apparmor-fix-possible-NULL-pointer-dereference.patch
@@ -0,0 +1,101 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Leesoo Ahn <lsahn at ooseel.net>
+Date: Wed, 8 May 2024 01:12:29 +0900
+Subject: [PATCH] apparmor: fix possible NULL pointer dereference
+
+profile->parent->dents[AAFS_PROF_DIR] could be NULL only if its parent is made
+from __create_missing_ancestors(..) and 'ent->old' is NULL in
+aa_replace_profiles(..).
+In that case, it must return an error code and the code, -ENOENT represents
+its state that the path of its parent is not existed yet.
+
+BUG: kernel NULL pointer dereference, address: 0000000000000030
+PGD 0 P4D 0
+PREEMPT SMP PTI
+CPU: 4 PID: 3362 Comm: apparmor_parser Not tainted 6.8.0-24-generic #24
+Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
+RIP: 0010:aafs_create.constprop.0+0x7f/0x130
+Code: 4c 63 e0 48 83 c4 18 4c 89 e0 5b 41 5c 41 5d 41 5e 41 5f 5d 31 d2 31 c9 31 f6 31 ff 45 31 c0 45 31 c9 45 31 d2 c3 cc cc cc cc <4d> 8b 55 30 4d 8d ba a0 00 00 00 4c 89 55 c0 4c 89 ff e8 7a 6a ae
+RSP: 0018:ffffc9000b2c7c98 EFLAGS: 00010246
+RAX: 0000000000000000 RBX: 00000000000041ed RCX: 0000000000000000
+RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
+RBP: ffffc9000b2c7cd8 R08: 0000000000000000 R09: 0000000000000000
+R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff82baac10
+R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
+FS:  00007be9f22cf740(0000) GS:ffff88817bc00000(0000) knlGS:0000000000000000
+CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
+CR2: 0000000000000030 CR3: 0000000134b08000 CR4: 00000000000006f0
+Call Trace:
+ <TASK>
+ ? show_regs+0x6d/0x80
+ ? __die+0x24/0x80
+ ? page_fault_oops+0x99/0x1b0
+ ? kernelmode_fixup_or_oops+0xb2/0x140
+ ? __bad_area_nosemaphore+0x1a5/0x2c0
+ ? find_vma+0x34/0x60
+ ? bad_area_nosemaphore+0x16/0x30
+ ? do_user_addr_fault+0x2a2/0x6b0
+ ? exc_page_fault+0x83/0x1b0
+ ? asm_exc_page_fault+0x27/0x30
+ ? aafs_create.constprop.0+0x7f/0x130
+ ? aafs_create.constprop.0+0x51/0x130
+ __aafs_profile_mkdir+0x3d6/0x480
+ aa_replace_profiles+0x83f/0x1270
+ policy_update+0xe3/0x180
+ profile_load+0xbc/0x150
+ ? rw_verify_area+0x47/0x140
+ vfs_write+0x100/0x480
+ ? __x64_sys_openat+0x55/0xa0
+ ? syscall_exit_to_user_mode+0x86/0x260
+ ksys_write+0x73/0x100
+ __x64_sys_write+0x19/0x30
+ x64_sys_call+0x7e/0x25c0
+ do_syscall_64+0x7f/0x180
+ entry_SYSCALL_64_after_hwframe+0x78/0x80
+RIP: 0033:0x7be9f211c574
+Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d d5 ea 0e 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89
+RSP: 002b:00007ffd26f2b8c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
+RAX: ffffffffffffffda RBX: 00005d504415e200 RCX: 00007be9f211c574
+RDX: 0000000000001fc1 RSI: 00005d504418bc80 RDI: 0000000000000004
+RBP: 0000000000001fc1 R08: 0000000000001fc1 R09: 0000000080000000
+R10: 0000000000000000 R11: 0000000000000202 R12: 00005d504418bc80
+R13: 0000000000000004 R14: 00007ffd26f2b9b0 R15: 00007ffd26f2ba30
+ </TASK>
+Modules linked in: snd_seq_dummy snd_hrtimer qrtr snd_hda_codec_generic snd_hda_intel snd_intel_dspcfg snd_intel_sdw_acpi snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device i2c_i801 snd_timer i2c_smbus qxl snd soundcore drm_ttm_helper lpc_ich ttm joydev input_leds serio_raw mac_hid binfmt_misc msr parport_pc ppdev lp parport efi_pstore nfnetlink dmi_sysfs qemu_fw_cfg ip_tables x_tables autofs4 hid_generic usbhid hid ahci libahci psmouse virtio_rng xhci_pci xhci_pci_renesas
+CR2: 0000000000000030
+---[ end trace 0000000000000000 ]---
+RIP: 0010:aafs_create.constprop.0+0x7f/0x130
+Code: 4c 63 e0 48 83 c4 18 4c 89 e0 5b 41 5c 41 5d 41 5e 41 5f 5d 31 d2 31 c9 31 f6 31 ff 45 31 c0 45 31 c9 45 31 d2 c3 cc cc cc cc <4d> 8b 55 30 4d 8d ba a0 00 00 00 4c 89 55 c0 4c 89 ff e8 7a 6a ae
+RSP: 0018:ffffc9000b2c7c98 EFLAGS: 00010246
+RAX: 0000000000000000 RBX: 00000000000041ed RCX: 0000000000000000
+RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
+RBP: ffffc9000b2c7cd8 R08: 0000000000000000 R09: 0000000000000000
+R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff82baac10
+R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
+FS:  00007be9f22cf740(0000) GS:ffff88817bc00000(0000) knlGS:0000000000000000
+CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
+CR2: 0000000000000030 CR3: 0000000134b08000 CR4: 00000000000006f0
+
+Signed-off-by: Leesoo Ahn <lsahn at ooseel.net>
+Signed-off-by: John Johansen <john.johansen at canonical.com>
+(cherry picked from commit 3dd384108d53834002be5630132ad5c3f32166ad)
+Signed-off-by: Fiona Ebner <f.ebner at proxmox.com>
+---
+ security/apparmor/apparmorfs.c | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
+index be6c3293c9e0..822f2e6a96a7 100644
+--- a/security/apparmor/apparmorfs.c
++++ b/security/apparmor/apparmorfs.c
+@@ -1921,6 +1921,10 @@ int __aafs_profile_mkdir(struct aa_profile *profile, struct dentry *parent)
+ 		struct aa_profile *p;
+ 		p = aa_deref_parent(profile);
+ 		dent = prof_dir(p);
++		if (!dent) {
++			error = -ENOENT;
++			goto fail2;
++		}
+ 		/* adding to parent that previously didn't have children */
+ 		dent = aafs_create_dir("profiles", dent);
+ 		if (IS_ERR(dent))
-- 
2.39.2