kernel/linux.git/security/apparmor/apparmorfs.c, branch v6.1.174

apparmor: fix race between freeing data and fs accessing it

2026-04-18T08:35:57+00:00

commit 8e135b8aee5a06c52a4347a5a6d51223c6f36ba3 upstream. Backport for conflicts introdued by conversion from sha1 to sha256 introduced in e44a4dc4b36c ("apparmor: switch SECURITY_APPARMOR_HASH from sha1 to sha256") AppArmor was putting the reference to i_private data on its end after removing the original entry from the file system. However the inode can and does live beyond that point and it is possible that some of the fs call back functions will be invoked after the reference has been put, which results in a race between freeing the data and accessing it through the fs. While the rawdata/loaddata is the most likely candidate to fail the race, as it has the fewest references. If properly crafted it might be possible to trigger a race for the other types stored in i_private. Fix this by moving the put of i_private referenced data to the correct place which is during inode eviction. Fixes: c961ee5f21b20 ("apparmor: convert from securityfs to apparmorfs for policy ns files") Reported-by: Qualys Security Advisory Reviewed-by: Georgia Garcia Reviewed-by: Maxime Bélair Reviewed-by: Cengiz Can Signed-off-by: John Johansen Signed-off-by: Greg Kroah-Hartman

apparmor: fix race on rawdata dereference

2026-04-18T08:35:56+00:00

commit a0b7091c4de45a7325c8780e6934a894f92ac86b upstream. There is a race condition that leads to a use-after-free situation: because the rawdata inodes are not refcounted, an attacker can start open()ing one of the rawdata files, and at the same time remove the last reference to this rawdata (by removing the corresponding profile, for example), which frees its struct aa_loaddata; as a result, when seq_rawdata_open() is reached, i_private is a dangling pointer and freed memory is accessed. The rawdata inodes weren't refcounted to avoid a circular refcount and were supposed to be held by the profile rawdata reference. However during profile removal there is a window where the vfs and profile destruction race, resulting in the use after free. Fix this by moving to a double refcount scheme. Where the profile refcount on rawdata is used to break the circular dependency. Allowing for freeing of the rawdata once all inode references to the rawdata are put. Fixes: 5d5182cae401 ("apparmor: move to per loaddata files, instead of replicating in profiles") Reported-by: Qualys Security Advisory Reviewed-by: Georgia Garcia Reviewed-by: Maxime Bélair Reviewed-by: Cengiz Can Tested-by: Salvatore Bonaccorso Signed-off-by: John Johansen Signed-off-by: Greg Kroah-Hartman

apparmor: fix unprivileged local user can do privileged policy management

2026-04-18T08:35:56+00:00

commit 6601e13e82841879406bf9f369032656f441a425 upstream. Backport for api changes introduced in 90c436a64a6e ("apparmor: pass cred through to audit info.") An unprivileged local user can load, replace, and remove profiles by opening the apparmorfs interfaces, via a confused deputy attack, by passing the opened fd to a privileged process, and getting the privileged process to write to the interface. This does require a privileged target that can be manipulated to do the write for the unprivileged process, but once such access is achieved full policy management is possible and all the possible implications that implies: removing confinement, DoS of system or target applications by denying all execution, by-passing the unprivileged user namespace restriction, to exploiting kernel bugs for a local privilege escalation. The policy management interface can not have its permissions simply changed from 0666 to 0600 because non-root processes need to be able to load policy to different policy namespaces. Instead ensure the task writing the interface has privileges that are a subset of the task that opened the interface. This is already done via policy for confined processes, but unconfined can delegate access to the opened fd, by-passing the usual policy check. Fixes: b7fd2c0340eac ("apparmor: add per policy ns .load, .replace, .remove interface files") Reported-by: Qualys Security Advisory Tested-by: Salvatore Bonaccorso Reviewed-by: Georgia Garcia Reviewed-by: Cengiz Can Signed-off-by: John Johansen Signed-off-by: Greg Kroah-Hartman

apparmor: fix invalid deref of rawdata when export_binary is unset

2026-03-04T12:20:09+00:00

[ Upstream commit df9ac55abd18628bd8cff687ea043660532a3654 ] If the export_binary parameter is disabled on runtime, profiles that were loaded before that will still have their rawdata stored in apparmorfs, with a symbolic link to the rawdata on the policy directory. When one of those profiles are replaced, the rawdata is set to NULL, but when trying to resolve the symbolic links to rawdata for that profile, it will try to dereference profile->rawdata->name when profile->rawdata is now NULL causing an oops. Fix it by checking if rawdata is set. [ 168.653080] BUG: kernel NULL pointer dereference, address: 0000000000000088 [ 168.657420] #PF: supervisor read access in kernel mode [ 168.660619] #PF: error_code(0x0000) - not-present page [ 168.663613] PGD 0 P4D 0 [ 168.665450] Oops: Oops: 0000 [#1] SMP NOPTI [ 168.667836] CPU: 1 UID: 0 PID: 1729 Comm: ls Not tainted 6.19.0-rc7+ #3 PREEMPT(voluntary) [ 168.672308] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 168.679327] RIP: 0010:rawdata_get_link_base.isra.0+0x23/0x330 [ 168.682768] Code: 90 90 90 90 90 90 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 ec 18 48 89 55 d0 48 85 ff 0f 84 e3 01 00 00 <48> 83 3c 25 88 00 00 00 00 0f 84 d4 01 00 00 49 89 f6 49 89 cc e8 [ 168.689818] RSP: 0018:ffffcdcb8200fb80 EFLAGS: 00010282 [ 168.690871] RAX: ffffffffaee74ec0 RBX: 0000000000000000 RCX: ffffffffb0120158 [ 168.692251] RDX: ffffcdcb8200fbe0 RSI: ffff88c187c9fa80 RDI: ffff88c186c98a80 [ 168.693593] RBP: ffffcdcb8200fbc0 R08: 0000000000000000 R09: 0000000000000000 [ 168.694941] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88c186c98a80 [ 168.696289] R13: 00007fff005aaa20 R14: 0000000000000080 R15: ffff88c188f4fce0 [ 168.697637] FS: 0000790e81c58280(0000) GS:ffff88c20a957000(0000) knlGS:0000000000000000 [ 168.699227] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 168.700349] CR2: 0000000000000088 CR3: 000000012fd3e000 CR4: 0000000000350ef0 [ 168.701696] Call Trace: [ 168.702325] [ 168.702995] rawdata_get_link_data+0x1c/0x30 [ 168.704145] vfs_readlink+0xd4/0x160 [ 168.705152] do_readlinkat+0x114/0x180 [ 168.706214] __x64_sys_readlink+0x1e/0x30 [ 168.708653] x64_sys_call+0x1d77/0x26b0 [ 168.709525] do_syscall_64+0x81/0x500 [ 168.710348] ? do_statx+0x72/0xb0 [ 168.711109] ? putname+0x3e/0x80 [ 168.711845] ? __x64_sys_statx+0xb7/0x100 [ 168.712711] ? x64_sys_call+0x10fc/0x26b0 [ 168.713577] ? do_syscall_64+0xbf/0x500 [ 168.714412] ? do_user_addr_fault+0x1d2/0x8d0 [ 168.715404] ? irqentry_exit+0xb2/0x740 [ 168.716359] ? exc_page_fault+0x90/0x1b0 [ 168.717307] entry_SYSCALL_64_after_hwframe+0x76/0x7e Fixes: 1180b4c757aab ("apparmor: fix dangling symlinks to policy rawdata after replacement") Signed-off-by: Georgia Garcia Signed-off-by: John Johansen Signed-off-by: Sasha Levin

apparmor: fix possible NULL pointer dereference

2024-09-08T05:53:07+00:00

[ Upstream commit 3dd384108d53834002be5630132ad5c3f32166ad ] 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: ? 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 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 Signed-off-by: John Johansen Signed-off-by: Sasha Levin

apparmor: fix a memleak in multi_transaction_new()

2022-12-31T12:32:29+00:00

[ Upstream commit c73275cf6834787ca090317f1d20dbfa3b7f05aa ] In multi_transaction_new(), the variable t is not freed or passed out on the failure of copy_from_user(t->data, buf, size), which could lead to a memleak. Fix this bug by adding a put_multi_transaction(t) in the error path. Fixes: 1dea3b41e84c5 ("apparmor: speed up transactional queries") Signed-off-by: Gaosheng Cui Signed-off-by: John Johansen Signed-off-by: Sasha Levin

apparmor: move ptrace mediation to more logical task.{h,c}

2022-07-19T11:14:22+00:00

AppArmor split out task oriented controls to their own logical file a while ago. Ptrace mediation is better grouped with task than ipc, so move it. Signed-off-by: John Johansen

apparmor: extend policydb permission set by making use of the xbits

2022-07-19T09:57:15+00:00

The policydb permission set has left the xbits unused. Make them available for mediation. Signed-off-by: John Johansen

apparmor: Fix memleak in aa_simple_write_to_buffer()

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

When copy_from_user failed, the memory is freed by kvfree. however the management struct and data blob are allocated independently, so only kvfree(data) cause a memleak issue here. Use aa_put_loaddata(data) to fix this issue. Fixes: a6a52579e52b5 ("apparmor: split load data into management struct and data blob") Signed-off-by: Xiu Jianfeng Signed-off-by: John Johansen

apparmor: Fix undefined reference to `zlib_deflate_workspacesize'

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

IF CONFIG_SECURITY_APPARMOR_EXPORT_BINARY is disabled, there remains some unneed references to zlib, and can result in undefined symbol references if ZLIB_INFLATE or ZLIB_DEFLATE are not defined. Reported-by: kernel test robot Fixes: abfb9c0725f2 ("apparmor: make export of raw binary profile to userspace optional") Signed-off-by: John Johansen