CVE-2026-46254: AppArmor: Allow apparmor to handle unaligned dfa tables

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-03 · updated 2026-10-30

Description

In the Linux kernel, the following vulnerability has been resolved: AppArmor: Allow apparmor to handle unaligned dfa tables The dfa tables can originate from kernel or userspace and 8-byte alignment isn't always guaranteed and as such may trigger unaligned memory accesses on various architectures. Resulting in the following [ 73.901376] WARNING: CPU: 0 PID: 341 at security/apparmor/match.c:316 aa_dfa_unpack+0x6cc/0x720 [ 74.015867] Modules linked in: binfmt_misc evdev flash sg drm drm_panel_orientation_quirks backlight i2c_core configfs nfnetlink autofs4 ext4 crc16 mbcache jbd2 hid_generic usbhid sr_mod hid cdrom sd_mod ata_generic ohci_pci ehci_pci ehci_hcd ohci_hcd pata_ali libata sym53c8xx scsi_transport_spi tg3 scsi_mod usbcore libphy scsi_common mdio_bus usb_common [ 74.428977] CPU: 0 UID: 0 PID: 341 Comm: apparmor_parser Not tainted 6.18.0-rc6+ #9 NONE [ 74.536543] Call Trace: [ 74.568561] [<0000000000434c24>] dump_stack+0x8/0x18 [ 74.633757] [<0000000000476438>] __warn+0xd8/0x100 [ 74.696664] [<00000000004296d4>] warn_slowpath_fmt+0x34/0x74 [ 74.771006] [<00000000008db28c>] aa_dfa_unpack+0x6cc/0x720 [ 74.843062] [<00000000008e643c>] unpack_pdb+0xbc/0x7e0 [ 74.910545] [<00000000008e7740>] unpack_profile+0xbe0/0x1300 [ 74.984888] [<00000000008e82e0>] aa_unpack+0xe0/0x6a0 [ 75.051226] [<00000000008e3ec4>] aa_replace_profiles+0x64/0x1160 [ 75.130144] [<00000000008d4d90>] policy_update+0xf0/0x280 [ 75.201057] [<00000000008d4fc8>] profile_replace+0xa8/0x100 [ 75.274258] [<0000000000766bd0>] vfs_write+0x90/0x420 [ 75.340594] [<00000000007670cc>] ksys_write+0x4c/0xe0 [ 75.406932] [<0000000000767174>] sys_write+0x14/0x40 [ 75.472126] [<0000000000406174>] linux_sparc_syscall+0x34/0x44 [ 75.548802] ---[ end trace 0000000000000000 ]--- [ 75.609503] dfa blob stream 0xfff0000008926b96 not aligned. [ 75.682695] Kernel unaligned access at TPC[8db2a8] aa_dfa_unpack+0x6e8/0x720 Work around it by using the get_unaligned_xx() helpers.

Affected products

Linux kernel: from 4.11 before 6.12.75; from 6.13 before 6.18.14; from 6.19 before 6.19.4 — fixed in 6.12.75, 6.18.14, 6.19.4
Linux: 4.11 — fixed in 7.0

How to fix

Upgrade to a fixed version: Linux kernel 6.12.75, 6.18.14, 6.19.4; Linux 7.0. Check the vendor advisory for mitigations.

References

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