CVE-2026-46254 AppArmor: Allow apparmor to handle unaligned dfa tables
A missing alignment check in AppArmor DFA table handling causes kernel warnings and potential instability on architectures requiring strict alignment.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-46254?
CVE-2026-46254 is a medium-severity vulnerability in Linux kernel, published on 3 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-46254?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-46254?
Apply the vendor's patch.
Is CVE-2026-46254 being exploited?
There is no known exploitation of CVE-2026-46254 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-89342, BELL-CVE-2026-46254, DEBIAN-CVE-2026-46254, GHSA-7rpr-5c67-jf73, ROOT-OS-DEBIAN-11-CVE-2026-46254, ROOT-OS-DEBIAN-12-CVE-2026-46254 and 2 more.