CVE-2026-46254

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 isnt 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 Software

References

• https://git.kernel.org/stable/c/23f112bd6144e815153462e12d313ac3e7027168
• https://git.kernel.org/stable/c/64802f731214a51dfe3c6c27636b3ddafd003eb0
• https://git.kernel.org/stable/c/cded636008bde2b397a7cf63b8299d7c303aaf6a
• https://git.kernel.org/stable/c/ec737e7fdf2f0ba7b203d4ec72cc915978b10e7e