Bug 2448753 (CVE-2026-23269)

Summary: CVE-2026-23269 kernel: apparmor: validate DFA start states are in bounds in unpack_pdb
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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OS: Linux   
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Description OSIDB Bzimport 2026-03-18 19:03:23 UTC 
In the Linux kernel, the following vulnerability has been resolved:

apparmor: validate DFA start states are in bounds in unpack_pdb

Start states are read from untrusted data and used as indexes into the
DFA state tables. The aa_dfa_next() function call in unpack_pdb() will
access dfa->tables[YYTD_ID_BASE][start], and if the start state exceeds
the number of states in the DFA, this results in an out-of-bound read.

==================================================================
 BUG: KASAN: slab-out-of-bounds in aa_dfa_next+0x2a1/0x360
 Read of size 4 at addr ffff88811956fb90 by task su/1097
 ...

Reject policies with out-of-bounds start states during unpacking
to prevent the issue.
Comment 1 Alexander B 2026-03-19 11:03:36 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026031846-CVE-2026-23269-2bf7@gregkh/T