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.
Exploitability
AV:LAC:LPR:LUI:NScope
S:UImpact
C:HI:NA:H7.1/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H