Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

crypto: ccp - Treat zero-length cert chain as query for blob lengths

When handling a PDH export, treat a zero-length userspace cert chain buffer as a request to query the length of the relevant blobs. Failure to account for the zero-length buffer trips a BUG_ON() when running with CONFIG_DEBUG_VIRTUAL=y due to trying to get the physical address of the ZERO_SIZE_PTR (returned by kzalloc() on the bogus allocation).

kernel BUG at arch/x86/mm/physaddr.c:28 ! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 30 UID: 0 PID: 28580 Comm: syz.2.18 Kdump: loaded Tainted: G W 6.18.16-smp-DEV #1 NONE Tainted: [W]=WARN Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 12.62.0-0 11/19/2025 RIP: 0010:__phys_addr+0x16a/0x180 arch/x86/mm/physaddr.c:28 RSP: 0018:ffffc9008329fc80 EFLAGS: 00010293 RAX: ffffffff8179110a RBX: 0000778000000010 RCX: ffff8884e6992600 RDX: 0000000000000000 RSI: 0000000080000010 RDI: 0000778000000010 RBP: ffffc9008329fdf0 R08: 0000000000000dc0 R09: 00000000ffffffff R10: dffffc0000000000 R11: fffffbfff126d297 R12: dffffc0000000000 R13: 1ffff92010653fc8 R14: 0000000080000010 R15: dffffc0000000000 FS: 0000555556bec9c0(0000) GS:ffff88aa4ce1c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd3159e7000 CR3: 00000004fbc44000 CR4: 0000000000350ef0 Call Trace: <TASK> [<ffffffff853d3869>]…