CVE-2026-80652

What the bug is

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>] sev_ioctl_do_pdh_export+0x559/0x7a0 drivers/crypto/ccp/sev-dev.c:2308 [<ffffffff853d1fdd>] sev_ioctl+0x2cd/0x480 drivers/crypto/ccp/sev-dev.c:2556 [<ffffffff82549ebc>] vfs_ioctl fs/ioctl.c:52 [inline] [<ffffffff82549ebc>] __do_sys_ioctl fs/ioctl.c:598 [inline] [<ffffffff82549ebc>] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:584 [<ffffffff8630115f>] do_syscall_x64 arch/x86/entry/syscall_64.c:64 [inline] [<ffffffff8630115f>] do_syscall_64+0x9f/0xf40 arch/x86/entry/syscall_64.c:98 [<ffffffff81000136>] entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fd3158eac39 </TASK> Thankfully, the bug is benign outside of CONFIG_DEBUG_VIRTUAL=y as getting the physical address is just arithmetic, and the PSP errors out before trying to write to the garbage address (which it must, otherwise querying the blob lengths would clobber memory at pfn=0).

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

drivers/crypto/ccp/sev-dev.c

What this is

AMD CRYPTOGRAPHIC COPROCESSOR (CCP) DRIVER - SEV SUPPORTMAINTAINERS section matched on drivers/crypto/ccp/sev* · linux-crypto@vger.kernel.org · Supported

Kernel module

ccp

Check it on the machine

grep -wE 'CONFIG_CRYPTO|CONFIG_CRYPTO_DEV_CCP|CONFIG_CRYPTO_DEV_CCP_DD|CONFIG_CRYPTO_DEV_SP_PSP' /boot/config-$(uname -r)

Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.

lsmod | grep -w ccp

Prints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.

Show whether Debian builds this, per release

Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.

• bookwormMnot built on amd64/cloud-amd64, arm64/arm64, arm64/cloud-arm64, arm64/rt/arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, i386/686, i386/686-pae, i386/rt/686-pae, ppc64el/powerpc64le
• trixieMnot built on amd64/cloud-amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt/arm64, armel/rpi, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
• forky, sidMnot built on amd64/cloud-amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt-arm64, armhf/armmp, armhf/armmp-lpae, loong64/loong64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x

M

a module where it is built at all; some flavours do not build it

Build switches

CONFIG_CRYPTO, CONFIG_CRYPTO_DEV_CCP, CONFIG_CRYPTO_DEV_CCP_DD, CONFIG_CRYPTO_DEV_SP_PSP

Reads as

all on means the file is compiled; any one off means it is not.

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages

Signals

Published

2026-08-28 (2 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.22%, higher than 11.6% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

drivers/crypto

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
4.16	5.10.261	1c587f30c624
4.16	5.15.212	13b4d5e055d3
4.16	6.1.178	94344bc7c9d7
4.16	6.6.145	50c3c7df4f26
4.16	6.12.97	ee717e73ab47
4.16	6.18.40	21650fe221ea
4.16	7.1.5	d88071a6ce09
4.16	7.2	ef8c9dacda28