kernel/linux.git/drivers/crypto/ccp/sev-dev.c, branch v7.1.7

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

2026-07-24T14:19:13+00:00

[ Upstream commit ef8c9dacda2871accd64e3eda951fef6b788b1ea ] 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: [] sev_ioctl_do_pdh_export+0x559/0x7a0 drivers/crypto/ccp/sev-dev.c:2308 [] sev_ioctl+0x2cd/0x480 drivers/crypto/ccp/sev-dev.c:2556 [] vfs_ioctl fs/ioctl.c:52 [inline] [] __do_sys_ioctl fs/ioctl.c:598 [inline] [] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:584 [] do_syscall_x64 arch/x86/entry/syscall_64.c:64 [inline] [] do_syscall_64+0x9f/0xf40 arch/x86/entry/syscall_64.c:98 [] entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fd3158eac39 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). Fixes: 76a2b524a4b1 ("crypto: ccp: Implement SEV_PDH_CERT_EXPORT ioctl command") Signed-off-by: Sean Christopherson Reviewed-by: Tom Lendacky Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin

crypto: ccp - Initialize data during __sev_snp_init_locked()

2026-07-24T14:19:10+00:00

[ Upstream commit fed613c1230277105bb512bce6e1fda8f316d178 ] Sashiko notes: > is the stack variable data left uninitialized when taking the else branch? > Since data.tio_en is later evaluated unconditionally, could stack garbage > cause it to evaluate to true, leading to erroneous attempts to allocate > pages and initialize SEV-TIO on unsupported hardware? If the firmware is too old to support SEV_INIT_EX, data is left uninitialized but used in the debug logging about whether TIO is enabled or not. Fixes: 4be423572da1 ("crypto/ccp: Implement SEV-TIO PCIe IDE (phase1)") Reported-by: Sashiko Assisted-by: Gemini:gemini-3.1-pro-preview Link: https://sashiko.dev/#/patchset/20260324161301.1353976-1-tycho%40kernel.org Signed-off-by: Tycho Andersen (AMD) Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin

crypto: ccp - Check for page allocation failure correctly in TIO

2026-07-24T14:19:10+00:00

[ Upstream commit a8d5370eef00eca132a292b1901c9914c817e385 ] Sashiko notes: > if __snp_alloc_firmware_pages() returns NULL under memory pressure, is it > safe to pass it directly to page_address()? > > On architectures without HASHED_PAGE_VIRTUAL, page_address(NULL) might > compute a deterministic but invalid, non-zero virtual address. The > subsequent if (tio_status) check would then evaluate to true, and > sev_tsm_init_locked() would dereference the invalid pointer. Indeed, page_address(NULL) will return non-NULL garbage here. Fix this by checking the page allocation itself for NULL, not the resulting virtual address. Fixes: 4be423572da1 ("crypto/ccp: Implement SEV-TIO PCIe IDE (phase1)") Reported-by: Sashiko Assisted-by: Gemini:gemini-3.1-pro-preview Link: https://sashiko.dev/#/patchset/20260324161301.1353976-1-tycho%40kernel.org Signed-off-by: Tycho Andersen (AMD) Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin

crypto: ccp - Fix snp_filter_reserved_mem_regions() off-by-one

2026-07-24T14:19:10+00:00

[ Upstream commit 1b864b6cb213bbd7b406e9b2e98c962077f300df ] Sashiko notes: > regarding the bounds check in snp_filter_reserved_mem_regions() > called via walk_iomem_res_desc(): does the check > if ((range_list->num_elements * 16 + 8) > PAGE_SIZE) > allow an off-by-one heap buffer overflow? > > If range_list->num_elements is 255, 255 * 16 + 8 = 4088, which is <= 4096. > Writing range->base (8 bytes) fills 4088-4095, but writing range->page_count > (4 bytes) would write to 4096-4099, overflowing the kzalloc-allocated > PAGE_SIZE buffer. Fix this by accounting for the entry about to be written to, in addition to the entries that are already allocated. Fixes: 1ca5614b84ee ("crypto: ccp: Add support to initialize the AMD-SP for SEV-SNP") Reported-by: Sashiko Assisted-by: Gemini:gemini-3.1-pro-preview Link: https://sashiko.dev/#/patchset/20260324161301.1353976-1-tycho%40kernel.org Signed-off-by: Tycho Andersen (AMD) Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin

crypto: ccp - Do not initialize SNP for ioctl(SNP_CONFIG)

2026-07-18T14:55:41+00:00

commit 08f0e65e784c4b20e6e620dd4f68d8636073a3d2 upstream. Sashiko notes: > if SEV initialization fails and KVM is actively running normal VMs, could a > userspace process trigger this code path via /dev/sev ioctls (e.g., > SEV_PDH_GEN) and zero out MSR_VM_HSAVE_PA globally? Would the next VMRUN > execution for an active VM trigger a general protection fault and crash the > host? Refuse to re-try initialization if SNP is not already initialized for SNP_CONFIG. This is technically an ABI break: before if SNP initialization failed it could be transparently retriggered by this ioctl, and if no VMs were running, everything worked fine. Hopefully this is enough of a corner case that nobody will notice, but someone does, there are a few options: * do something like symbol_get() for kvm and refuse to initialize if KVM is loaded * check each cpu's HSAVE_PA for non-zero data before re-initializing * once initialization has failed, continue to refuse to initialize until the ccp module is unloaded Fixes: ceac7fb89e8d ("crypto: ccp - Ensure implicit SEV/SNP init and shutdown in ioctls") Reported-by: Sashiko Assisted-by: Gemini:gemini-3.1-pro-preview Link: https://sashiko.dev/#/patchset/20260324161301.1353976-1-tycho%40kernel.org CC: Signed-off-by: Tycho Andersen (AMD) Reviewed-by: Tom Lendacky Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

crypto: ccp - Do not initialize SNP for ioctl(SNP_VLEK_LOAD)

2026-07-18T14:55:41+00:00

commit f91e9dbb5845d1e5abf1028e6df57dcf61583e1b upstream. Sashiko notes: > if SEV initialization fails and KVM is actively running normal VMs, could a > userspace process trigger this code path via /dev/sev ioctls (e.g., > SEV_PDH_GEN) and zero out MSR_VM_HSAVE_PA globally? Would the next VMRUN > execution for an active VM trigger a general protection fault and crash the > host? The SEV firmware docs for SNP_VLEK_LOAD note: > On SNP_SHUTDOWN, the VLEK is deleted. That is, the initialization/shutdown wrapper here is pointless, because the firmware immediately throws away the key anyway. Instead, refuse to do anything if SNP has not been previously initialized. This is an ABI break: before, this was a no-op and almost certainly a mistake by userspace, and now it returns -ENODEV. ABI compatibility could be maintained here by simply returning 0 in the check instead. Fixes: ceac7fb89e8d ("crypto: ccp - Ensure implicit SEV/SNP init and shutdown in ioctls") Reported-by: Sashiko Assisted-by: Gemini:gemini-3.1-pro-preview Link: https://sashiko.dev/#/patchset/20260324161301.1353976-1-tycho%40kernel.org CC: Signed-off-by: Tycho Andersen (AMD) Reviewed-by: Tom Lendacky Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

crypto: ccp - Do not initialize SNP for ioctl(SNP_COMMIT)

2026-07-18T14:55:41+00:00

commit 5a1364da2f04217a36e2fdfa2db4ee025b383a20 upstream. Sashiko notes: > if SEV initialization fails and KVM is actively running normal VMs, could a > userspace process trigger this code path via /dev/sev ioctls (e.g., > SEV_PDH_GEN) and zero out MSR_VM_HSAVE_PA globally? Would the next VMRUN > execution for an active VM trigger a general protection fault and crash the > host? The SNP_COMMIT command does not require the firmware to be in any particular state. Skip initializing it if it was previously uninitialized. The SEV-SNP firmware specification doc 56860 does not mention SNP_COMMIT in Table 5 as a command that is allowed in the UNINIT state, but it is in fact allowed and a future documentation update will reflect that. Fixes: ceac7fb89e8d ("crypto: ccp - Ensure implicit SEV/SNP init and shutdown in ioctls") Reported-by: Sashiko Assisted-by: Gemini:gemini-3.1-pro-preview Link: https://sashiko.dev/#/patchset/20260324161301.1353976-1-tycho%40kernel.org CC: Signed-off-by: Tycho Andersen (AMD) Reviewed-by: Tom Lendacky Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

crypto: ccp - Do not initialize SNP for SEV ioctls

2026-07-18T14:55:41+00:00

commit fb1758e74b8061aacfbce7bbb7a7cc650537e167 upstream. Sashiko notes: > if SEV initialization fails and KVM is actively running normal VMs, could a > userspace process trigger this code path via /dev/sev ioctls (e.g., > SEV_PDH_GEN) and zero out MSR_VM_HSAVE_PA globally? Would the next VMRUN > execution for an active VM trigger a general protection fault and crash the > host? sev_move_to_init_state() is called for ioctls requiring only SEV firmware: SEV_PEK_GEN, SEV_PDH_GEN, SEV_PEK_CSR, SEV_PEK_CERT_IMPORT, and SEV_PDH_CERT_EXPORT. After the firmware command, it does SEV_SHUTDOWN on the SEV firmware. Since these commands do not require SNP to be initialized, skip it by calling __sev_platform_init_locked() which only initializes the SEV firmware. This way SNP is not Initialized at all, and HSAVE_PA is not cleared. The previous code saved any SEV initialization firmware error to init_args.error and then threw it away and hardcoded the return value of INVALID_PLATFORM_STATE regardless of the real firmware error. This patch changes it to surface the underlying error, which is hopefully both more useful and doesn't cause any problems. Note that it is still safe to call __sev_firmware_shutdown() directly: it calls __sev_snp_shutdown_locked(), which skips SNP shutdown if SNP was not initialized. Fixes: ceac7fb89e8d ("crypto: ccp - Ensure implicit SEV/SNP init and shutdown in ioctls") Reported-by: Sashiko Assisted-by: Gemini:gemini-3.1-pro-preview Link: https://sashiko.dev/#/patchset/20260324161301.1353976-1-tycho%40kernel.org CC: Signed-off-by: Tycho Andersen (AMD) Reviewed-by: Tom Lendacky Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

crypto: ccp: Don't attempt to copy ID to userspace if PSP command failed

2026-04-16T09:33:04+00:00

When retrieving the ID for the CPU, don't attempt to copy the ID blob to userspace if the firmware command failed. If the failure was due to an invalid length, i.e. the userspace buffer+length was too small, copying the number of bytes _firmware_ requires will overflow the kernel-allocated buffer and leak data to userspace. BUG: KASAN: slab-out-of-bounds in instrument_copy_to_user ../include/linux/instrumented.h:129 [inline] BUG: KASAN: slab-out-of-bounds in _inline_copy_to_user ../include/linux/uaccess.h:205 [inline] BUG: KASAN: slab-out-of-bounds in _copy_to_user+0x66/0xa0 ../lib/usercopy.c:26 Read of size 64 at addr ffff8881867f5960 by task syz.0.906/24388 CPU: 130 UID: 0 PID: 24388 Comm: syz.0.906 Tainted: G U O 7.0.0-smp-DEV #28 PREEMPTLAZY Tainted: [U]=USER, [O]=OOT_MODULE Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 12.62.0-0 11/19/2025 Call Trace: dump_stack_lvl+0xc5/0x110 ../lib/dump_stack.c:120 print_address_description ../mm/kasan/report.c:378 [inline] print_report+0xbc/0x260 ../mm/kasan/report.c:482 kasan_report+0xa2/0xe0 ../mm/kasan/report.c:595 check_region_inline ../mm/kasan/generic.c:-1 [inline] kasan_check_range+0x264/0x2c0 ../mm/kasan/generic.c:200 instrument_copy_to_user ../include/linux/instrumented.h:129 [inline] _inline_copy_to_user ../include/linux/uaccess.h:205 [inline] _copy_to_user+0x66/0xa0 ../lib/usercopy.c:26 copy_to_user ../include/linux/uaccess.h:236 [inline] sev_ioctl_do_get_id2+0x361/0x490 ../drivers/crypto/ccp/sev-dev.c:2222 sev_ioctl+0x25f/0x490 ../drivers/crypto/ccp/sev-dev.c:2575 vfs_ioctl ../fs/ioctl.c:51 [inline] __do_sys_ioctl ../fs/ioctl.c:597 [inline] __se_sys_ioctl+0x11d/0x1b0 ../fs/ioctl.c:583 do_syscall_x64 ../arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe0/0x800 ../arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e WARN if the driver says the command succeeded, but the firmware error code says otherwise, as __sev_do_cmd_locked() is expected to return -EIO on any firwmware error. Reported-by: Alexander Potapenko Reported-by: Sebastian Alba Vives Fixes: d6112ea0cb34 ("crypto: ccp - introduce SEV_GET_ID2 command") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson Signed-off-by: Herbert Xu

crypto: ccp: Don't attempt to copy PDH cert to userspace if PSP command failed

2026-04-16T09:33:01+00:00

When retrieving the PDH cert, don't attempt to copy the blobs to userspace if the firmware command failed. If the failure was due to an invalid length, i.e. the userspace buffer+length was too small, copying the number of bytes _firmware_ requires will overflow the kernel-allocated buffer and leak data to userspace. BUG: KASAN: slab-out-of-bounds in instrument_copy_to_user ../include/linux/instrumented.h:129 [inline] BUG: KASAN: slab-out-of-bounds in _inline_copy_to_user ../include/linux/uaccess.h:205 [inline] BUG: KASAN: slab-out-of-bounds in _copy_to_user+0x66/0xa0 ../lib/usercopy.c:26 Read of size 2084 at addr ffff8885c4ab8aa0 by task syz.0.186/21033 CPU: 51 UID: 0 PID: 21033 Comm: syz.0.186 Tainted: G U O 7.0.0-smp-DEV #28 PREEMPTLAZY Tainted: [U]=USER, [O]=OOT_MODULE Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 34.84.12-0 11/17/2025 Call Trace: dump_stack_lvl+0xc5/0x110 ../lib/dump_stack.c:120 print_address_description ../mm/kasan/report.c:378 [inline] print_report+0xbc/0x260 ../mm/kasan/report.c:482 kasan_report+0xa2/0xe0 ../mm/kasan/report.c:595 check_region_inline ../mm/kasan/generic.c:-1 [inline] kasan_check_range+0x264/0x2c0 ../mm/kasan/generic.c:200 instrument_copy_to_user ../include/linux/instrumented.h:129 [inline] _inline_copy_to_user ../include/linux/uaccess.h:205 [inline] _copy_to_user+0x66/0xa0 ../lib/usercopy.c:26 copy_to_user ../include/linux/uaccess.h:236 [inline] sev_ioctl_do_pdh_export+0x3d3/0x7c0 ../drivers/crypto/ccp/sev-dev.c:2347 sev_ioctl+0x2a2/0x490 ../drivers/crypto/ccp/sev-dev.c:2568 vfs_ioctl ../fs/ioctl.c:51 [inline] __do_sys_ioctl ../fs/ioctl.c:597 [inline] __se_sys_ioctl+0x11d/0x1b0 ../fs/ioctl.c:583 do_syscall_x64 ../arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe0/0x800 ../arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e WARN if the driver says the command succeeded, but the firmware error code says otherwise, as __sev_do_cmd_locked() is expected to return -EIO on any firwmware error. Reported-by: Alexander Potapenko Reported-by: Sebastian Alba Vives Fixes: 76a2b524a4b1 ("crypto: ccp: Implement SEV_PDH_CERT_EXPORT ioctl command") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson Signed-off-by: Herbert Xu