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CVE PROGRAM SOURCE RECORD7.1 High

CVE-2026-31699

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

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Status
Published
Published
Updated
Assigning organization
Linux

Description

In the Linux kernel, the following vulnerability has been resolved: crypto: ccp: Don't attempt to copy CSR to userspace if PSP command failed When retrieving the PEK CSR, don't attempt to copy the 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 2084 at addr ffff898144612e20 by task syz.9.219/21405 CPU: 14 UID: 0 PID: 21405 Comm: syz.9.219 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: <TASK> 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_pek_csr+0x31f/0x590 ../drivers/crypto/ccp/sev-dev.c:1872 sev_ioctl+0x3a4/0x490 ../drivers/crypto/ccp/sev-dev.c:2562 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 </TASK> 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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • e799035609e1526761aa2f896a974b233d04d36d to < 502d10a1d9d477e6c7fc7021a2dac7018f4ab8b5affected
  • e799035609e1526761aa2f896a974b233d04d36d to < 0fb87e44b81385f940b482cba5b3f0bd18fb8185affected
  • e799035609e1526761aa2f896a974b233d04d36d to < 372116eece159adff631b1508344c8b85ebf9559affected
  • e799035609e1526761aa2f896a974b233d04d36d to < 607ba280f2adb5092cf5386c3935afac2ca0031aaffected
  • e799035609e1526761aa2f896a974b233d04d36d to < 59e9ae81f8670ccc780bc75f45a355736f640ec9affected
  • e799035609e1526761aa2f896a974b233d04d36d to < 111dcc6d0f016076745824a787d25609d0022f4caffected
  • e799035609e1526761aa2f896a974b233d04d36d to < 3b4fd8f15765d9a3105b834dba8a05d025e5e16eaffected
  • e799035609e1526761aa2f896a974b233d04d36d to < abe4a6d6f606113251868c2c4a06ba904bb41eedaffected

Linux Linux

Default version status: affected

  • 4.16affected
  • 0 to < 4.16unaffected
  • 5.10.258 to ≤ 5.10.*unaffected
  • 5.15.209 to ≤ 5.15.*unaffected
  • 6.1.175 to ≤ 6.1.*unaffected
  • 6.6.136 to ≤ 6.6.*unaffected
  • 6.12.84 to ≤ 6.12.*unaffected
  • 6.18.25 to ≤ 6.18.*unaffected
  • 7.0.2 to ≤ 7.0.*unaffected
  • 7.1 to ≤ *unaffected

References