Wind River Support Network

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.