CVE-2021-47390
- Source
- https://cve.org/CVERecord?id=CVE-2021-47390
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-47390.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2021-47390
- Downstream
- Related
- Published
- 2024-05-21T15:15:24Z
- Modified
- 2026-03-14T14:59:09Z
- Severity
-
- 7.1 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H CVSS Calculator
- Summary
- [none]
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Fix stack-out-of-bounds memory access from ioapic_write_indirect()
KASAN reports the following issue:
BUG: KASAN: stack-out-of-bounds in kvm_make_vcpus_request_mask+0x174/0x440 [kvm] Read of size 8 at addr ffffc9001364f638 by task qemu-kvm/4798
CPU: 0 PID: 4798 Comm: qemu-kvm Tainted: G X --------- --- Hardware name: AMD Corporation DAYTONA_X/DAYTONA_X, BIOS RYM0081C 07/13/2020 Call Trace: dump_stack+0xa5/0xe6 print_address_description.constprop.0+0x18/0x130 ? kvm_make_vcpus_request_mask+0x174/0x440 [kvm] __kasan_report.cold+0x7f/0x114 ? kvm_make_vcpus_request_mask+0x174/0x440 [kvm] kasan_report+0x38/0x50 kasan_check_range+0xf5/0x1d0 kvm_make_vcpus_request_mask+0x174/0x440 [kvm] kvm_make_scan_ioapic_request_mask+0x84/0xc0 [kvm] ? kvm_arch_exit+0x110/0x110 [kvm] ? sched_clock+0x5/0x10 ioapic_write_indirect+0x59f/0x9e0 [kvm] ? static_obj+0xc0/0xc0 ? __lock_acquired+0x1d2/0x8c0 ? kvm_ioapic_eoi_inject_work+0x120/0x120 [kvm]
The problem appears to be that 'vcpu_bitmap' is allocated as a single long on stack and it should really be KVM_MAX_VCPUS long. We also seem to clear the lower 16 bits of it with bitmap_zero() for no particular reason (my guess would be that 'bitmap' and 'vcpu_bitmap' variables in kvm_bitmap_or_dest_vcpus() caused the confusion: while the later is indeed 16-bit long, the later should accommodate all possible vCPUs).
- References
Affected packages
Git /
Database specific
source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-47390.json"
unresolved_ranges
[
{
"events": [
{
"introduced": "5.5"
},
{
"fixed": "5.10.71"
}
]
},
{
"events": [
{
"introduced": "5.11"
},
{
"fixed": "5.14.10"
}
]
},
{
"events": [
{
"introduced": "0"
},
{
"last_affected": "5.15-rc1"
}
]
},
{
"events": [
{
"introduced": "0"
},
{
"last_affected": "5.15-rc2"
}
]
},
{
"events": [
{
"introduced": "0"
},
{
"last_affected": "5.15-rc3"
}
]
}
]