{"id":"DEBIAN-CVE-2021-47390","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).","modified":"2026-09-15T09:02:35.708922767Z","published":"2024-05-21T15:15:24.397Z","upstream":["CVE-2021-47390"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2021-47390"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.14.12-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2021-47390.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.14.12-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2021-47390.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.14.12-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2021-47390.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H"}]}