{"id":"DEBIAN-CVE-2021-47217","details":"In the Linux kernel, the following vulnerability has been resolved:  x86/hyperv: Fix NULL deref in set_hv_tscchange_cb() if Hyper-V setup fails  Check for a valid hv_vp_index array prior to derefencing hv_vp_index when setting Hyper-V's TSC change callback.  If Hyper-V setup failed in hyperv_init(), the kernel will still report that it's running under Hyper-V, but will have silently disabled nearly all functionality.    BUG: kernel NULL pointer dereference, address: 0000000000000010   #PF: supervisor read access in kernel mode   #PF: error_code(0x0000) - not-present page   PGD 0 P4D 0   Oops: 0000 [#1] SMP   CPU: 4 PID: 1 Comm: swapper/0 Not tainted 5.15.0-rc2+ #75   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015   RIP: 0010:set_hv_tscchange_cb+0x15/0xa0   Code: \u003c8b\u003e 04 82 8b 15 12 17 85 01 48 c1 e0 20 48 0d ee 00 01 00 f6 c6 08   ...   Call Trace:    kvm_arch_init+0x17c/0x280    kvm_init+0x31/0x330    vmx_init+0xba/0x13a    do_one_initcall+0x41/0x1c0    kernel_init_freeable+0x1f2/0x23b    kernel_init+0x16/0x120    ret_from_fork+0x22/0x30","modified":"2026-09-15T09:02:35.363193175Z","published":"2024-04-10T19:15:48.813Z","upstream":["CVE-2021-47217"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2021-47217"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.15.5-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2021-47217.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.15.5-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2021-47217.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.15.5-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2021-47217.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:N/I:N/A:H"}]}