CVE-2021-47230
published 2024-05-21CVE-2021-47230: In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Immediately reset the MMU context when the SMM flag is cleared Immediately reset…
PriorityP424medium6.6CVSS 3.1
AVLACLPRLUIRSUCNIHAH
EPSS
0.23%
14.2th percentile
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Immediately reset the MMU context when the SMM flag is cleared
Immediately reset the MMU context when the vCPU's SMM flag is cleared so
that the SMM flag in the MMU role is always synchronized with the vCPU's
flag. If RSM fails (which isn't correctly emulated), KVM will bail
without calling post_leave_smm() and leave the MMU in a bad state.
The bad MMU role can lead to a NULL pointer dereference when grabbing a
shadow page's rmap for a page fault as the initial lookups for the gfn
will happen with the vCPU's SMM flag (=0), whereas the rmap lookup will
use the shadow page's SMM flag, which comes from the MMU (=1). SMM has
an entirely different set of memslots, and so the initial lookup can find
a memslot (SMM=0) and then explode on the rmap memslot lookup (SMM=1).
general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 8410 Comm: syz-executor382 Not tainted 5.13.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__gfn_to_rmap arch/x86/kvm/mmu/mmu.c:935 [inline]
RIP: 0010:gfn_to_rmap+0x2b0/0x4d0 arch/x86/kvm/mmu/mmu.c:947
Code: 80 3c 20 00 74 08 4c 89 ff e8 f1 79 a9 00 4c 89 fb 4d 8b 37 44
RSP: 0018:ffffc90000ffef98 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888015b9f414 RCX: ffff888019669c40
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: 0000000000000001 R08: ffffffff811d9cdb R09: ffffed10065a6002
R10: ffffed10065a6002 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000003 R14: 0000000000000001 R15: 0000000000000000
FS: 000000000124b300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000028e31000 CR4: 00000000001526e0
DR0: 0000000000000000 DR1: 0000000000000000
Affected
14 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | linux | < linux 5.10.46-1 (bookworm) | linux 5.10.46-1 (bookworm) |
| linux | linux | — | — |
| linux | linux | >= 9ec19493fb86d6d5fbf9286b94ff21e56ef66376 < cbb425f62df9df7abee4b3f068f7ed6ffc3561e2 | cbb425f62df9df7abee4b3f068f7ed6ffc3561e2 |
| linux | linux | >= 9ec19493fb86d6d5fbf9286b94ff21e56ef66376 < 669a8866e468fd020d34eb00e08cb41d3774b71b | 669a8866e468fd020d34eb00e08cb41d3774b71b |
| linux | linux | >= 9ec19493fb86d6d5fbf9286b94ff21e56ef66376 < df9a40cfb3be2cbeb1c17bb67c59251ba16630f3 | df9a40cfb3be2cbeb1c17bb67c59251ba16630f3 |
| linux | linux | >= 9ec19493fb86d6d5fbf9286b94ff21e56ef66376 < 78fcb2c91adfec8ce3a2ba6b4d0dda89f2f4a7c6 | 78fcb2c91adfec8ce3a2ba6b4d0dda89f2f4a7c6 |
| linux | linux_kernel | — | — |
| linux | linux_kernel | >= 0 < 5.10.46-1 | 5.10.46-1 |
| linux | linux_kernel | >= 0 < 5.10.46-1 | 5.10.46-1 |
| linux | linux_kernel | >= 0 < 5.10.46-1 | 5.10.46-1 |
| linux | linux_kernel | >= 0 < 5.10.46-1 | 5.10.46-1 |
| linux | linux_kernel | >= 5.1 < 5.4.128 | 5.4.128 |
| linux | linux_kernel | >= 5.11 < 5.12.13 | 5.12.13 |
| linux | linux_kernel | >= 5.5 < 5.10.46 | 5.10.46 |
CVSS provenance
nvdv3.16.6MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:H
osv6.6MEDIUM
vendor_debian6.6MEDIUM
vendor_redhat6.6MEDIUM
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Red Hat
kernel: KVM: x86: Immediately reset the MMU context when the SMM flag is cleared
vendor_redhat·2024-05-21·CVSS 6.6
CVE-2021-47230 [MEDIUM] CWE-476 kernel: KVM: x86: Immediately reset the MMU context when the SMM flag is cleared
kernel: KVM: x86: Immediately reset the MMU context when the SMM flag is cleared
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Immediately reset the MMU context when the SMM flag is cleared
Immediately reset the MMU context when the vCPU's SMM flag is cleared so
that the SMM flag in the MMU role is always synchronized with the vCPU's
flag. If RSM fails (which isn't correctly emulated), KVM will bail
without calling post_leave_smm() and leave the MMU in a bad state.
The bad MMU role can lead to a NULL pointer dereference when grabbing a
shadow page's rmap for a page fault as the initial lookups for the gfn
will happen with the vCPU's SMM flag (=0), whereas the rmap lookup will
use the shadow page's SMM flag, which comes from the MMU (=1). SMM has
an entirely
Debian
CVE-2021-47230: linux - In the Linux kernel, the following vulnerability has been resolved: KVM: x86: I...
vendor_debian·2021·CVSS 6.6
CVE-2021-47230 [MEDIUM] CVE-2021-47230: linux - In the Linux kernel, the following vulnerability has been resolved: KVM: x86: I...
In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Immediately reset the MMU context when the SMM flag is cleared Immediately reset the MMU context when the vCPU's SMM flag is cleared so that the SMM flag in the MMU role is always synchronized with the vCPU's flag. If RSM fails (which isn't correctly emulated), KVM will bail without calling post_leave_smm() and leave the MMU in a bad state. The bad MMU role can lead to a NULL pointer dereference when grabbing a shadow page's rmap for a page fault as the initial lookups for the gfn will happen with the vCPU's SMM flag (=0), whereas the rmap lookup will use the shadow page's SMM flag, which comes from the MMU (=1). SMM has an entirely different set of memslots, and so the initial lookup can find a memslot (SMM=0) a
GHSA
GHSA-j8hx-6rxw-p4r9: In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Immediately reset the MMU context when the SMM flag is cleared
Immedia
ghsa_unreviewed·2024-05-21
CVE-2021-47230 [MEDIUM] CWE-476 GHSA-j8hx-6rxw-p4r9: In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Immediately reset the MMU context when the SMM flag is cleared
Immedia
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Immediately reset the MMU context when the SMM flag is cleared
Immediately reset the MMU context when the vCPU's SMM flag is cleared so
that the SMM flag in the MMU role is always synchronized with the vCPU's
flag. If RSM fails (which isn't correctly emulated), KVM will bail
without calling post_leave_smm() and leave the MMU in a bad state.
The bad MMU role can lead to a NULL pointer dereference when grabbing a
shadow page's rmap for a page fault as the initial lookups for the gfn
will happen with the vCPU's SMM flag (=0), whereas the rmap lookup will
use the shadow page's SMM flag, which comes from the MMU (=1). SMM has
an entirely different set of memslots, and so the initial lookup can find
a memslot (SMM=0
OSV
CVE-2021-47230: In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Immediately reset the MMU context when the SMM flag is cleared Immediate
osv·2024-05-21·CVSS 6.6
CVE-2021-47230 [MEDIUM] CVE-2021-47230: In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Immediately reset the MMU context when the SMM flag is cleared Immediate
In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Immediately reset the MMU context when the SMM flag is cleared Immediately reset the MMU context when the vCPU's SMM flag is cleared so that the SMM flag in the MMU role is always synchronized with the vCPU's flag. If RSM fails (which isn't correctly emulated), KVM will bail without calling post_leave_smm() and leave the MMU in a bad state. The bad MMU role can lead to a NULL pointer dereference when grabbing a shadow page's rmap for a page fault as the initial lookups for the gfn will happen with the vCPU's SMM flag (=0), whereas the rmap lookup will use the shadow page's SMM flag, which comes from the MMU (=1). SMM has an entirely different set of memslots, and so the initial lookup can find a memslot (SMM=0) a
No detection rules found.
No public exploits indexed.
https://git.kernel.org/stable/c/669a8866e468fd020d34eb00e08cb41d3774b71bhttps://git.kernel.org/stable/c/78fcb2c91adfec8ce3a2ba6b4d0dda89f2f4a7c6https://git.kernel.org/stable/c/cbb425f62df9df7abee4b3f068f7ed6ffc3561e2https://git.kernel.org/stable/c/df9a40cfb3be2cbeb1c17bb67c59251ba16630f3https://git.kernel.org/stable/c/669a8866e468fd020d34eb00e08cb41d3774b71bhttps://git.kernel.org/stable/c/78fcb2c91adfec8ce3a2ba6b4d0dda89f2f4a7c6https://git.kernel.org/stable/c/cbb425f62df9df7abee4b3f068f7ed6ffc3561e2https://git.kernel.org/stable/c/df9a40cfb3be2cbeb1c17bb67c59251ba16630f3
2024-05-21
Published