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CVE-2026-52969— KVM: Reject wrapped offset in kvm_reset_dirty_gfn()

Quick assessment

Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Linux kernel是美国Linux基金会开源的操作系统Linux所使用的内核。 Linux kernel 5.11版本存在安全漏洞，该漏洞源于kvm_reset_dirty_gfn()函数中偏移量检查存在整数溢出，可能导致越界内存访问。

AI Predicted 6.5 Difficulty: Moderate EPSS 0.19% · P9

Affected Version Matrix 16

VendorProduct Version RangeStatus
Linux Linux fb04a1eddb1a65b6588a021bdc132270d5ae48bb< 74f1a22f7a80f03d28ad8551a2d25d563433addf affected
fb04a1eddb1a65b6588a021bdc132270d5ae48bb< 0eb281eb95b2d4eea4db1da5fe91023aecc97095 affected
fb04a1eddb1a65b6588a021bdc132270d5ae48bb< 01b71b930f15728aa8599478a7ce90c19dcd9fc2 affected
fb04a1eddb1a65b6588a021bdc132270d5ae48bb< b315b033a877b1ee6d827810b5d7bb4392ffcf8d affected
fb04a1eddb1a65b6588a021bdc132270d5ae48bb< 0d419c23bb11b5c9664de777c47c1f04a235882d affected
fb04a1eddb1a65b6588a021bdc132270d5ae48bb< ecf9b3ea7847fe14f34b8c41f00de1eb95c747da affected
fb04a1eddb1a65b6588a021bdc132270d5ae48bb< 577a8d3bae0531f0e5ccfac919cd8192f920a804 affected
5.11 affected
… +8 more rows
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I. Basic Information for CVE-2026-52969

Vulnerability Information
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Vulnerability Title
KVM: Reject wrapped offset in kvm_reset_dirty_gfn()
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: KVM: Reject wrapped offset in kvm_reset_dirty_gfn() kvm_reset_dirty_gfn() guards the gfn range with if (!memslot || (offset + __fls(mask)) >= memslot->npages) return; but offset is u64 and the addition is unchecked. The check can be silently bypassed by a u64 wrap. The dirty ring backing those entries is MAP_SHARED at KVM_DIRTY_LOG_PAGE_OFFSET of the vcpu fd, so the VMM can rewrite the slot and offset fields of any entry between when the kernel pushes them and when KVM_RESET_DIRTY_RINGS consumes them. On reset, kvm_dirty_ring_reset() re-reads the values via READ_ONCE() and feeds them straight back into this check; only the flags handshake is treated as the handover, the slot/offset payload is taken on trust. Crafting two entries entry[i].offset = 0xffffffffffffffc1 entry[i+1].offset = 0 makes the coalescing loop in kvm_dirty_ring_reset() compute delta = (s64)(0 - 0xffffffffffffffc1) = 63 which falls in [0, BITS_PER_LONG), so it folds entry[i+1] into the existing mask by setting bit 63. The trailing kvm_reset_dirty_gfn() call then sees offset = 0xffffffffffffffc1 and __fls(mask) = 63; the sum is 0 in u64 and the bounds check passes. That offset propagates into kvm_arch_mmu_enable_log_dirty_pt_masked() unchanged. On the legacy MMU path -- kvm_memslots_have_rmaps() == true, i.e. shadow paging, any VM that has allocated shadow roots, or a write-tracked slot -- it reaches gfn_to_rmap(), which indexes slot->arch.rmap[0][] with a near-U64_MAX gfn. That is an out-of-bounds load of a kvm_rmap_head, followed by a conditional clear of PT_WRITABLE_MASK in whatever the loaded pointer points at. The path is reachable from any process holding /dev/kvm. Range-check offset on its own first, so the addition cannot wrap. memslot->npages is bounded well below U64_MAX, so once offset < npages holds, offset + __fls(mask) (with __fls(mask) < BITS_PER_LONG) stays in range.
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Vulnerability Title
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会开源的操作系统Linux所使用的内核。 Linux kernel 5.11版本存在安全漏洞，该漏洞源于kvm_reset_dirty_gfn()函数中偏移量检查存在整数溢出，可能导致越界内存访问。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux fb04a1eddb1a65b6588a021bdc132270d5ae48bb ~ 74f1a22f7a80f03d28ad8551a2d25d563433addf -
Linux Linux 5.11 -

II. Public POCs for CVE-2026-52969

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III. Intelligence Information for CVE-2026-52969

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Patches & Fixes for CVE-2026-52969 (6)

Same Patch Batch · Linux · 2026-06-24 · 219 CVEs total

CVE-2026-53049 9.8 CRITICAL gfs2: add some missing log locking
CVE-2026-52993 9.8 CRITICAL tipc: fix double-free in tipc_buf_append()
CVE-2026-52989 9.8 CRITICAL nvmet-tcp: propagate nvmet_tcp_build_pdu_iovec() errors to its callers
CVE-2026-52986 9.8 CRITICAL netfilter: nf_conntrack_sip: don't use simple_strtoul
CVE-2026-52982 9.8 CRITICAL net: usb: rtl8150: fix use-after-free in rtl8150_start_xmit()
CVE-2026-53002 9.8 CRITICAL netfilter: conntrack: remove sprintf usage
CVE-2026-53006 9.8 CRITICAL ipv6: fix possible UAF in icmpv6_rcv()
CVE-2026-53045 9.8 CRITICAL memory: tegra124-emc: Fix dll_change check
CVE-2026-53086 9.8 CRITICAL net: bcmgenet: fix racing timeout handler
CVE-2026-53046 9.8 CRITICAL ksmbd: fix use-after-free from async crypto on Qualcomm crypto engine
CVE-2026-52955 9.8 CRITICAL libceph: Fix potential out-of-bounds access in crush_decode()
CVE-2026-53010 9.8 CRITICAL ksmbd: fix use-after-free in smb2_open during durable reconnect
CVE-2026-53088 9.8 CRITICAL net: bcmgenet: fix off-by-one in bcmgenet_put_txcb
CVE-2026-52914 9.8 CRITICAL batman-adv: fix fragment reassembly length accounting
CVE-2026-53055 9.8 CRITICAL crypto: hisilicon/sec2 - prevent req used-after-free for sec
CVE-2026-52924 9.8 CRITICAL sctp: purge outqueue on stale COOKIE-ECHO handling
CVE-2026-52931 9.8 CRITICAL batman-adv: tp_meter: avoid use of uninit sender vars
CVE-2026-52999 9.1 CRITICAL netfilter: nfnetlink_osf: fix out-of-bounds read on option matching
CVE-2026-53043 9.1 CRITICAL ocfs2/dlm: validate qr_numregions in dlm_match_regions()
CVE-2026-52958 9.1 CRITICAL libceph: Fix potential out-of-bounds access in osdmap_decode()

Showing top 20 of 219 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2026-52969

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