Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-89923— KVM: s390: Free guest debug data on vcpu destroy

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.

在 Linux 内核中，已修复以下漏洞： KVM: s390: 在 vCPU 销毁时释放来宾调试数据 此前仅从 中调用，即仅在用户空间修改或禁用调试时触发。如果硬件断点仍处于激活状态时 vCPU 被销毁（这是 VMM 正常退出或崩溃时的常见情况），则 、 以及所有 缓冲区会发生内存泄漏，因为通用 KVM 在 之后立即释放 vCPU。 该泄漏受 条目数限制，每个 vCPU 大约泄漏 8 KiB，但在虚拟机整个生命周期内是无界的。由于这些内存分配使用了 ，对应的内存计费会超出退出进程的生命周期，从而“钉住”（pin）即

AI Predicted 5.5 Difficulty: Hard EPSS 0.21% · P10

Affected Version Matrix 18

VendorProduct Version RangeStatus
Linux Linux 27291e2165b6de70c476b7b675308113edd69a60< 053f2068cf9b0654b651fed5ad7649d3deb982bf affected
27291e2165b6de70c476b7b675308113edd69a60< 6c996b12bbe4a6023076e8eee3cfaf2cc99db76c affected
27291e2165b6de70c476b7b675308113edd69a60< d6280fc540d8f4653c9b54a78cb747e128070f5e affected
27291e2165b6de70c476b7b675308113edd69a60< 544a5a665019cef394ce8bda97fa7a2cab253781 affected
27291e2165b6de70c476b7b675308113edd69a60< 9a32c4c6a6c23b7f5bf765eb5b83ba7f64a8ec63 affected
27291e2165b6de70c476b7b675308113edd69a60< b5acacfdb8966abff91836c1c5bd7da59d8a526e affected
27291e2165b6de70c476b7b675308113edd69a60< e4d8b7f176b976474e0800ba71ee2dfa3ce263c9 affected
27291e2165b6de70c476b7b675308113edd69a60< e7f698b09d4a7c36b299acf680fc50fe868e2bcd affected
… +10 more rows
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-89923

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
KVM: s390: Free guest debug data on vcpu destroy
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: KVM: s390: Free guest debug data on vcpu destroy kvm_s390_clear_bp_data() is only called from kvm_arch_vcpu_ioctl_set_guest_debug(), i.e. when user space changes or disables debugging. A vCPU that is destroyed while hardware breakpoints are still armed - the normal case when the VMM just exits or crashes - leaks hw_bp_info, hw_wp_info and all old_data buffers, since generic KVM frees the vCPU right after kvm_arch_vcpu_destroy(). That is bounded by MAX_BP_COUNT entries, so roughly 8 KiB per vCPU, but it is unbounded over VM lifetimes. The allocations are GFP_KERNEL_ACCOUNT, so the charge also outlives the exiting process and pins dying memcgs. Fix by clearing the debug data on vCPU destruction. Calling it unconditionally is fine: struct kvm_vcpu is zero allocated, so for a vCPU that never enabled debugging the counters are 0 and the pointers NULL.
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

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux 27291e2165b6de70c476b7b675308113edd69a60 ~ 053f2068cf9b0654b651fed5ad7649d3deb982bf -
Linux Linux 3.16 -

II. Public POCs for CVE-2026-89923

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-89923

请登录查看更多情报信息。

Other References for CVE-2026-89923 (8)

Same Patch Batch · Linux · 2026-09-16 · 276 CVEs total

CVE-2026-90048 9.8 CRITICAL fs/ntfs3: fix slab-out-of-bounds write in ni_create_attr_list()
CVE-2026-90012 9.8 CRITICAL spi: Fix DMA mapping ownership on partial map failure
CVE-2026-89970 9.8 CRITICAL nvmet-auth: Synchronize timeout work during SQ teardown
CVE-2026-89857 9.8 CRITICAL scsi: qla2xxx: Hold qpair lock when sending NVMe LS reject
CVE-2026-89969 9.8 CRITICAL nvmet-tcp: fix out-of-bounds write when receiving an over-long PDU
CVE-2026-89847 9.8 CRITICAL scsi: qla2xxx: Avoid double completion in async IOCB timeout
CVE-2026-89972 9.8 CRITICAL nvme: add missing SRCU grace period in error path
CVE-2026-89990 9.8 CRITICAL ceph: lock mutex in ceph_mds_check_access()
CVE-2026-90036 9.8 CRITICAL NFSD: Prevent client use-after-free during blocked-lock reaping
CVE-2026-90038 9.8 CRITICAL NFSD: Prevent client use-after-free during export state revocation
CVE-2026-90037 9.8 CRITICAL NFSD: Prevent client use-after-free during close_lru reaping
CVE-2026-89788 9.8 CRITICAL ksmbd: fix tree connection use-after-free in smb2_tree_connect()
CVE-2026-89783 9.8 CRITICAL xfrm6: fix out-of-bounds write in xfrm6_input_addr() when secpath is full
CVE-2026-90042 9.8 CRITICAL ceph: properly decrypt filenames in vmalloc() buffers
CVE-2026-89778 9.8 CRITICAL isofs: fix out-of-bounds page array access on empty zisofs block
CVE-2026-89915 9.3 CRITICAL KVM: arm64: Remove VM-wide VNCR mapping counter
CVE-2026-90049 9.3 CRITICAL net: skbuff: don't skb_tx_error() the source skb in skb_zerocopy()
CVE-2026-89775 9.3 CRITICAL KVM: arm64: Handle negative S1 walk levels in VNCR TLB size evaluation
CVE-2026-89916 9.3 CRITICAL KVM: arm64: Make VNCR invalidation participate in MMU invalidation retry
CVE-2026-89930 9.3 CRITICAL KVM: nVMX: Service local TLB flushes on failed nested VM-Enter

Showing top 20 of 276 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2026-89923

No comments yet

Leave a comment