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CVE-2026-31589— mm: call ->free_folio() directly in folio_unmap_invalidate()

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基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于在folio_unmap_invalidate()中调用filemap_free_folio()时未持有映射引用或锁，映射可能在访问mapping->a_ops时被移除，导致释放后重用。

CVSS 9.8 · Critical EPSS 0.44% · P37

Possible ATT&CK Techniques 1 AI

T1211 · Exploitation for Stealth

Affected Version Matrix 10

VendorProduct Version RangeStatus
Linux Linux fb7d3bc4149395c1ae99029c852eab6c28fc3c88< efc52947247a21bbf79059539bbbd40f4ea76f00 affected
fb7d3bc4149395c1ae99029c852eab6c28fc3c88< b667df39d98a7a24be7c2a40ff0863dac1ad2cd7 affected
fb7d3bc4149395c1ae99029c852eab6c28fc3c88< c330e65ea59c4805d6ab6757c4ddfe8c63acef31 affected
fb7d3bc4149395c1ae99029c852eab6c28fc3c88< 615d9bb2ccad42f9e21d837431e401db2e471195 affected
6.14 affected
< 6.14 unaffected
6.18.27≤ 6.18.* unaffected
6.19.14≤ 6.19.* unaffected
… +2 more rows
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I. Basic Information for CVE-2026-31589

Vulnerability Information
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Vulnerability Title
mm: call ->free_folio() directly in folio_unmap_invalidate()
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: mm: call ->free_folio() directly in folio_unmap_invalidate() We can only call filemap_free_folio() if we have a reference to (or hold a lock on) the mapping. Otherwise, we've already removed the folio from the mapping so it no longer pins the mapping and the mapping can be removed, causing a use-after-free when accessing mapping->a_ops. Follow the same pattern as __remove_mapping() and load the free_folio function pointer before dropping the lock on the mapping. That lets us make filemap_free_folio() static as this was the only caller outside filemap.c.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于在folio_unmap_invalidate()中调用filemap_free_folio()时未持有映射引用或锁，映射可能在访问mapping->a_ops时被移除，导致释放后重用。
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)

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Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux fb7d3bc4149395c1ae99029c852eab6c28fc3c88 ~ efc52947247a21bbf79059539bbbd40f4ea76f00 -
Linux Linux 6.14 -

II. Public POCs for CVE-2026-31589

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III. Intelligence Information for CVE-2026-31589

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Patches & Fixes for CVE-2026-31589 (2)

Same Patch Batch · Linux · 2026-04-24 · 138 CVEs total

CVE-2026-31633 9.8 CRITICAL rxrpc: Fix integer overflow in rxgk_verify_response()
CVE-2026-31637 9.8 CRITICAL rxrpc: reject undecryptable rxkad response tickets
CVE-2026-31536 9.8 CRITICAL smb: server: let send_done handle a completion without IB_SEND_SIGNALED
CVE-2026-31669 9.8 CRITICAL mptcp: fix slab-use-after-free in __inet_lookup_established
CVE-2026-31668 9.8 CRITICAL seg6: separate dst_cache for input and output paths in seg6 lwtunnel
CVE-2026-31649 9.8 CRITICAL net: stmmac: fix integer underflow in chain mode
CVE-2026-31607 9.8 CRITICAL usbip: validate number_of_packets in usbip_pack_ret_submit()
CVE-2026-31608 9.8 CRITICAL smb: server: avoid double-free in smb_direct_free_sendmsg after smb_direct_flush_send_list
CVE-2026-31609 9.8 CRITICAL smb: client: avoid double-free in smbd_free_send_io() after smbd_send_batch_flush()
CVE-2026-31657 9.8 CRITICAL batman-adv: hold claim backbone gateways by reference
CVE-2026-31659 9.8 CRITICAL batman-adv: reject oversized global TT response buffers
CVE-2026-31636 9.1 CRITICAL rxrpc: fix RESPONSE authenticator parser OOB read
CVE-2026-31629 8.8 HIGH nfc: llcp: add missing return after LLCP_CLOSED checks
CVE-2026-31588 8.8 HIGH KVM: x86: Use scratch field in MMIO fragment to hold small write values
CVE-2026-31570 8.8 HIGH can: gw: fix OOB heap access in cgw_csum_crc8_rel()
CVE-2026-31558 8.8 HIGH LoongArch: KVM: Make kvm_get_vcpu_by_cpuid() more robust
CVE-2026-31553 8.8 HIGH KVM: arm64: Fix the descriptor address in __kvm_at_swap_desc()
CVE-2026-31622 8.8 HIGH NFC: digital: Bounds check NFC-A cascade depth in SDD response handler
CVE-2026-31611 8.6 HIGH ksmbd: require 3 sub-authorities before reading sub_auth[2]
CVE-2026-31631 8.2 HIGH rxrpc: Fix buffer overread in rxgk_do_verify_authenticator()

Showing top 20 of 138 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

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