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

Goal: 1000 CNY · Raised: 1336 CNY

100%
Buy Us a Coffee

CVE-2026-43497— fbdev: udlfb: add vm_ops to dlfb_ops_mmap to prevent use-after-free

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fbdev: udlfb中dlfb_ops_mmap未设置vm_ops，导致内核无法跟踪活动mmap，在USB断开时可能发生释放后重用。

CVSS 7.3 · High EPSS 0.11% · P2

Possible ATT&CK Techniques 1 AI

T1055.008 · Ptrace System Calls

Affected Version Matrix 18

VendorProduct Version RangeStatus
Linux Linux 7433914efd584b22bb49d3e1eee001f5d0525ecd< 60f711cfd580f86fea8284146ac133804e728f9a affected
7433914efd584b22bb49d3e1eee001f5d0525ecd< 5931f5651ee32bd41b3323256b31fcc8e71336ed affected
7433914efd584b22bb49d3e1eee001f5d0525ecd< e3d9865dacd7435b8465848428210d0f0c673311 affected
7433914efd584b22bb49d3e1eee001f5d0525ecd< 4f312c30f0368e8d2a76aa650dff73f23490b5e7 affected
7433914efd584b22bb49d3e1eee001f5d0525ecd< 18dd358de72d57993422cbb5dfb29ccd74efe192 affected
7433914efd584b22bb49d3e1eee001f5d0525ecd< da9b065cedfd3b574f229d5be594e6aa47a27ae6 affected
7433914efd584b22bb49d3e1eee001f5d0525ecd< a2c53a3822ee26e8d758071815b9ed3bf6669fc1 affected
7433914efd584b22bb49d3e1eee001f5d0525ecd< 8de779dc40d35d39fa07387b6f921eb11df0f511 affected
… +10 more rows
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-43497

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Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.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
fbdev: udlfb: add vm_ops to dlfb_ops_mmap to prevent use-after-free
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: fbdev: udlfb: add vm_ops to dlfb_ops_mmap to prevent use-after-free dlfb_ops_mmap() uses remap_pfn_range() to map vmalloc framebuffer pages to userspace but sets no vm_ops on the VMA. This means the kernel cannot track active mmaps. When dlfb_realloc_framebuffer() replaces the backing buffer via FBIOPUT_VSCREENINFO, existing mmap PTEs are not invalidated. On USB disconnect, dlfb_ops_destroy() calls vfree() on the old pages while userspace PTEs still reference them, resulting in a use-after-free: the process retains read/write access to freed kernel pages. Add vm_operations_struct with open/close callbacks that maintain an atomic mmap_count on struct dlfb_data. In dlfb_realloc_framebuffer(), check mmap_count and return -EBUSY if the buffer is currently mapped, preventing buffer replacement while userspace holds stale PTEs. Tested with PoC using dummy_hcd + raw_gadget USB device emulation.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/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fbdev: udlfb中dlfb_ops_mmap未设置vm_ops，导致内核无法跟踪活动mmap，在USB断开时可能发生释放后重用。
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)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux 7433914efd584b22bb49d3e1eee001f5d0525ecd ~ 60f711cfd580f86fea8284146ac133804e728f9a -
Linux Linux 4.19 -

II. Public POCs for CVE-2026-43497

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

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-43497

请登录查看更多情报信息。

Patches & Fixes for CVE-2026-43497 (8)

Same Patch Batch · Linux · 2026-05-21 · 8 CVEs total

CVE-2026-43501 9.8 CRITICAL ipv6: rpl: reserve mac_len headroom when recompressed SRH grows
CVE-2026-43495 8.8 HIGH net: wwan: t7xx: validate port_count against message length in t7xx_port_enum_msg_handler
CVE-2026-43502 7.8 HIGH net/rds: handle zerocopy send cleanup before the message is queued
CVE-2026-43498 7.8 HIGH accel/ivpu: Disallow re-exporting imported GEM objects
CVE-2026-43499 7.8 HIGH rtmutex: Use waiter::task instead of current in remove_waiter()
CVE-2026-43494 7.8 HIGH net/rds: reset op_nents when zerocopy page pin fails
CVE-2026-43496 net/sched: sch_red: Replace direct dequeue call with peek and qdisc_dequeue_peeked

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2026-43497

No comments yet

Leave a comment