CVE-2023-53111: linux kernel Use-After-Free — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: loop: Fix use-after-free issues do_req_filebacked() calls blk_mq_complete_request() synchronously or asynchronously when using asynchronous I/O unless memory allocation fails. Hence, modify loop_handle_cmd() such that it does not dereference 'cmd' nor 'rq' after do_req_filebacked() finished unless we are sure that the request has not yet been completed. This patch fixes the following kernel crash: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000054 Call trace: css_put.42938+0x1c/0x1ac loop_process_work+0xc8c/0xfd4 loop_rootcg_workfn+0x24/0x34 process_one_work+0x244/0x558 worker_thread+0x400/0x8fc kthread+0x16c/0x1e0 ret_from_fork+0x10/0x20

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CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-416 Use After Free

Affected Products

Vendor	Product	Versions
linux	linux_kernel	4.4 — 5.15.104
linux	linux_kernel	5.16 — 6.1.21
linux	linux_kernel	6.2 — 6.2.8
linux	linux_kernel	All
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/407badf73ec9fb0d5744bf2ca1745c1818aa222f https://git.kernel.org/stable/c/6917395c4667cfb607ed8bf1826205a59414657c https://git.kernel.org/stable/c/9b0cb770f5d7b1ff40bea7ca385438ee94570eec https://git.kernel.org/stable/c/e3fda704903f6d1fc351412f1bc6620333959ada

Frequently Asked Questions

What is CVE-2023-53111? +

In the Linux kernel, the following vulnerability has been resolved: loop: Fix use-after-free issues do_req_filebacked() calls blk_mq_complete_request() synchronously or asynchronously when using asynchronous I/O unless memory allocation fails. Hence, modify loop_handle_cmd() such that it does not dereference 'cmd' nor 'rq' after do_req_filebacked() finished unless we are sure that the request has not yet been completed. This patch fixes the following kernel crash: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000054 Call trace: css_put.42938+0x1c/0x1ac loop_process_work+0xc8c/0xfd4 loop_rootcg_workfn+0x24/0x34 process_one_work+0x244/0x558 worker_thread+0x400/0x8fc kthread+0x16c/0x1e0 ret_from_fork+0x10/0x20 It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2023-53111? +

CVE-2023-53111 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2023-53111? +

CVE-2023-53111 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2023-53111? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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