Bug 1227798 (CVE-2024-40909) - VUL-0: CVE-2024-40909: kernel: bpf: Fix a potential use-after-free in bpf_link_free()
Summary: VUL-0: CVE-2024-40909: kernel: bpf: Fix a potential use-after-free in bpf_lin...
Status: NEW
Alias: CVE-2024-40909
Product: SUSE Security Incidents
Classification: Novell Products
Component: Incidents (show other bugs)
Version: unspecified
Hardware: Other Other
: P3 - Medium : Normal
Target Milestone: ---
Assignee: Shung-Hsi Yu
QA Contact: Security Team bot
URL: https://smash.suse.de/issue/413836/
Whiteboard: CVSSv3.1:SUSE:CVE-2024-40909:6.7:(AV:...
Keywords:
Depends on:
Blocks:
 
Reported: 2024-07-15 12:38 UTC by SMASH SMASH
Modified: 2024-07-17 14:24 UTC (History)
3 users (show)

See Also:
Found By: Security Response Team
Services Priority:
Business Priority:
Blocker: ---
Marketing QA Status: ---
IT Deployment: ---

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Description SMASH SMASH 2024-07-15 12:38:52 UTC 
In the Linux kernel, the following vulnerability has been resolved:

bpf: Fix a potential use-after-free in bpf_link_free()

After commit 1a80dbcb2dba, bpf_link can be freed by
link->ops->dealloc_deferred, but the code still tests and uses
link->ops->dealloc afterward, which leads to a use-after-free as
reported by syzbot. Actually, one of them should be sufficient, so
just call one of them instead of both. Also add a WARN_ON() in case
of any problematic implementation.

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-40909
https://www.cve.org/CVERecord?id=CVE-2024-40909
https://git.kernel.org/stable/c/2884dc7d08d98a89d8d65121524bb7533183a63a
https://git.kernel.org/stable/c/91cff53136daeff50816b0baeafd38a6976f6209
https://git.kernel.org/stable/c/fa97b8fed9896f1e89cb657513e483a152d4c382
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2024/CVE-2024-40909.mbox