Bug 1945373 (CVE-2021-29648)

Summary:	CVE-2021-29648 kernel: DoS due to BPF subsystem does not properly consider that resolved_ids and resolved_sizes are intentionally uninitialized in the vmlinux BPF
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, adscvr, airlied, alciregi, bdettelb, bhu, blc, bmasney, brdeoliv, bskeggs, chwhite, crwood, dhoward, dvlasenk, fhrbata, fpacheco, hdegoede, hkrzesin, jarodwilson, jeremy, jforbes, jglisse, jlelli, jonathan, josef, jshortt, jstancek, jwboyer, kcarcia, kernel-maint, kernel-mgr, lgoncalv, linville, masami256, mchehab, mlangsdo, nmurray, ptalbert, qzhao, rvrbovsk, steved, tomckay, walters, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	A flaw was found in the Linux kernel. The BPF subsystem does not properly consider that resolved_ids and resolved_sizes are intentionally uninitialized in the vmlinux BPF Type Format (BTF), which can cause a system crash upon an unexpected access attempt.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-04-06 16:10:43 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1945374, 1946676
Bug Blocks:	1945375

Description Guilherme de Almeida Suckevicz 2021-03-31 18:19:25 UTC

An issue was discovered in the Linux kernel before 5.11.11. The BPF subsystem does not properly consider that resolved_ids and resolved_sizes are intentionally uninitialized in the vmlinux BPF Type Format (BTF), which can cause a system crash upon an unexpected access attempt (in map_create in kernel/bpf/syscall.c or check_btf_info in kernel/bpf/verifier.c).

Reference and upstream patch:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=350a5c4dd2452ea999cc5e1d4a8dbf12de2f97ef

Comment 1 Guilherme de Almeida Suckevicz 2021-03-31 18:20:16 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1945374]

Comment 2 Fedora Update System 2021-04-02 00:17:15 UTC

FEDORA-2021-41fb54ae9f has been pushed to the Fedora 34 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 3 Fedora Update System 2021-04-02 01:14:24 UTC

FEDORA-2021-6b0f287b8b has been pushed to the Fedora 32 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 4 Fedora Update System 2021-04-02 01:21:28 UTC

FEDORA-2021-2306e89112 has been pushed to the Fedora 33 stable repository.
If problem still persists, please make note of it in this bug report.