Bug 1227858 (CVE-2024-41005)

Summary: VUL-0: CVE-2024-41005: kernel: netpoll: fix race condition in netpoll_owner_active
Product: [Novell Products] SUSE Security Incidents Reporter: SMASH SMASH <smash_bz>
Component: IncidentsAssignee: Kernel Bugs <kernel-bugs>
Status: NEW --- QA Contact: Security Team bot <security-team>
Severity: Normal    
Priority: P3 - Medium CC: camila.matos
Version: unspecified   
Target Milestone: ---   
Hardware: Other   
OS: Other   
URL: https://smash.suse.de/issue/413932/
Whiteboard: CVSSv3.1:SUSE:CVE-2024-41005:5.8:(AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H)
Found By: Security Response Team Services Priority:
Business Priority: Blocker: ---
Marketing QA Status: --- IT Deployment: ---

Description SMASH SMASH 2024-07-15 16:49:53 UTC 
In the Linux kernel, the following vulnerability has been resolved:

netpoll: Fix race condition in netpoll_owner_active

KCSAN detected a race condition in netpoll:

	BUG: KCSAN: data-race in net_rx_action / netpoll_send_skb
	write (marked) to 0xffff8881164168b0 of 4 bytes by interrupt on cpu 10:
	net_rx_action (./include/linux/netpoll.h:90 net/core/dev.c:6712 net/core/dev.c:6822)
<snip>
	read to 0xffff8881164168b0 of 4 bytes by task 1 on cpu 2:
	netpoll_send_skb (net/core/netpoll.c:319 net/core/netpoll.c:345 net/core/netpoll.c:393)
	netpoll_send_udp (net/core/netpoll.c:?)
<snip>
	value changed: 0x0000000a -> 0xffffffff

This happens because netpoll_owner_active() needs to check if the
current CPU is the owner of the lock, touching napi->poll_owner
non atomically. The ->poll_owner field contains the current CPU holding
the lock.

Use an atomic read to check if the poll owner is the current CPU.

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-41005
https://www.cve.org/CVERecord?id=CVE-2024-41005
https://git.kernel.org/stable/c/3f1a155950a1685ffd0fd7175b3f671da8771f3d
https://git.kernel.org/stable/c/43c0ca793a18578a0f5b305dd77fcf7ed99f1265
https://git.kernel.org/stable/c/96826b16ef9c6568d31a1f6ceaa266411a46e46c
https://git.kernel.org/stable/c/a130e7da73ae93afdb4659842267eec734ffbd57
https://git.kernel.org/stable/c/c2e6a872bde9912f1a7579639c5ca3adf1003916
https://git.kernel.org/stable/c/efd29cd9c7b8369dfc7bcb34637e6bf1a188aa8e
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2024/CVE-2024-41005.mbox