Bug 2300511 (CVE-2024-42073)

Summary:	CVE-2024-42073 kernel: mlxsw: spectrum_buffers: Fix memory corruptions on Spectrum-4 systems
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	dfreiber, drow, jburrell, vkumar
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	kernel 6.1.97, kernel 6.6.37, kernel 6.9.8, kernel 6.10	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:		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:	2301708
Bug Blocks:

Description OSIDB Bzimport 2024-07-29 16:27:30 UTC

In the Linux kernel, the following vulnerability has been resolved:

mlxsw: spectrum_buffers: Fix memory corruptions on Spectrum-4 systems

The following two shared buffer operations make use of the Shared Buffer
Status Register (SBSR):

 # devlink sb occupancy snapshot pci/0000:01:00.0
 # devlink sb occupancy clearmax pci/0000:01:00.0

The register has two masks of 256 bits to denote on which ingress /
egress ports the register should operate on. Spectrum-4 has more than
256 ports, so the register was extended by cited commit with a new
'port_page' field.

However, when filling the register's payload, the driver specifies the
ports as absolute numbers and not relative to the first port of the port
page, resulting in memory corruptions [1].

Fix by specifying the ports relative to the first port of the port page.

[1]
BUG: KASAN: slab-use-after-free in mlxsw_sp_sb_occ_snapshot+0xb6d/0xbc0
Read of size 1 at addr ffff8881068cb00f by task devlink/1566
[...]
Call Trace:
 <TASK>
 dump_stack_lvl+0xc6/0x120
 print_report+0xce/0x670
 kasan_report+0xd7/0x110
 mlxsw_sp_sb_occ_snapshot+0xb6d/0xbc0
 mlxsw_devlink_sb_occ_snapshot+0x75/0xb0
 devlink_nl_sb_occ_snapshot_doit+0x1f9/0x2a0
 genl_family_rcv_msg_doit+0x20c/0x300
 genl_rcv_msg+0x567/0x800
 netlink_rcv_skb+0x170/0x450
 genl_rcv+0x2d/0x40
 netlink_unicast+0x547/0x830
 netlink_sendmsg+0x8d4/0xdb0
 __sys_sendto+0x49b/0x510
 __x64_sys_sendto+0xe5/0x1c0
 do_syscall_64+0xc1/0x1d0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
[...]
Allocated by task 1:
 kasan_save_stack+0x33/0x60
 kasan_save_track+0x14/0x30
 __kasan_kmalloc+0x8f/0xa0
 copy_verifier_state+0xbc2/0xfb0
 do_check_common+0x2c51/0xc7e0
 bpf_check+0x5107/0x9960
 bpf_prog_load+0xf0e/0x2690
 __sys_bpf+0x1a61/0x49d0
 __x64_sys_bpf+0x7d/0xc0
 do_syscall_64+0xc1/0x1d0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 1:
 kasan_save_stack+0x33/0x60
 kasan_save_track+0x14/0x30
 kasan_save_free_info+0x3b/0x60
 poison_slab_object+0x109/0x170
 __kasan_slab_free+0x14/0x30
 kfree+0xca/0x2b0
 free_verifier_state+0xce/0x270
 do_check_common+0x4828/0xc7e0
 bpf_check+0x5107/0x9960
 bpf_prog_load+0xf0e/0x2690
 __sys_bpf+0x1a61/0x49d0
 __x64_sys_bpf+0x7d/0xc0
 do_syscall_64+0xc1/0x1d0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Comment 1 Mauro Matteo Cascella 2024-07-30 16:38:55 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024072953-CVE-2024-42073-3453@gregkh/T

Comment 2 Mauro Matteo Cascella 2024-07-30 16:39:14 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 2301708]