vulnerability

Amazon Linux AMI 2: CVE-2022-49021: Security patch for kernel (Multiple Advisories)

Severity
5
CVSS
(AV:L/AC:L/Au:S/C:N/I:N/A:C)
Published
Oct 21, 2024
Added
Mar 14, 2025
Modified
Mar 17, 2025

Description

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

net: phy: fix null-ptr-deref while probe() failed

I got a null-ptr-deref report as following when doing fault injection test:

BUG: kernel NULL pointer dereference, address: 0000000000000058
Oops: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 PID: 253 Comm: 507-spi-dm9051 Tainted: G B N 6.1.0-rc3+
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:klist_put+0x2d/0xd0
Call Trace:
<TASK>
klist_remove+0xf1/0x1c0
device_release_driver_internal+0x23e/0x2d0
bus_remove_device+0x1bd/0x240
device_del+0x357/0x770
phy_device_remove+0x11/0x30
mdiobus_unregister+0xa5/0x140
release_nodes+0x6a/0xa0
devres_release_all+0xf8/0x150
device_unbind_cleanup+0x19/0xd0

//probe path:
phy_device_register()
device_add()

phy_connect
phy_attach_direct() //set device driver
probe() //it's failed, driver is not bound
device_bind_driver() // probe failed, it's not called

//remove path:
phy_device_remove()
device_del()
device_release_driver_internal()
__device_release_driver() //dev->drv is not NULL
klist_remove() <- knode_driver is not added yet, cause null-ptr-deref

In phy_attach_direct(), after setting the 'dev->driver', probe() fails,
device_bind_driver() is not called, so the knode_driver->n_klist is not
set, then it causes null-ptr-deref in __device_release_driver() while
deleting device. Fix this by setting dev->driver to NULL in the error
path in phy_attach_direct().

Solutions

amazon-linux-ami-2-upgrade-bpftoolamazon-linux-ami-2-upgrade-bpftool-debuginfoamazon-linux-ami-2-upgrade-kernelamazon-linux-ami-2-upgrade-kernel-debuginfoamazon-linux-ami-2-upgrade-kernel-debuginfo-common-aarch64amazon-linux-ami-2-upgrade-kernel-debuginfo-common-x86_64amazon-linux-ami-2-upgrade-kernel-develamazon-linux-ami-2-upgrade-kernel-headersamazon-linux-ami-2-upgrade-kernel-livepatch-4-14-301-224-520amazon-linux-ami-2-upgrade-kernel-livepatch-5-10-162-141-675amazon-linux-ami-2-upgrade-kernel-livepatch-5-15-86-53-137amazon-linux-ami-2-upgrade-kernel-toolsamazon-linux-ami-2-upgrade-kernel-tools-debuginfoamazon-linux-ami-2-upgrade-kernel-tools-develamazon-linux-ami-2-upgrade-perfamazon-linux-ami-2-upgrade-perf-debuginfoamazon-linux-ami-2-upgrade-python-perfamazon-linux-ami-2-upgrade-python-perf-debuginfo
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