CVE-2021-47456 Affecting kernel-rt-kvm package, versions *

Note: Versions mentioned in the description apply only to the upstream kernel-rt-kvm package and not the kernel-rt-kvm package as distributed by Centos. See How to fix? for Centos:7 relevant fixed versions and status.

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

can: peak_pci: peak_pci_remove(): fix UAF

When remove the module peek_pci, referencing 'chan' again after releasing 'dev' will cause UAF.

Fix this by releasing 'dev' later.

The following log reveals it:

[ 35.961814 ] BUG: KASAN: use-after-free in peak_pci_remove+0x16f/0x270 [peak_pci] [ 35.963414 ] Read of size 8 at addr ffff888136998ee8 by task modprobe/5537 [ 35.965513 ] Call Trace: [ 35.965718 ] dump_stack_lvl+0xa8/0xd1 [ 35.966028 ] print_address_description+0x87/0x3b0 [ 35.966420 ] kasan_report+0x172/0x1c0 [ 35.966725 ] ? peak_pci_remove+0x16f/0x270 [peak_pci] [ 35.967137 ] ? trace_irq_enable_rcuidle+0x10/0x170 [ 35.967529 ] ? peak_pci_remove+0x16f/0x270 [peak_pci] [ 35.967945 ] __asan_report_load8_noabort+0x14/0x20 [ 35.968346 ] peak_pci_remove+0x16f/0x270 [peak_pci] [ 35.968752 ] pci_device_remove+0xa9/0x250

• https://access.redhat.com/security/cve/CVE-2021-47456
• https://git.kernel.org/stable/c/0e5afdc2315b0737edcf55bede4ee1640d2d464d
• https://git.kernel.org/stable/c/1248582e47a9f7ce0ecd156c39fc61f8b6aa3699
• https://git.kernel.org/stable/c/1c616528ba4aeb1125a06b407572ab7b56acae38
• https://git.kernel.org/stable/c/28f28e4bc3a5e0051faa963f10b778ab38c1db69
• https://git.kernel.org/stable/c/34914971bb3244db4ce2be44e9438a9b30c56250
• https://git.kernel.org/stable/c/447d44cd2f67a20b596ede3ca3cd67086dfd9ca9
• https://git.kernel.org/stable/c/949fe9b35570361bc6ee2652f89a0561b26eec98
• https://git.kernel.org/stable/c/adbda14730aacce41c0d3596415aa39ad63eafd9