CVE-2022-48919

/// Technical description

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

cifs: fix double free race when mount fails in cifs_get_root()

When cifs_get_root() fails during cifs_smb3_do_mount() we call

deactivate_locked_super() which eventually will call delayed_free() which

will free the context.

In this situation we should not proceed to enter the out: section in

cifs_smb3_do_mount() and free the same resources a second time.

[Thu Feb 10 12:59:06 2022] BUG: KASAN: use-after-free in rcu_cblist_dequeue+0x32/0x60

[Thu Feb 10 12:59:06 2022] Read of size 8 at addr ffff888364f4d110 by task swapper/1/0

[Thu Feb 10 12:59:06 2022] CPU: 1 PID: 0 Comm: swapper/1 Tainted: G OE 5.17.0-rc3+ #4

[Thu Feb 10 12:59:06 2022] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.0 12/17/2019

[Thu Feb 10 12:59:06 2022] Call Trace:

[Thu Feb 10 12:59:06 2022] <IRQ>

[Thu Feb 10 12:59:06 2022] dump_stack_lvl+0x5d/0x78

[Thu Feb 10 12:59:06 2022] print_

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References