CVE-2021-47468

/// Technical description

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

isdn: mISDN: Fix sleeping function called from invalid context

The driver can call card->isac.release() function from an atomic

context.

Fix this by calling this function after releasing the lock.

The following log reveals it:

[ 44.168226 ] BUG: sleeping function called from invalid context at kernel/workqueue.c:3018

[ 44.168941 ] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 5475, name: modprobe

[ 44.169574 ] INFO: lockdep is turned off.

[ 44.169899 ] irq event stamp: 0

[ 44.170160 ] hardirqs last enabled at (0): [<0000000000000000>] 0x0

[ 44.170627 ] hardirqs last disabled at (0): [<ffffffff814209ed>] copy_process+0x132d/0x3e00

[ 44.171240 ] softirqs last enabled at (0): [<ffffffff81420a1a>] copy_process+0x135a/0x3e00

[ 44.171852 ] softirqs last disabled at (0): [<0000000000000000>] 0x0

[ 44.172318 ] Preemption disabled at:

[ 44.172320 ] [<ffffffffa009b0a9>] nj_release+0x69/0x500 [

/// 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