CVE-2024-45000

/// Technical description

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

fs/netfs/fscache_cookie: add missing "n_accesses" check

This fixes a NULL pointer dereference bug due to a data race which

looks like this:

BUG: kernel NULL pointer dereference, address: 0000000000000008

#PF: supervisor read access in kernel mode

#PF: error_code(0x0000) - not-present page

PGD 0 P4D 0

Oops: 0000 [#1] SMP PTI

CPU: 33 PID: 16573 Comm: kworker/u97:799 Not tainted 6.8.7-cm4all1-hp+ #43

Hardware name: HP ProLiant DL380 Gen9/ProLiant DL380 Gen9, BIOS P89 10/17/2018

Workqueue: events_unbound netfs_rreq_write_to_cache_work

RIP: 0010:cachefiles_prepare_write+0x30/0xa0

Code: 57 41 56 45 89 ce 41 55 49 89 cd 41 54 49 89 d4 55 53 48 89 fb 48 83 ec 08 48 8b 47 08 48 83 7f 10 00 48 89 34 24 48 8b 68 20 <48> 8b 45 08 4c 8b 38 74 45 49 8b 7f 50 e8 4e a9 b0 ff 48 8b 73 10

RSP: 0018:ffffb4e78113bde0 EFLAGS: 00010286

RAX: ffff976126be6d10 RBX: ffff97615cdb8438 RCX: 0000000000020000

RDX: ffff97

/// 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