CVE-2024-41083

/// Technical description

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

netfs: Fix netfs_page_mkwrite() to check folio->mapping is valid

Fix netfs_page_mkwrite() to check that folio->mapping is valid once it has

taken the folio lock (as filemap_page_mkwrite() does). Without this,

generic/247 occasionally oopses with something like the following:

BUG: kernel NULL pointer dereference, address: 0000000000000000

#PF: supervisor read access in kernel mode

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

RIP: 0010:trace_event_raw_event_netfs_folio+0x61/0xc0

...

Call Trace:

<TASK>

? __die_body+0x1a/0x60

? page_fault_oops+0x6e/0xa0

? exc_page_fault+0xc2/0xe0

? asm_exc_page_fault+0x22/0x30

? trace_event_raw_event_netfs_folio+0x61/0xc0

trace_netfs_folio+0x39/0x40

netfs_page_mkwrite+0x14c/0x1d0

do_page_mkwrite+0x50/0x90

do_pte_missing+0x184/0x200

__handle_mm_fault+0x42d/0x500

handle_mm_fault+0x121/0x1f0

do_user_ad

/// 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