CVE-2024-57976

/// Technical description

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

btrfs: do proper folio cleanup when cow_file_range() failed

[BUG]

When testing with COW fixup marked as BUG_ON() (this is involved with the

new pin_user_pages*() change, which should not result new out-of-band

dirty pages), I hit a crash triggered by the BUG_ON() from hitting COW

fixup path.

This BUG_ON() happens just after a failed btrfs_run_delalloc_range():

BTRFS error (device dm-2): failed to run delalloc range, root 348 ino 405 folio 65536 submit_bitmap 6-15 start 90112 len 106496: -28

------------[ cut here ]------------

kernel BUG at fs/btrfs/extent_io.c:1444!

Internal error: Oops - BUG: 00000000f2000800 [#1] SMP

CPU: 0 UID: 0 PID: 434621 Comm: kworker/u24:8 Tainted: G OE 6.12.0-rc7-custom+ #86

Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022

Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs]

pc : extent_writepage_io+0x2d4/0x308 [btrfs]

lr : extent

/// 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