CVE-2024-42273

/// Technical description

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

f2fs: assign CURSEG_ALL_DATA_ATGC if blkaddr is valid

mkdir /mnt/test/comp

f2fs_io setflags compression /mnt/test/comp

dd if=/dev/zero of=/mnt/test/comp/testfile bs=16k count=1

truncate --size 13 /mnt/test/comp/testfile

In the above scenario, we can get a BUG_ON.

kernel BUG at fs/f2fs/segment.c:3589!

Call Trace:

do_write_page+0x78/0x390 [f2fs]

f2fs_outplace_write_data+0x62/0xb0 [f2fs]

f2fs_do_write_data_page+0x275/0x740 [f2fs]

f2fs_write_single_data_page+0x1dc/0x8f0 [f2fs]

f2fs_write_multi_pages+0x1e5/0xae0 [f2fs]

f2fs_write_cache_pages+0xab1/0xc60 [f2fs]

f2fs_write_data_pages+0x2d8/0x330 [f2fs]

do_writepages+0xcf/0x270

__writeback_single_inode+0x44/0x350

writeback_sb_inodes+0x242/0x530

__writeback_inodes_wb+0x54/0xf0

wb_writeback+0x192/0x310

wb_workfn+0x30d/0x400

The reason is we gave CURSEG_ALL_DATA_ATGC to COMPR_ADDR where the

page was set the gcing flag by set_cluster_dirty().

/// 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