CVE-2023-52444

About vulnerability

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

f2fs: fix to avoid dirent corruption

As Al reported in link[1]:

f2fs_rename() … if (old_dir != new_dir && !whiteout) f2fs_set_link(old_inode, old_dir_entry, old_dir_page, new_dir); else f2fs_put_page(old_dir_page, 0);

You want correct inumber in the “..” link. And cross-directory rename does move the source to new parent, even if you’d been asked to leave a whiteout in the old place.

[1] https://lore.kernel.org/all/20231017055040.GN800259@ZenIV/

With below testcase, it may cause dirent corruption, due to it missed to call f2fs_set_link() to update “..” link to new directory.

• mkdir -p dir/foo
• renameat2 -w dir/foo bar

[ASSERT] (__chk_dots_dentries:1421) –> Bad inode number[0x4] for ‘..’, parent parent ino is [0x3] [FSCK] other corrupted bugs [Fail]

Affected product:

AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Debian 10 ELS , Oracle Linux 7 ELS , TuxCare 9.6 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS

Affected packages:

linux @ 4.15.0 (+12 more)

Live-patch status from KernelCare for each operating system.