title: f2fs: fix to avoid dirent corruption
description: 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: Linux
vendor: Linux
defaultStatus: unaffected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 7e01e7ad746b, lessThan: 02160112e6d4, status: affected, versionType: git
version: 7e01e7ad746b, lessThan: 5624a3c1b1eb, status: affected, versionType: git
version: 7e01e7ad746b, lessThan: 6f866885e147, status: affected, versionType: git
version: 7e01e7ad746b, lessThan: f100ba617d8b, status: affected, versionType: git
version: 7e01e7ad746b, lessThan: f0145860c20b, status: affected, versionType: git
version: 7e01e7ad746b, lessThan: d3c0b49aaa12, status: affected, versionType: git
version: 7e01e7ad746b, lessThan: 2fb4867f4405, status: affected, versionType: git
version: 7e01e7ad746b, lessThan: 53edb549565f, status: affected, versionType: git
}
{
product: Linux
vendor: Linux
defaultStatus: affected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 4.2, status: affected
version: 0, lessThan: 4.2, status: unaffected, versionType: custom
version: 4.19.306, lessThanOrEqual: 4.19.*, status: unaffected, versionType: custom
version: 5.4.268, lessThanOrEqual: 5.4.*, status: unaffected, versionType: custom
version: 5.10.209, lessThanOrEqual: 5.10.*, status: unaffected, versionType: custom
version: 5.15.148, lessThanOrEqual: 5.15.*, status: unaffected, versionType: custom
version: 6.1.75, lessThanOrEqual: 6.1.*, status: unaffected, versionType: custom
version: 6.6.14, lessThanOrEqual: 6.6.*, status: unaffected, versionType: custom
version: 6.7.2, lessThanOrEqual: 6.7.*, status: unaffected, versionType: custom
version: 6.8, lessThanOrEqual: *, status: unaffected, versionType: original_commit_for_fix
}
