CVE-2024-42304

In the Linux kernel, the following vulnerability has been resolved: ext4: make sure the first directory block is not a hole The syzbot constructs a directory that has no dirblock but is non-inline, i.e. the first directory block is a hole. And no errors are reported when creating files in this directory in the following flow. ext4_mknod ... ext4_add_entry // Read block 0 ext4_read_dirblock(dir, block, DIRENT) bh = ext4_bread(NULL, inode, block, 0) if (!bh && (type == INDEX || type == DIRENT_HTREE)) // The first directory block is a hole // But type == DIRENT, so no error is reported. After that, we get a directory block without '.' and '..' but with a valid dentry. This may cause some code that relies on dot or dotdot (such as make_indexed_dir()) to crash. Therefore when ext4_read_dirblock() finds that the first directory block is a hole report that the filesystem is corrupted and return an error to avoid loading corrupted data from disk causing something bad.

• linux linux kernel (>= 4.9.187 < 4.10) • linux linux kernel (>= 4.14.135 < 4.15) • linux linux kernel (>= 4.19.62 < 4.19.320) • linux linux kernel (>= 5.1.21 < 5.2) • linux linux kernel (>= 5.2.4 < 5.4.282) • linux linux kernel (>= 5.5 < 5.10.224) • linux linux kernel (>= 5.11 < 5.15.165) • linux linux kernel (>= 5.16 < 6.1.103) • linux linux kernel (>= 6.2 < 6.6.44) • linux linux kernel (>= 6.7 < 6.10.3)