Vulnerabilities > CVE-2024-50006 - Improper Locking vulnerability in Linux Kernel
Summary
In the Linux kernel, the following vulnerability has been resolved: ext4: fix i_data_sem unlock order in ext4_ind_migrate() Fuzzing reports a possible deadlock in jbd2_log_wait_commit. This issue is triggered when an EXT4_IOC_MIGRATE ioctl is set to require synchronous updates because the file descriptor is opened with O_SYNC. This can lead to the jbd2_journal_stop() function calling jbd2_might_wait_for_commit(), potentially causing a deadlock if the EXT4_IOC_MIGRATE call races with a write(2) system call. This problem only arises when CONFIG_PROVE_LOCKING is enabled. In this case, the jbd2_might_wait_for_commit macro locks jbd2_handle in the jbd2_journal_stop function while i_data_sem is locked. This triggers lockdep because the jbd2_journal_start function might also lock the same jbd2_handle simultaneously. Found by Linux Verification Center (linuxtesting.org) with syzkaller. Rule: add
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Leveraging Race Conditions This attack targets a race condition occurring when multiple processes access and manipulate the same resource concurrently and the outcome of the execution depends on the particular order in which the access takes place. The attacker can leverage a race condition by "running the race", modifying the resource and modifying the normal execution flow. For instance a race condition can occur while accessing a file, the attacker can trick the system by replacing the original file with his version and cause the system to read the malicious file.
- Leveraging Race Conditions via Symbolic Links This attack leverages the use of symbolic links (Symlinks) in order to write to sensitive files. An attacker can create a Symlink link to a target file not otherwise accessible to her. When the privileged program tries to create a temporary file with the same name as the Symlink link, it will actually write to the target file pointed to by the attackers' Symlink link. If the attacker can insert malicious content in the temporary file she will be writing to the sensitive file by using the Symlink. The race occurs because the system checks if the temporary file exists, then creates the file. The attacker would typically create the Symlink during the interval between the check and the creation of the temporary file.
References
- https://git.kernel.org/stable/c/53b1999cfd2c7addf2e581a32865fe8835467b44
- https://git.kernel.org/stable/c/ef05572da0c0eb89614ed01cc17d3c882bdbd1ff
- https://git.kernel.org/stable/c/9fedf51ab8cf7b69bff08f37fe0989fec7f5d870
- https://git.kernel.org/stable/c/d43776b907659affef1de888525847d64b244194
- https://git.kernel.org/stable/c/6252cb6bde7fc76cb8dcb49d1def7c326b190820
- https://git.kernel.org/stable/c/d58a00e981d3118b91d503da263e640b7cde6729
- https://git.kernel.org/stable/c/cc749e61c011c255d81b192a822db650c68b313f