Theodore Tso

**Name of the Vulnerable Software and Affected Versions** Linux kernel (affected versions not specified) **Description** The issue arises when a block device is frozen before being claimed by a filesystem, and another process attempts to mount the frozen block device. This can cause a concurrent `fs bdev thaw()` call, leading to the mounter aborting the mounting process due to an elevated `bdev->bd fsfreeze count`. The `get bdev super()` function will return NULL in such cases. Technical details include the involvement of `dm suspend()` and `dm resume()` calls, which interact with `bdev freeze()` and `fs bdev thaw()` functions. Variables such as `bdev->bd fsfreeze count` play a crucial role in this process. **Recommendations** At the moment, there is no information about a newer version that contains a fix for this vulnerability.

**Name of the Vulnerable Software and Affected Versions** Linux kernel (affected versions not specified) **Description** The issue arises when the call to `ext4 map blocks()` fails due to a corrupted file system, causing `ext4 ext replay set iblocks()` to get stuck in an infinite loop. This can be reproduced by running generic/526 with a file system that has `inline data` and `fast commit` enabled. The system will repeatedly log an EXT4-fs warning to the console, indicating a block greater than the maximum in an inode. The stack trace shows the functions involved, including `ext4 block to path()`, `ext4 ind map blocks()`, `ext4 map blocks()`, and others. The root cause is likely that `fast commit` replay is corrupting file systems with `inline data`, and better error handling is needed in the `fast commit` replay code path. **Recommendations** At the moment, there is no information about a newer version that contains a fix for this vulnerability.

**Name of the Vulnerable Software and Affected Versions** Linux kernel versions prior to 4.3.3 **Description** The issue allows local users to gain privileges or cause a denial of service (use-after-free) by leveraging improper access to a certain error field in the ext4 journal stop function. **Recommendations** For versions prior to 4.3.3, update to version 4.3.3 or later to resolve the issue.

**Name of the Vulnerable Software and Affected Versions** Linux kernel versions prior to 3.7.3 **Description** The issue allows physically proximate attackers to cause a denial of service (system hang) via a crafted filesystem on removable media. This is due to the ext4 orphan del function in fs/ext4/namei.c not properly handling orphan-list entries for non-journal filesystems. Multiple vulnerabilities in the Linux package of the Debian GNU/Linux operating system can be exploited by a local attacker, potentially leading to breaches of confidentiality, integrity, and availability of protected information. **Recommendations** For Linux kernel versions prior to 3.7.3, update to version 3.7.3 or later to resolve the issue. At the moment, there is no information about additional mitigation measures for other affected versions.