发布时间: 2024年12月8日
修改时间: 2025年1月4日
In the Linux kernel, the following vulnerability has been resolved: fsnotify: Fix ordering of iput() and watched_objects decrement Ensure the superblock is kept alive until we're done with iput(). Holding a reference to an inode is not allowed unless we ensure the superblock stays alive, which fsnotify does by keeping the watched_objects count elevated, so iput() must happen before the watched_objects decrement. This can lead to a UAF of something like sb->s_fs_info in tmpfs, but the UAF is hard to hit because race orderings that oops are more likely, thanks to the CHECK_DATA_CORRUPTION() block in generic_shutdown_super(). Also, ensure that fsnotify_put_sb_watched_objects() doesn't call fsnotify_sb_watched_objects() on a superblock that may have already been freed, which would cause a UAF read of sb->s_fsnotify_info.
| NVD | openEuler | |
|---|---|---|
| Confidentiality | High | Low |
| Attack Vector | Local | Local |
| CVSS评分 | 7.8 | 3.9 |
| Attack Complexity | Low | High |
| Privileges Required | Low | High |
| Scope | Unchanged | Unchanged |
| Integrity | High | Low |
| User Interaction | None | None |
| Availability | High | Low |
| 公告名 | 概要 | 发布时间 |
|---|---|---|
| KylinSec-SA-2024-4361 | In the Linux kernel, the following vulnerability has been resolved: fsnotify: Fix ordering of iput() and watched_objects decrement Ensure the superblock is kept alive until we're done with iput(). Holding a reference to an inode is not allowed unless we ensure the superblock stays alive, which fsnotify does by keeping the watched_objects count elevated, so iput() must happen before the watched_objects decrement. This can lead to a UAF of something like sb->s_fs_info in tmpfs, but the UAF is hard to hit because race orderings that oops are more likely, thanks to the CHECK_DATA_CORRUPTION() block in generic_shutdown_super(). Also, ensure that fsnotify_put_sb_watched_objects() doesn't call fsnotify_sb_watched_objects() on a superblock that may have already been freed, which would cause a UAF read of sb->s_fsnotify_info. | 2024年12月16日 |
| 产品 | 包 | 状态 |
|---|---|---|
| KY3.4-5 | kernel | Unaffected |
| KY3.5.2 | kernel | Unaffected |
| KY3.5.3 | kernel | Unaffected |
| V6 | kernel | Unaffected |
