CVE-2022-50730
Description
From CVE.org
In the Linux kernel, the following vulnerability has been resolved: ext4: silence the warning when evicting inode with dioread_nolock When evicting an inode with default dioread_nolock, it could be raced by the unwritten extents converting kworker after writeback some new allocated dirty blocks. It convert unwritten extents to written, the extents could be merged to upper level and free extent blocks, so it could mark the inode dirty again even this inode has been marked I_FREEING. But the inode->i_io_list check and warning in ext4_evict_inode() missing this corner case. Fortunately, ext4_evict_inode() will wait all extents converting finished before this check, so it will not lead to inode use-after-free problem, every thing is OK besides this warning. The WARN_ON_ONCE was originally designed for finding inode use-after-free issues in advance, but if we add current dioread_nolock case in, it will become not quite useful, so fix this warning by just remove this check. ====== WARNING: CPU: 7 PID: 1092 at fs/ext4/inode.c:227 ext4_evict_inode+0x875/0xc60 ... RIP: 0010:ext4_evict_inode+0x875/0xc60 ... Call Trace: <TASK> evict+0x11c/0x2b0 iput+0x236/0x3a0 do_unlinkat+0x1b4/0x490 __x64_sys_unlinkat+0x4c/0xb0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7fa933c1115b ====== rm kworker ext4_end_io_end() vfs_unlink() ext4_unlink() ext4_convert_unwritten_io_end_vec() ext4_convert_unwritten_extents() ext4_map_blocks() ext4_ext_map_blocks() ext4_ext_try_to_merge_up() __mark_inode_dirty() check !I_FREEING locked_inode_to_wb_and_lock_list() iput() iput_final() evict() ext4_evict_inode() truncate_inode_pages_final() //wait release io_end inode_io_list_move_locked() ext4_release_io_end() trigger WARN_ON_ONCE()
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 3.3 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | Low | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Understanding the Weakness (CWE)
Integrity,Other
Technical Impact: Alter Execution Logic; Unexpected State
The attacker can gain access to otherwise unauthorized resources.
Integrity,Other
Technical Impact: Modify Application Data; Modify Files or Directories; Modify Memory; Other
Race conditions such as this kind may be employed to gain read or write access to resources which are not normally readable or writable by the user in question.
Integrity,Other
Technical Impact: Other
The resource in question, or other resources (through the corrupted one), may be changed in undesirable ways by a malicious user.
Non-Repudiation
Technical Impact: Hide Activities
If a file or other resource is written in this method, as opposed to in a valid way, logging of the activity may not occur.
Non-Repudiation,Other
Technical Impact: Other
In some cases it may be possible to delete files a malicious user might not otherwise have access to, such as log files.
Other
Technical Impact: Unexpected State
The product may perform invalid actions when the resource is in an unexpected state.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
