AZL-55195
See a problem?- Import Source
- https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-55195.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/AZL-55195
- Upstream
- Published
- 2024-12-27T14:15:34Z
- Modified
- 2026-09-03T05:27:10Z
- Severity
-
- 5.5 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
- Summary
- CVE-2024-56549 affecting package kernel for versions less than 6.6.78.1-1
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
cachefiles: Fix NULL pointer dereference in object->file
At present, the object->file has the NULL pointer dereference problem in ondemand-mode. The root cause is that the allocated fd and object->file lifetime are inconsistent, and the user-space invocation to anon_fd uses object->file. Following is the process that triggers the issue:
[write fd] [umount]cachefiles_ondemand_fd_write_iter fscache_cookie_state_machine cachefiles_withdraw_cookie if (!file) return -ENOBUFS cachefiles_clean_up_object cachefiles_unmark_inode_in_use fput(object->file) object->file = NULL // file NULL pointer dereference! __cachefiles_write(..., file, ...)
Fix this issue by add an additional reference count to the object->file before write/llseek, and decrement after it finished.
- References