Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
hfsplus: validate thread record before delete key rebuild
hfsplus_delete_cat() is called with str == NULL when the last open reference to an unlinked HFS+ hardlink backing inode is closed. In that case, the function finds the catalog thread by CNID and rebuilds the catalog key from thread.nodeName.
That reconstruction path reads thread.nodeName.length directly from the catalog B-tree into fd.search_key and then copies length * 2 bytes into fd.search_key->cat.name.unicode. It does not first check that the found record is a thread record or that its size matches the thread name.
A corrupted image can therefore provide an oversized thread name length and make hfs_bnode_read() write past the catalog search-key allocation.
Read the CNID record through hfsplus_brec_read_cat(), which bounds the record read to sizeof(hfsplus_cat_entry) and verifies that a thread record’s size exactly matches nodeName.length. Together, these checks ensure an accepted thread name fits HFSPLUS_MAX_STRLEN. Reject non-thread records before building the delete key from the validated thread name.
Share the thread-record-type helper between hfsplus_find_cat() and hfsplus_delete_cat().
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 6 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 7 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 6 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.4.0 (+19 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 12 | Planned | — |
| Debian 13 | In Rollout |
17 kernels
|