Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
fs/adfs: validate nzones in adfs_validate_bblk()
Reject ADFS disc records with a zero zone count during boot block validation, before the disc record is used.
When nzones is 0, adfs_read_map() passes it to kmalloc_array(0, …) which returns ZERO_SIZE_PTR, and adfs_map_layout() then writes to dm[-1], causing an out-of-bounds write before the allocated buffer.
adfs_validate_dr0() already rejects nzones != 1 for old-format images. Add the equivalent check to adfs_validate_bblk() for new-format images so that a crafted image with nzones == 0 is rejected at probe time.
Found by syzkaller.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , TuxCare 9.6 ESU , Ubuntu 20.04 ELS
- Affected packages:
- kernel @ 5.14.0 (+3 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 11 | In Rollout |
37 kernels
|
| Debian 11 cloud | In Rollout |
17 kernels
|
| Debian 12 | Planned | — |
| Ubuntu 22.04 | Planned | — |
| Ubuntu 24.04 | Planned | — |