Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
zram: fix use-after-free in zram_bvec_write_partial()
zram_read_page() picks the sync or async backing device read path based on whether the parent bio is NULL. zram_bvec_write_partial() passes its parent bio down, so for ZRAM_WB slots the read is dispatched asynchronously and zram_read_page() returns 0 while the bio is still in flight. The caller then runs memcpy_from_bvec(), zram_write_page() and __free_page() on the buffer, leaving the async read to write into a freed page.
zram_bvec_read_partial() was switched to NULL in commit 4e3c87b9421d (“zram: fix synchronous reads”) for the same reason; the write_partial counterpart was missed.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 7 ELS , TuxCare 9.6 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux-hwe @ 4.15.0 (+11 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| AlmaLinux 10 | In Rollout |
61 kernels
|
| AlmaLinux 9 | Will Not Fix |
127 kernels
|
| Debian 13 | Released |
10 kernels
|
| Oracle Linux 10 | In Rollout |
47 kernels
|
| Oracle Linux 9 | Will Not Fix |
126 kernels
|
| RHEL 10 | In Rollout |
61 kernels
|
| RHEL 8 | Planned | — |
| RHEL 9 | Will Not Fix |
125 kernels
|
| Rocky Linux 10 | In Rollout |
44 kernels
|
| Rocky Linux 9 | Will Not Fix |
102 kernels
|