Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
ASoC: meson: Keep link pointers valid on realloc failure
meson_card_reallocate_links() grows the DAI link and private data arrays with two consecutive krealloc() calls and updates the owner pointers only after both calls have succeeded.
A successful krealloc() may move the data: it frees the old block and returns a new one. When that happens for the link array and the second krealloc() then fails, card->dai_link still points to the block that krealloc() already freed, and the error path frees the new block too. The probe error path then calls meson_card_clean_references(), which dereferences card->dai_link and kfree()s it again, resulting in a use-after-free and a double free.
Commit card->dai_link and card->num_links right after the first krealloc() succeeds, so the pointer always refers to a valid allocation that meson_card_clean_references() can walk and free. krealloc() with __GFP_ZERO zero-initializes the added entries, so walking them on the error path is safe. With both failure paths reduced to a plain return, drop the goto labels and the error message.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.4.0 (+7 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 12 | Planned | — |
| Debian 13 | Will Not Fix |
17 kernels
|