CVE-2024-36925 swiotlb: initialise restricted pool list_head when SWIOTLB_DYNAMIC=y
A null pointer dereference in the Linux kernel causes a crash when using restricted DMA pools with dynamic SWIOTLB enabled.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-36925?
CVE-2024-36925 is a medium-severity vulnerability in Linux kernel, published on 30 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
swiotlb: initialise restricted pool list_head when SWIOTLB_DYNAMIC=y
Using restricted DMA pools (CONFIG_DMA_RESTRICTED_POOL=y) in conjunction with dynamic SWIOTLB (CONFIG_SWIOTLB_DYNAMIC=y) leads to the following crash when initialising the restricted pools at boot-time:
| Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 | Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP | pc : rmem_swiotlb_device_init+0xfc/0x1ec | lr : rmem_swiotlb_device_init+0xf0/0x1ec | Call trace: | rmem_swiotlb_device_init+0xfc/0x1ec | of_reserved_mem_device_init_by_idx+0x18c/0x238 | of_dma_configure_id+0x31c/0x33c | platform_dma_configure+0x34/0x80
faddr2line reveals that the crash is in the list validation code:
include/linux/list.h:83 include/linux/rculist.h:79 include/linux/rculist.h:106 kernel/dma/swiotlb.c:306 kernel/dma/swiotlb.c:1695
because add_mem_pool() is trying to list_add_rcu() to a NULL 'mem->pools'.
Fix the crash by initialising the 'mem->pools' list_head in rmem_swiotlb_device_init() before calling add_mem_pool().
Weakness: CWE-476
Which versions are affected by CVE-2024-36925?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-36925?
Apply the vendor's patch.
Is CVE-2024-36925 being exploited?
There is no known exploitation of CVE-2024-36925 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-42462, BELL-CVE-2024-36925, DEBIAN-CVE-2024-36925, UBUNTU-CVE-2024-36925.