CVE-2022-48751 net/smc: Transitional solution for clcsock race issue
A race condition in the Linux kernel SMC module causes a null pointer dereference, leading to a system crash.
- 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-2022-48751?
CVE-2022-48751 is a high-severity vulnerability in Linux kernel, published on 20 Jun 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:
net/smc: Transitional solution for clcsock race issue
We encountered a crash in smc_setsockopt() and it is caused by accessing smc->clcsock after clcsock was released.
BUG: kernel NULL pointer dereference, address: 0000000000000020 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 1 PID: 50309 Comm: nginx Kdump: loaded Tainted: G E 5.16.0-rc4+ #53 RIP: 0010:smc_setsockopt+0x59/0x280 [smc] Call Trace: <TASK> __sys_setsockopt+0xfc/0x190 __x64_sys_setsockopt+0x20/0x30 do_syscall_64+0x34/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f16ba83918e </TASK>
This patch tries to fix it by holding clcsock_release_lock and checking whether clcsock has already been released before access.
In case that a crash of the same reason happens in smc_getsockopt() or smc_switch_to_fallback(), this patch also checkes smc->clcsock in them too. And the caller of smc_switch_to_fallback() will identify whether fallback succeeds according to the return value.
Weakness: CWE-476
Which versions are affected by CVE-2022-48751?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-48751?
Apply the vendor's patch.
Is CVE-2022-48751 being exploited?
There is no known exploitation of CVE-2022-48751 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-48751, GHSA-j385-2ppr-7766, ROOT-OS-DEBIAN-11-CVE-2022-48751, UBUNTU-CVE-2022-48751.