CVE-2024-35902 net/rds: fix possible cp null dereference
A null pointer dereference in the Linux kernel's RDS module can cause a system crash, requiring a kernel patch to prevent denial of service.
- 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-2024-35902?
CVE-2024-35902 is a medium-severity vulnerability in Debian Debian Linux, published on 19 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:
net/rds: fix possible cp null dereference
cp might be null, calling cp->cp_conn would produce null dereference
[Simon Horman adds:]
Analysis:
* cp is a parameter of __rds_rdma_map and is not reassigned.
* The following call-sites pass a NULL cp argument to __rds_rdma_map()
- rds_get_mr() - rds_get_mr_for_dest
* Prior to the code above, the following assumes that cp may be NULL (which is indicative, but could itself be unnecessary)
trans_private = rs->rs_transport->get_mr( sg, nents, rs, &mr->r_key, cp ? cp->cp_conn : NULL, args->vec.addr, args->vec.bytes, need_odp ? ODP_ZEROBASED : ODP_NOT_NEEDED);
* The code modified by this patch is guarded by IS_ERR(trans_private), where trans_private is assigned as per the previous point in this analysis.
The only implementation of get_mr that I could locate is rds_ib_get_mr() which can return an ERR_PTR if the conn (4th) argument is NULL.
* ret is set to PTR_ERR(trans_private). rds_ib_get_mr can return ERR_PTR(-ENODEV) if the conn (4th) argument is NULL. Thus ret may be -ENODEV in which case the code in question will execute.
Conclusion: * cp may be NULL at the point where this patch adds a check; this patch does seem to address a possible bug
Weakness: CWE-476
Which versions are affected by CVE-2024-35902?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2024-35902?
Apply the vendor's patch.
Is CVE-2024-35902 being exploited?
There is no known exploitation of CVE-2024-35902 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as BELL-CVE-2024-35902, DEBIAN-CVE-2024-35902, GHSA-hpp4-8vc7-9fh4, UBUNTU-CVE-2024-35902.