Executive brief
A security vulnerability in the Linux kernel's Reliable Datagram Sockets (RDS) component could allow a local user to view sensitive information from the system's memory. This occurs because the system fails to clear temporary storage before sending network connection details to a user. An attacker could exploit this to obtain internal system addresses or other data that could be used to bypass security protections.
Technical details
A kernel stack information leak exists in net/rds/connection.c. The functions rds_for_each_conn_info() and rds_walk_conn_path_info() allocate a buffer on the stack and pass it to visitor functions (like rds_ib_conn_info_visitor) to be populated. If the visitor function only partially fills the structure—which occurs when an RDS connection is not in the RDS_CONN_UP state—uninitialized stack memory, including kernel pointers and alignment holes, is copied back to userspace via rds_info_copy(). A local unprivileged user can trigger this by opening an AF_RDS socket, setting the transport to InfiniBand (IB), and calling getsockopt with RDS_INFO_IB_CONNECTIONS. The fix involves explicitly zeroing the buffer with memset() before it is passed to any visitor function.
Affected products
- Linux Linux Kernel All versions prior to fixed releases in 4.19.y, 5.4.y, 5.10.y, 5.15.y, 6.1.y, 6.6.y, 6.8.y, and 6.9.y
Timeline
- 2026-04-18: other: Patch submitted by Michael Bommarito
- 2026-06-01: patched: Commits merged into stable branches
- 2026-06-24: disclosed: CVE published
References
- https://git.kernel.org/stable/c/0797b2e6901827694aa9c34c4c72118c8c97fba1
- https://git.kernel.org/stable/c/5e67cc262afb384e835c3327e9d954eeaedc6a87
- https://git.kernel.org/stable/c/81651e9d7dea1c048d2952f57632a042931d7b43
- https://git.kernel.org/stable/c/912ba2e5704fdb8bc5decda96dfc1a57838f0099
- https://git.kernel.org/stable/c/91ce1bb6e4194dc2321748f68145359dcf86e350
- https://git.kernel.org/stable/c/b6ba93a7b71ed443c9843eb12d27ed86f1e52694
- https://git.kernel.org/stable/c/c7cb9eed8215a790f052f49cdccf577720d2bb62