RDMA/core: Fix potential use after free in ib_free_cq()

Summary

In the Linux kernel, the following vulnerability has been resolved: RDMA/core: Fix potential use after free in ib_free_cq() When accessing a CQ via the netlink path the only synchronization mechanism for the said CQ is rdma_restrack_get(). Currently, rdma_restrack_del() is invoked at the end of ib_free_cq(), which is too late, since by that point vendor-specific resources associated with the CQ might already be freed. This can leave a short window where the CQ remains accessible through restrack, leading to a potential use-after-free. Fix this by moving the rdma_restrack_del() call to be before the freeing of the vendor-specific resources ensuring that the CQ is removed from restrack before its internal resources are released. This guarantees that no new users hold references to a CQ that is in the process of destruction.

Timeline

1. Sep 17, 2026, 4:10 PM UTCCVE published
2. Oct 19, 2026, 9:04 AM UTCRecord last updated

Affected versions

• Linux Linux

  From 43d781b9fa562f0c6e50f62c870fbfeb9dc85213 · fixed in a804b162f9bc2b38b2ed1b4752eea9faadb1645b; From 43d781b9fa562f0c6e50f62c870fbfeb9dc85213 · fixed in 91f8a17a22ab615a03743120e19935e731f28fb9; From 43d781b9fa562f0c6e50f62c870fbfeb9dc85213 · fixed in 76f2cb4f721815c3b6262a6dc2151de88646924c; From 43d781b9fa562f0c6e50f62c870fbfeb9dc85213 · fixed in b8dcca427096fc9c50f1b376847fea72bc842d31; From 43d781b9fa562f0c6e50f62c870fbfeb9dc85213 · fixed in 9abea37942534eeb049335476178696b654b000c; From 43d781b9fa562f0c6e50f62c870fbfeb9dc85213 · fixed in 43403fe45379c64fa6276e5a8ede44493e5d2d3d; From 43d781b9fa562f0c6e50f62c870fbfeb9dc85213 · fixed in 29dc2f8e1c97372c2871a70088707933515fbd5b; From 5.8.17 · fixed in 5.9; From 5.9.2 · fixed in 5.10

• Linux Linux

  5.10

• KernelLinux

  From 5.10.0 · fixed in 5.15.221; From 5.16.0 · fixed in 6.1.188; From 6.2.0 · fixed in 6.6.157; From 6.7.0 · fixed in 6.12.110; From 6.13.0 · fixed in 6.18.52; From 6.19.0 · fixed in 7.2.6

References 7