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CVE-2026-98253

RDMA/ucma: Serialize join and leave on copy_to_user failure

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 5.10.271, 5.12, 5.15.222, 6.1.189, 6.6.158, and 3 more
None on Exploit-DB, Metasploit or GitHub

Summary

In the Linux kernel, the following vulnerability has been resolved: RDMA/ucma: Serialize join and leave on copy_to_user failure rdma_join_multicast() queues RoCE work that later reads the ucma_multicast through event->param.ud.private_data, then list_add()s the CMA multicast at the head of id_priv->mc_list. rdma_leave_multicast() matches only by sockaddr and destroys the first hit. ucma_process_join() used to drop ctx->mutex after a successful join and retake it only if copy_to_user() failed. Two concurrent JOIN_MCAST calls with the same address can therefore insert a second CMA entry before the first thread's leave. leave then cancels the newer work and the older worker still dereferences the ucma_multicast that the first thread frees. Keep ctx->mutex held from rdma_join_multicast() through copy_to_user() and, on -EFAULT, through rdma_leave_multicast() so leave cannot miss this join. Do not leave if join itself failed: that path never published this address on mc_list, and a leave-by-addr would destroy an earlier successful join.

Timeline

  1. CVE published
  2. Record last updated

Affected versions

  • Linux Linux

    From 60d613b39e8d0c9f3b526e9c96445422b4562d76 · fixed in 29b9ed83d8bfab5c6e11fcbf1aa836aa4ae26cb9; From fe454dc31e84f8c14cb8942fcb61666c9f40745b · fixed in 52172e11bd074ccaded21740ffeb67123f01dd00; From fe454dc31e84f8c14cb8942fcb61666c9f40745b · fixed in 01e29d0d78a8f66f221625720a04939eef5ec1f6; From fe454dc31e84f8c14cb8942fcb61666c9f40745b · fixed in ae805d204cf1f15b87d1bf3529b4c649f3519420; From fe454dc31e84f8c14cb8942fcb61666c9f40745b · fixed in 43c4e24bd10370fc976f6220518049ce71419399; From fe454dc31e84f8c14cb8942fcb61666c9f40745b · fixed in 01cbdb724c584d7772fd25af2e4dfdf8527ce0d5; From fe454dc31e84f8c14cb8942fcb61666c9f40745b · fixed in 83610ee5e498fa5bfcb80031d2b959baea276bf6; From fe454dc31e84f8c14cb8942fcb61666c9f40745b · fixed in 662ade4de9ff5eceb0820a9f8e9fac70ba6a815b; From 5.10.20 · fixed in 5.10.271; From 5.11.3 · fixed in 5.12

  • Linux Linux

    5.12

  • KernelLinux

    fixed in 5.10.271; From 5.11.0 · fixed in 5.15.222; From 5.12.0 · fixed in 6.1.189; From 5.16.0 · fixed in 6.6.158; From 6.2.0 · fixed in 6.12.112; From 6.7.0 · fixed in 6.18.54; From 6.13.0 · fixed in 7.2.8

References 8

git.kernel.org