RDMA/rxe: Fix integer overflow in mr_check_range() leading to OOB access

Summary

In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Fix integer overflow in mr_check_range() leading to OOB access mr_check_range() validates that [iova, iova+length) falls within the registered MR range using wraparound-prone arithmetic: if (iova < mr->ibmr.iova || iova + length > mr->ibmr.iova + mr->ibmr.length) A remote peer can craft an RDMA-Write/Read RETH so that iova + length wraps to 0 (e.g. iova=0xfffffffffffffff8, length=8), bypassing the check. rxe_mr_iova_to_index() then computes a huge index (int idx, only guarded by WARN_ON) and rxe_mr_copy_xarray() dereferences mr->page_info[huge], causing an out-of-bounds read/write and a kernel oops that is triggerable by an unauthenticated remote peer. Rewrite the check in overflow-safe form; the first two clauses guarantee that the subsequent subtractions do not underflow: if (iova < mr->ibmr.iova || length > mr->ibmr.length || iova - mr->ibmr.iova > mr->ibmr.length - length) With the fix, mr_check_range() returns -EINVAL for the crafted iova and the responder reports REMOTE_ACCESS_ERROR instead of triggering the OOB.

Affected versions

• Linux Linux

  From 8700e3e7c4857d28ebaa824509934556da0b3e76 · fixed in b7d2118660545a00b21e83010ded1a231c6fb8c5; From 8700e3e7c4857d28ebaa824509934556da0b3e76 · fixed in 5d9426a74fc8cb8f375fcdc19b465a030f9b8cab; From 8700e3e7c4857d28ebaa824509934556da0b3e76 · fixed in 2f3b705144e3a3c14184fec6e354680081fe91ec; From 8700e3e7c4857d28ebaa824509934556da0b3e76 · fixed in 3431f525718f6b07da308cda6d44f8cb548bbd37; From 8700e3e7c4857d28ebaa824509934556da0b3e76 · fixed in d10e2a08799e858d3e71ea4169bcd018f216d444

• Linux Linux

  4.8

• KernelLinux

  From 4.8.0 · fixed in 6.6.158; From 6.7.0 · fixed in 6.12.112; From 6.13.0 · fixed in 6.18.54; From 6.19.0 · fixed in 7.2.8

References 5