From d10e2a08799e858d3e71ea4169bcd018f216d444 Mon Sep 17 00:00:00 2001 From: Gang Yan Date: Fri, 14 Aug 2026 17:37:40 +0800 Subject: [PATCH] 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. Fixes: 8700e3e7c485 ("Soft RoCE driver") Signed-off-by: Gang Yan Link: https://patch.msgid.link/20260814093740.292954-1-gang.yan@linux.dev Reviewed-by: Zhu Yanjun Reviewed-by: Shukai Ni Tested-by: Shukai Ni Signed-off-by: Leon Romanovsky --- drivers/infiniband/sw/rxe/rxe_mr.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/sw/rxe/rxe_mr.c b/drivers/infiniband/sw/rxe/rxe_mr.c index 875eceb55fdf..71d9ea477289 100644 --- a/drivers/infiniband/sw/rxe/rxe_mr.c +++ b/drivers/infiniband/sw/rxe/rxe_mr.c @@ -33,7 +33,8 @@ int mr_check_range(struct rxe_mr *mr, u64 iova, size_t length) case IB_MR_TYPE_USER: case IB_MR_TYPE_MEM_REG: if (iova < mr->ibmr.iova || - iova + length > mr->ibmr.iova + mr->ibmr.length) { + length > mr->ibmr.length || + iova - mr->ibmr.iova > mr->ibmr.length - length) { rxe_dbg_mr(mr, "iova/length out of range\n"); return -EINVAL; }