From 1039bffd6ae9c75b42b7d148d6c1106134107b66 Mon Sep 17 00:00:00 2001 From: Xie Yuanbin Date: Tue, 28 Jul 2026 03:16:42 +0100 Subject: ARM: 9485/1: mm: acquire mmap write lock around show_pte() for user faults When CONFIG_DEBUG_USER=y, and cmdline "user_debug=31" is set, a user fault may trigger show_pte() without any lock. If another thread in the same process concurrently calls munmap(), the page table pages may be freed while show_pte() is still traversing them, causing a use-after-free in show_pte(). If CONFIG_ARM_LPAE=y, this may cause a kernel panic if the pages table of PMD are freed when show_pte() is running. Acquire mmap_write_lock() around show_pte() for user faults to fix the contention. For user faults, additionally restrict that show_pte() is called only when the addr is a user-space address (addr < TASK_SIZE). This is because the lock of tsk->mm only protects the virtual memory of user address space, furthermore, dumping the page tables of a kernel-space address for user faults is unnecessary and may have security implications. Keep everything unchanged for kernel faults, because the kernel is already in the "oops" state, acquiring a lock may risk a deadlock. Co-developed-by: Qi Xi Fixes: 6d021b724481 ("ARM: dump pgd, pmd and pte states on unhandled data abort faults") Link: https://lore.kernel.org/20260716014022.2823-1-xieyuanbin1@huawei.com Acked-by: Lorenzo Stoakes (ARM) Reviewed-by: Linus Walleij Signed-off-by: Qi Xi Signed-off-by: Xie Yuanbin Signed-off-by: Russell King --- include/uapi/rdma/ionic-abi.h | 115 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 115 insertions(+) create mode 100644 include/uapi/rdma/ionic-abi.h (limited to 'include/uapi/rdma/ionic-abi.h') diff --git a/include/uapi/rdma/ionic-abi.h b/include/uapi/rdma/ionic-abi.h new file mode 100644 index 000000000..7b589d3e9 --- /dev/null +++ b/include/uapi/rdma/ionic-abi.h @@ -0,0 +1,115 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +/* Copyright (C) 2018-2025, Advanced Micro Devices, Inc */ + +#ifndef IONIC_ABI_H +#define IONIC_ABI_H + +#include + +#define IONIC_ABI_VERSION 1 + +#define IONIC_EXPDB_64 1 +#define IONIC_EXPDB_128 2 +#define IONIC_EXPDB_256 4 +#define IONIC_EXPDB_512 8 + +#define IONIC_EXPDB_SQ 1 +#define IONIC_EXPDB_RQ 2 + +#define IONIC_CMB_ENABLE 1 +#define IONIC_CMB_REQUIRE 2 +#define IONIC_CMB_EXPDB 4 +#define IONIC_CMB_WC 8 +#define IONIC_CMB_UC 16 + +struct ionic_ctx_req { + __u32 rsvd[2]; +}; + +struct ionic_ctx_resp { + __u32 rsvd; + __u32 page_shift; + + __aligned_u64 dbell_offset; + + __u16 version; + __u8 qp_opcodes; + __u8 admin_opcodes; + + __u8 sq_qtype; + __u8 rq_qtype; + __u8 cq_qtype; + __u8 admin_qtype; + + __u8 max_stride; + __u8 max_spec; + __u8 udma_count; + __u8 expdb_mask; + __u8 expdb_qtypes; + + __u8 rsvd2[3]; +}; + +struct ionic_qdesc { + __aligned_u64 addr; + __u32 size; + __u16 mask; + __u8 depth_log2; + __u8 stride_log2; +}; + +struct ionic_ah_resp { + __u32 ahid; + __u32 pad; +}; + +struct ionic_cq_req { + struct ionic_qdesc cq[2]; + __u8 udma_mask; + __u8 rsvd[7]; +}; + +struct ionic_cq_resp { + __u32 cqid[2]; + __u8 udma_mask; + __u8 rsvd[7]; +}; + +struct ionic_qp_req { + struct ionic_qdesc sq; + struct ionic_qdesc rq; + __u8 sq_spec; + __u8 rq_spec; + __u8 sq_cmb; + __u8 rq_cmb; + __u8 udma_mask; + __u8 rsvd[3]; +}; + +struct ionic_qp_resp { + __u32 qpid; + __u8 sq_cmb; + __u8 rq_cmb; + __u8 udma_idx; + __u8 rsvd[1]; + __aligned_u64 sq_cmb_offset; + __aligned_u64 rq_cmb_offset; +}; + +struct ionic_srq_req { + struct ionic_qdesc rq; + __u8 rq_spec; + __u8 rq_cmb; + __u8 udma_mask; + __u8 rsvd[5]; +}; + +struct ionic_srq_resp { + __u32 qpid; + __u8 rq_cmb; + __u8 udma_idx; + __u8 rsvd[2]; + __aligned_u64 rq_cmb_offset; +}; + +#endif /* IONIC_ABI_H */ -- cgit v1.3.1