From 2d5cff2b4bc567dcaad7ab5b46c973ba534cc062 Mon Sep 17 00:00:00 2001 From: Jia Yao Date: Thu, 12 Jun 2025 22:46:20 +0000 Subject: [PATCH] drm/xe: Fix out-of-bounds field write in MI_STORE_DATA_IMM According to Bspec, bits 0~9 of MI_STORE_DATA_IMM must not exceed 0x3FE. The macro MI_SDI_NUM_QW(x) evaluates to 2 * x + 1, which means the condition 2 * x + 1 <= 0x3FE must be satisfied. Therefore, the maximum valid value for x is 0x1FE, not 0x1FF. v2 - Replace 0x1fe with macro MAX_PTE_PER_SDI (Auld, Matthew & Patelczyk, Maciej) v3 - Change macro MAX_PTE_PER_SDI from 0x1fe to 0x1feU (De Marchi, Lucas) Bspec: 60246 Fixes: 9c44fd5f6e8a ("drm/xe: Add migrate layer functions for SVM support") Cc: Matthew Brost Cc: Brian3 Nguyen Cc: Alex Zuo Cc: Matthew Auld Cc: Maciej Patelczyk Cc: Lucas De Marchi Suggested-by: Shuicheng Lin Signed-off-by: Jia Yao Reviewed-by: Matthew Brost Reviewed-by: Lucas De Marchi Reviewed-by: Maciej Patelczyk Link: https://lore.kernel.org/r/20250612224620.161105-1-jia.yao@intel.com Signed-off-by: Lucas De Marchi (cherry picked from commit c038bdba98c9f6a36378044a9d4385531a194d3e) Signed-off-by: Lucas De Marchi --- drivers/gpu/drm/xe/xe_migrate.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/xe/xe_migrate.c b/drivers/gpu/drm/xe/xe_migrate.c index 8f8e9fdfb2a8..7acdc4c78866 100644 --- a/drivers/gpu/drm/xe/xe_migrate.c +++ b/drivers/gpu/drm/xe/xe_migrate.c @@ -82,7 +82,7 @@ struct xe_migrate { * of the instruction. Subtracting the instruction header (1 dword) and * address (2 dwords), that leaves 0x3FD dwords (0x1FE qwords) for PTE values. */ -#define MAX_PTE_PER_SDI 0x1FE +#define MAX_PTE_PER_SDI 0x1FEU /** * xe_tile_migrate_exec_queue() - Get this tile's migrate exec queue. @@ -1553,15 +1553,17 @@ static u32 pte_update_cmd_size(u64 size) u64 entries = DIV_U64_ROUND_UP(size, XE_PAGE_SIZE); XE_WARN_ON(size > MAX_PREEMPTDISABLE_TRANSFER); + /* * MI_STORE_DATA_IMM command is used to update page table. Each - * instruction can update maximumly 0x1ff pte entries. To update - * n (n <= 0x1ff) pte entries, we need: - * 1 dword for the MI_STORE_DATA_IMM command header (opcode etc) - * 2 dword for the page table's physical location - * 2*n dword for value of pte to fill (each pte entry is 2 dwords) + * instruction can update maximumly MAX_PTE_PER_SDI pte entries. To + * update n (n <= MAX_PTE_PER_SDI) pte entries, we need: + * + * - 1 dword for the MI_STORE_DATA_IMM command header (opcode etc) + * - 2 dword for the page table's physical location + * - 2*n dword for value of pte to fill (each pte entry is 2 dwords) */ - num_dword = (1 + 2) * DIV_U64_ROUND_UP(entries, 0x1ff); + num_dword = (1 + 2) * DIV_U64_ROUND_UP(entries, MAX_PTE_PER_SDI); num_dword += entries * 2; return num_dword; @@ -1577,7 +1579,7 @@ static void build_pt_update_batch_sram(struct xe_migrate *m, ptes = DIV_ROUND_UP(size, XE_PAGE_SIZE); while (ptes) { - u32 chunk = min(0x1ffU, ptes); + u32 chunk = min(MAX_PTE_PER_SDI, ptes); bb->cs[bb->len++] = MI_STORE_DATA_IMM | MI_SDI_NUM_QW(chunk); bb->cs[bb->len++] = pt_offset; -- 2.50.1