From: Junrui Luo Date: Mon, 1 Jun 2026 07:50:00 +0000 (+0800) Subject: powerpc/spufs: fix out-of-bounds access in spufs_mem_mmap_access() X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=47b87f469a35b5ffc81c16eee6b13a9b6c8d55c6;p=thirdparty%2Fkernel%2Flinux.git powerpc/spufs: fix out-of-bounds access in spufs_mem_mmap_access() spufs_mem_mmap_access() computes the local store offset as address - vma->vm_start, but bounds-checks it against vma->vm_end instead of the local store size. On 64-bit, offset is always well below vma->vm_end, so the clamp never fires and len stays unbounded against the LS_SIZE buffer returned by ctx->ops->get_ls(). Reject offsets at or beyond LS_SIZE and clamp len to the remaining space, mirroring the guard already used by spufs_mem_mmap_fault() and spufs_ps_fault(). Fixes: a352894d0705 ("spufs: use new vm_ops->access to allow local state access from gdb") Reported-by: Yuhao Jiang Cc: stable@vger.kernel.org Signed-off-by: Junrui Luo Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/SYBPR01MB7881EE775E8B51C09F5A29E7AF152@SYBPR01MB7881.ausprd01.prod.outlook.com --- diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c index f6de8c1169d5..de7494748fec 100644 --- a/arch/powerpc/platforms/cell/spufs/file.c +++ b/arch/powerpc/platforms/cell/spufs/file.c @@ -268,10 +268,12 @@ static int spufs_mem_mmap_access(struct vm_area_struct *vma, if (write && !(vma->vm_flags & VM_WRITE)) return -EACCES; + if (offset >= LS_SIZE) + return -EFAULT; if (spu_acquire(ctx)) return -EINTR; - if ((offset + len) > vma->vm_end) - len = vma->vm_end - offset; + if ((offset + len) > LS_SIZE) + len = LS_SIZE - offset; local_store = ctx->ops->get_ls(ctx); if (write) memcpy_toio(local_store + offset, buf, len);