From: Junrui Luo Date: Sat, 30 May 2026 20:45:26 +0000 (+0100) Subject: misc: fastrpc: fix DMA address corruption due to find_vma misuse X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=464c6ad2aa16e1e1df9d559289199356493d1e00;p=thirdparty%2Fkernel%2Flinux.git misc: fastrpc: fix DMA address corruption due to find_vma misuse fastrpc_get_args() uses find_vma() to look up the VMA for a user-provided pointer and compute a DMA address offset. When the address falls in a gap before the returned VMA, (ptr & PAGE_MASK) - vma->vm_start underflows, corrupting the DMA address sent to the DSP. Replace find_vma() with vma_lookup(), which returns NULL when the address is not contained within any VMA. Cc: stable@vger.kernel.org Fixes: 80f3afd72bd4 ("misc: fastrpc: consider address offset before sending to DSP") Reported-by: Yuhao Jiang Signed-off-by: Junrui Luo Reviewed-by: Dmitry Baryshkov Signed-off-by: Srinivas Kandagatla Link: https://patch.msgid.link/20260530204528.116920-3-srini@kernel.org Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c index 48f8262af539..cca7489605c5 100644 --- a/drivers/misc/fastrpc.c +++ b/drivers/misc/fastrpc.c @@ -1090,7 +1090,7 @@ static int fastrpc_get_args(u32 kernel, struct fastrpc_invoke_ctx *ctx) pages[i].addr = ctx->maps[i]->dma_addr; mmap_read_lock(current->mm); - vma = find_vma(current->mm, ctx->args[i].ptr); + vma = vma_lookup(current->mm, ctx->args[i].ptr); if (vma) pages[i].addr += (ctx->args[i].ptr & PAGE_MASK) - vma->vm_start;