misc: fastrpc: fix DMA address corruption due to find_vma misuse

[ Upstream commit 464c6ad2aa ]

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: 80f3afd72b ("misc: fastrpc: consider address offset before sending to DSP")
Reported-by: Yuhao Jiang <danisjiang@gmail.com>
Signed-off-by: Junrui Luo <moonafterrain@outlook.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Link: https://patch.msgid.link/20260530204528.116920-3-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ adapted `vma_lookup(mm, ptr)` to `find_vma(mm, ptr)` plus a `ptr >= vma->vm_start` guard since `vma_lookup()` does not exist in 5.10 ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Junrui Luo
2026-06-17 15:09:17 -04:00
committed by Greg Kroah-Hartman
parent 77fa80a1b7
commit d43afc412d
+1 -1
View File
@@ -875,7 +875,7 @@ static int fastrpc_get_args(u32 kernel, struct fastrpc_invoke_ctx *ctx)
mmap_read_lock(current->mm);
vma = find_vma(current->mm, ctx->args[i].ptr);
if (vma)
if (vma && ctx->args[i].ptr >= vma->vm_start)
pages[i].addr += (ctx->args[i].ptr & PAGE_MASK) -
vma->vm_start;
mmap_read_unlock(current->mm);