From e26529c3dfe3c83fb3a0c73cc83914fe03e6d103 Mon Sep 17 00:00:00 2001 From: Lee Jones Date: Fri, 26 Nov 2021 10:33:35 +0000 Subject: [PATCH] staging: ion: Prevent incorrect reference counting behavour Supply additional checks in order to prevent unexpected results. Fixes: b892bf75b2034 ("ion: Switch ion to use dma-buf") Suggested-by: Dan Carpenter Signed-off-by: Lee Jones Signed-off-by: Greg Kroah-Hartman --- drivers/staging/android/ion/ion.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c index 237f2922de43..f34248dabaa6 100644 --- a/drivers/staging/android/ion/ion.c +++ b/drivers/staging/android/ion/ion.c @@ -495,6 +495,9 @@ static void *ion_buffer_kmap_get(struct ion_buffer *buffer) void *vaddr; if (buffer->kmap_cnt) { + if (buffer->kmap_cnt == INT_MAX) + return ERR_PTR(-EOVERFLOW); + buffer->kmap_cnt++; return buffer->vaddr; } @@ -515,6 +518,9 @@ static void *ion_handle_kmap_get(struct ion_handle *handle) void *vaddr; if (handle->kmap_cnt) { + if (handle->kmap_cnt == INT_MAX) + return ERR_PTR(-EOVERFLOW); + handle->kmap_cnt++; return buffer->vaddr; }