[PATCH 4.9 01/62] staging: ion: Prevent incorrect reference counting behavour
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-12-06 15:03:56
Also in:
lkml
From: Lee Jones <redacted>
Supply additional checks in order to prevent unexpected results.
Fixes: b892bf75b2034 ("ion: Switch ion to use dma-buf")
Suggested-by: Dan Carpenter <redacted>
Signed-off-by: Lee Jones <redacted>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/staging/android/ion/ion.c | 6 ++++++
1 file changed, 6 insertions(+)
--- a/drivers/staging/android/ion/ion.c
+++ b/drivers/staging/android/ion/ion.c@@ -489,6 +489,9 @@ static void *ion_buffer_kmap_get(struct void *vaddr; if (buffer->kmap_cnt) { + if (buffer->kmap_cnt == INT_MAX) + return ERR_PTR(-EOVERFLOW); + buffer->kmap_cnt++; return buffer->vaddr; }
@@ -509,6 +512,9 @@ static void *ion_handle_kmap_get(struct void *vaddr; if (handle->kmap_cnt) { + if (handle->kmap_cnt == INT_MAX) + return ERR_PTR(-EOVERFLOW); + handle->kmap_cnt++; return buffer->vaddr; }