4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Stefan Wahren <stefan.wahren@xxxxxxxx>
commit 974d4d03fc020af4fa4e9e72a86f0fefa37803c5 upstream.
This fixes a NULL pointer dereference on RPi 2 with multi_v7_defconfig.
The function page_address() could return NULL with enabled CONFIG_HIGHMEM.
So fix this by using kmap() instead.
Signed-off-by: Stefan Wahren <stefan.wahren@xxxxxxxx>
Fixes: 71bad7f08641 ("staging: add bcm2708 vchiq driver")
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
@@ -538,18 +538,20 @@ free_pagelist(PAGELIST_T *pagelist, int
if (head_bytes > actual)
head_bytes = actual;
- memcpy((char *)page_address(pages[0]) +
+ memcpy((char *)kmap(pages[0]) +
pagelist->offset,
fragments,
head_bytes);
+ kunmap(pages[0]);
}
if ((actual >= 0) && (head_bytes < actual) &&
(tail_bytes != 0)) {
- memcpy((char *)page_address(pages[num_pages - 1]) +
+ memcpy((char *)kmap(pages[num_pages - 1]) +
((pagelist->offset + actual) &
(PAGE_SIZE - 1) & ~(g_cache_line_size - 1)),
fragments + g_cache_line_size,
tail_bytes);
+ kunmap(pages[num_pages - 1]);
}
down(&g_free_fragments_mutex);