Commit 974d4d03 authored by Stefan Wahren's avatar Stefan Wahren Committed by Greg Kroah-Hartman

staging: vchiq_2835_arm: Fix NULL ptr dereference in free_pagelist

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: default avatarStefan Wahren <stefan.wahren@i2se.com>
Fixes: 71bad7f0 ("staging: add bcm2708 vchiq driver")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent e5f5d0e2
......@@ -612,18 +612,20 @@ free_pagelist(struct vchiq_pagelist_info *pagelistinfo,
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);
......
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