The driver trusts the 'num' and 'entry_size' fields read from BAR2 and uses them directly to compute the length for memcpy_fromio() without any bounds checking. If these fields get corrupted or otherwise contain invalid values, num * entry_size can exceed the size of proc_mon_info.entries and lead to a potential out-of-bounds write.
Add validation for 'entry_size' by ensuring it is non-zero and that num * entry_size does not exceed the size of proc_mon_info.entries.
Fixes: ff428d052b3b ("misc: bcm-vk: add get_card_info, peerlog_info, and proc_mon_info") Cc: stable@vger.kernel.org Signed-off-by: Guangshuo Li lgs201920130244@gmail.com --- drivers/misc/bcm-vk/bcm_vk_dev.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/misc/bcm-vk/bcm_vk_dev.c b/drivers/misc/bcm-vk/bcm_vk_dev.c index a16b99bdaa13..a4a74c10f02b 100644 --- a/drivers/misc/bcm-vk/bcm_vk_dev.c +++ b/drivers/misc/bcm-vk/bcm_vk_dev.c @@ -439,6 +439,7 @@ static void bcm_vk_get_proc_mon_info(struct bcm_vk *vk) struct device *dev = &vk->pdev->dev; struct bcm_vk_proc_mon_info *mon = &vk->proc_mon_info; u32 num, entry_size, offset, buf_size; + size_t max_bytes; u8 *dst;
/* calculate offset which is based on peerlog offset */ @@ -458,6 +459,9 @@ static void bcm_vk_get_proc_mon_info(struct bcm_vk *vk) num, BCM_VK_PROC_MON_MAX); return; } + if (!entry_size || (size_t)num > max_bytes / entry_size) { + return; + } mon->num = num; mon->entry_size = entry_size;