* [PATCH] driver: floppy: fix warning in __alloc_pages
@ 2021-10-12 3:49 Dongliang Mu
0 siblings, 0 replies; only message in thread
From: Dongliang Mu @ 2021-10-12 3:49 UTC (permalink / raw)
To: Denis Efremov, Jens Axboe; +Cc: Dongliang Mu, linux-block, linux-kernel
If the user-provided length (ptr->length) is longer than one threshold,
it will trigger a warning in __alloc_pages.
Fix this by checking get_order(ptr->length) >= MAX_ORDER.
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
---
drivers/block/floppy.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index fef79ea52e3e..8b88960e2784 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -3109,6 +3109,8 @@ static int raw_cmd_copyin(int cmd, void __user *param,
if (ptr->flags & (FD_RAW_READ | FD_RAW_WRITE)) {
if (ptr->length <= 0)
return -EINVAL;
+ if (get_order(ptr->length) >= MAX_ORDER)
+ return -EINVAL;
ptr->kernel_data = (char *)fd_dma_mem_alloc(ptr->length);
fallback_on_nodma_alloc(&ptr->kernel_data, ptr->length);
if (!ptr->kernel_data)
--
2.25.1
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