Re: [PATCH v1] wifi: mt76: mt7615: fix null pointer dereference bug

Lorenzo Bianconi
2024-05-13T16:13:12Z

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> Function mt7615_coredump_work will call vzalloc to allocate a large amount
> of memory space, the size of which is 1300KB. There should be a null
> pointer check after vzalloc. Otherwise, when the memory allocation fails
> and returns NULL, the function will cause kernel crash.
>
> Fixes: de791098459d ("wifi: mt76: mt7615: fix null pointer dereference bug")
> Signed-off-by: Sicong Huang <congei42@163.com>
> ---
> drivers/net/wireless/mediatek/mt76/mt7615/mac.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
> index 7ba789834e8d..04eb52904520 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
> @@ -2341,6 +2341,9 @@ void mt7615_coredump_work(struct work_struct *work)
> }
>
> dump = vzalloc(MT76_CONNAC_COREDUMP_SZ);
> + if(!dump)
> + return;
> +
> data = dump;
>
> while (true) {
> --
> 2.34.1

I guess the kernel will not crash here since we check the dump pointer in the
while loop, we will just flush the msg_list queue.

Regards,
Lorenzo

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