Re: [PATCH] mwifiex: Fix divide error in mwifiex_usb_dnld_fw
From: Eric Dumazet <hidden>
Date: 2021-10-19 04:04:35
Also in:
linux-wireless, lkml
On 10/18/21 8:31 PM, Wan Jiabing wrote:
This patch try to fix bug reported by syzkaller: divide error: 0000 [#1] SMP KASAN CPU: 1 PID: 17 Comm: kworker/1:0 Not tainted 5.15.0-rc5-syzkaller #0 Hardware name: Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events request_firmware_work_func RIP: 0010:mwifiex_write_data_sync drivers/net/wireless/marvell/mwifiex/usb.c:696 [inline] RIP: 0010:mwifiex_prog_fw_w_helper drivers/net/wireless/marvell/mwifiex/usb.c:1437 [inline] RIP: 0010:mwifiex_usb_dnld_fw+0xabd/0x11a0 drivers/net/wireless/marvell/mwifiex/usb.c:1518 Call Trace: _mwifiex_fw_dpc+0x181/0x10a0 drivers/net/wireless/marvell/mwifiex/main.c:542 request_firmware_work_func+0x12c/0x230 drivers/base/firmware_loader/main.c:1081 process_one_work+0x9bf/0x1620 kernel/workqueue.c:2297 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 kthread+0x3c2/0x4a0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Link: https://syzkaller.appspot.com/bug?extid=4e7b6c94d22f4bfca9a0
Please provide a Fixes: tag
quoted hunk ↗ jump to hunk
Reported-and-tested-by: syzbot+4e7b6c94d22f4bfca9a0@syzkaller.appspotmail.com Signed-off-by: Wan Jiabing <redacted> --- drivers/net/wireless/marvell/mwifiex/usb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/drivers/net/wireless/marvell/mwifiex/usb.c b/drivers/net/wireless/marvell/mwifiex/usb.c index 426e39d4ccf0..c24ec27d4057 100644 --- a/drivers/net/wireless/marvell/mwifiex/usb.c +++ b/drivers/net/wireless/marvell/mwifiex/usb.c@@ -693,7 +693,7 @@ static int mwifiex_write_data_sync(struct mwifiex_adapter *adapter, u8 *pbuf, struct usb_card_rec *card = adapter->card; int actual_length, ret; - if (!(*len % card->bulk_out_maxpktsize)) + if (card->bulk_out_maxpktsize && !(*len % card->bulk_out_maxpktsize))
Are you sure this fix is not working around the real bug ? In which cases bulk_out_maxpktsize would be zero ? If this is a valid case, this needs to be explained in the changelog.
(*len)++; /* Send the data block */