Commit ac5e4875 authored Jun 20, 2018 by Jia-Ju Bai Committed by Greg Kroah-Hartman Jun 28, 2018

staging: rtlwifi: Fix a possible sleep-in-atomic-context bug in _is_fw_read_cmd_down()



The driver may sleep with holding a spinlock.
The function call path (from bottom to top) in Linux-4.16.7 is:

[FUNC] schedule
drivers/staging/rtlwifi/halmac/rtl_halmac.c, 884:
		schedule in _is_fw_read_cmd_down
drivers/staging/rtlwifi/halmac/rtl_halmac.c, 912:
		_is_fw_read_cmd_down in rtl_halmac_send_h2c
drivers/staging/rtlwifi/halmac/rtl_halmac.c, 907:
		_raw_spin_lock_irqsave in rtl_halmac_send_h2c

To fix this bug, schedule() is replaced with mdelay(1).

This bug is found by my static analysis tool (DSAC-2) and checked by
my code review.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 6b142341

drivers/staging/rtlwifi/halmac/rtl_halmac.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -870,7 +870,7 @@ static bool _is_fw_read_cmd_down(struct rtl_priv *rtlpriv, u8 msgbox_num)
		if (valid == 0)
		read_down = true;
		else
		schedule();
		mdelay(1);
		} while ((!read_down) && (retry_cnts--));

		return read_down;