From: Jia-Ju Bai Date: Sat, 1 Sep 2018 08:25:08 +0000 (+0800) Subject: usb: misc: uss720: Fix two sleep-in-atomic-context bugs X-Git-Tag: v4.14.72~74 X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a82200ced75f366e6d0740bf8a6fae3a212ea84c;p=linux usb: misc: uss720: Fix two sleep-in-atomic-context bugs commit bc8acc214d3f1cafebcbcd101a695bbac716595d upstream. async_complete() in uss720.c is a completion handler function for the USB driver. So it should not sleep, but it is can sleep according to the function call paths (from bottom to top) in Linux-4.16. [FUNC] set_1284_register(GFP_KERNEL) drivers/usb/misc/uss720.c, 372: set_1284_register in parport_uss720_frob_control drivers/parport/ieee1284.c, 560: [FUNC_PTR]parport_uss720_frob_control in parport_ieee1284_ack_data_avail drivers/parport/ieee1284.c, 577: parport_ieee1284_ack_data_avail in parport_ieee1284_interrupt ./include/linux/parport.h, 474: parport_ieee1284_interrupt in parport_generic_irq drivers/usb/misc/uss720.c, 116: parport_generic_irq in async_complete [FUNC] get_1284_register(GFP_KERNEL) drivers/usb/misc/uss720.c, 382: get_1284_register in parport_uss720_read_status drivers/parport/ieee1284.c, 555: [FUNC_PTR]parport_uss720_read_status in parport_ieee1284_ack_data_avail drivers/parport/ieee1284.c, 577: parport_ieee1284_ack_data_avail in parport_ieee1284_interrupt ./include/linux/parport.h, 474: parport_ieee1284_interrupt in parport_generic_irq drivers/usb/misc/uss720.c, 116: parport_generic_irq in async_complete Note that [FUNC_PTR] means a function pointer call is used. To fix these bugs, GFP_KERNEL is replaced with GFP_ATOMIC. These bugs are found by my static analysis tool DSAC. Signed-off-by: Jia-Ju Bai Cc: stable Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/misc/uss720.c b/drivers/usb/misc/uss720.c index 8a13b2fcf3e1..03152f98108c 100644 --- a/drivers/usb/misc/uss720.c +++ b/drivers/usb/misc/uss720.c @@ -382,7 +382,7 @@ static unsigned char parport_uss720_frob_control(struct parport *pp, unsigned ch mask &= 0x0f; val &= 0x0f; d = (priv->reg[1] & (~mask)) ^ val; - if (set_1284_register(pp, 2, d, GFP_KERNEL)) + if (set_1284_register(pp, 2, d, GFP_ATOMIC)) return 0; priv->reg[1] = d; return d & 0xf; @@ -392,7 +392,7 @@ static unsigned char parport_uss720_read_status(struct parport *pp) { unsigned char ret; - if (get_1284_register(pp, 1, &ret, GFP_KERNEL)) + if (get_1284_register(pp, 1, &ret, GFP_ATOMIC)) return 0; return ret & 0xf8; }