From a357f376a38bd091eeb7865f35fc4af990553f9d Mon Sep 17 00:00:00 2001 From: Jia-Ju Bai Date: Sat, 1 Sep 2018 16:25:08 +0800 Subject: [PATCH] usb: misc: uss720: Fix two sleep-in-atomic-context bugs BugLink: https://bugs.launchpad.net/bugs/1836117 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 Signed-off-by: Kamal Mostafa Signed-off-by: Kleber Sacilotto de Souza --- drivers/usb/misc/uss720.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/usb/misc/uss720.c b/drivers/usb/misc/uss720.c index 263c97fec708..f7c3058b96b0 100644 --- a/drivers/usb/misc/uss720.c +++ b/drivers/usb/misc/uss720.c @@ -369,7 +369,7 @@ 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; @@ -379,7 +379,7 @@ 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; } -- 2.39.2