[PATCH] hid: hid-lg4ff: fix possible sleep-in-atomic-context bug
From: Jia-Ju Bai <hidden>
Date: 2019-12-18 08:29:56
Also in:
lkml
Subsystem:
hid core layer, the rest · Maintainers:
Jiri Kosina, Benjamin Tissoires, Linus Torvalds
The driver may sleep while holding a read lock. The function call path (from bottom to top) in Linux 4.19 is: drivers/hid/hid-core.c, 1459: hid_alloc_report_buf(GFP_KERNEL) in __hid_request ./include/linux/hid.h, 1051: __hid_request in hid_hw_request drivers/hid/hid-lg4ff.c, 538: hid_hw_request in lg4ff_set_autocenter_default drivers/hid/hid-lg4ff.c, 497: _raw_spin_lock_irqsave in lg4ff_set_autocenter_default drivers/hid/hid-core.c, 1459: hid_alloc_report_buf(GFP_KERNEL) in __hid_request ./include/linux/hid.h, 1051: __hid_request in hid_hw_request drivers/hid/hid-lg4ff.c, 585: hid_hw_request in lg4ff_set_autocenter_ffex drivers/hid/hid-lg4ff.c, 576: _raw_spin_lock_irqsave in lg4ff_set_autocenter_ffex drivers/hid/hid-core.c, 1459: hid_alloc_report_buf(GFP_KERNEL) in __hid_request ./include/linux/hid.h, 1051: __hid_request in hid_hw_request drivers/hid/hid-lg4ff.c, 1116: hid_hw_request in lg4ff_set_leds drivers/hid/hid-lg4ff.c, 1108: _raw_spin_lock_irqsave in lg4ff_set_leds drivers/hid/hid-core.c, 1459: hid_alloc_report_buf(GFP_KERNEL) in __hid_request ./include/linux/hid.h, 1051: __hid_request in hid_hw_request drivers/hid/hid-lg4ff.c, 465: hid_hw_request in lg4ff_play drivers/hid/hid-lg4ff.c, 441: _raw_spin_lock_irqsave in lg4ff_play drivers/hid/hid-core.c, 1459: hid_alloc_report_buf(GFP_KERNEL) in __hid_request ./include/linux/hid.h, 1051: __hid_request in hid_hw_request drivers/hid/hid-lg4ff.c, 664: hid_hw_request in lg4ff_set_range_dfp drivers/hid/hid-lg4ff.c, 648: _raw_spin_lock_irqsave in lg4ff_set_range_dfp drivers/hid/hid-core.c, 1459: hid_alloc_report_buf(GFP_KERNEL) in __hid_request ./include/linux/hid.h, 1051: __hid_request in hid_hw_request drivers/hid/hid-lg4ff.c, 620: hid_hw_request in lg4ff_set_range_g25 drivers/hid/hid-lg4ff.c, 611: _raw_spin_lock_irqsave in lg4ff_set_range_g25 hid_alloc_report_buf(GFP_KERNEL) can sleep at runtime. To fix these bugs, hid_hw_request() is called without holding the spinlock. These bugs are found by a static analysis tool STCheck written by myself. Signed-off-by: Jia-Ju Bai <redacted> --- drivers/hid/hid-lg4ff.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-)
diff --git a/drivers/hid/hid-lg4ff.c b/drivers/hid/hid-lg4ff.c
index 5e6a0cef2a06..047a19da3aed 100644
--- a/drivers/hid/hid-lg4ff.c
+++ b/drivers/hid/hid-lg4ff.c@@ -443,8 +443,8 @@ static int lg4ff_play(struct input_dev *dev, void *data, struct ff_effect *effec value[5] = 0x00; value[6] = 0x00; - hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT); spin_unlock_irqrestore(&entry->report_lock, flags); + hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT); return 0; }
@@ -456,8 +456,8 @@ static int lg4ff_play(struct input_dev *dev, void *data, struct ff_effect *effec value[5] = 0x00; value[6] = 0x00; - hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT); spin_unlock_irqrestore(&entry->report_lock, flags); + hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT); break; } return 0;
@@ -498,8 +498,8 @@ static void lg4ff_set_autocenter_default(struct input_dev *dev, u16 magnitude) value[5] = 0x00; value[6] = 0x00; - hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT); spin_unlock_irqrestore(&entry->report_lock, flags); + hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT); return; }
@@ -529,7 +529,9 @@ static void lg4ff_set_autocenter_default(struct input_dev *dev, u16 magnitude) value[5] = 0x00; value[6] = 0x00; + spin_unlock_irqrestore(&entry->report_lock, flags); hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT); + spin_lock_irqsave(&entry->report_lock, flags); /* Activate Auto-Center */ value[0] = 0x14;
@@ -540,8 +542,8 @@ static void lg4ff_set_autocenter_default(struct input_dev *dev, u16 magnitude) value[5] = 0x00; value[6] = 0x00; - hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT); spin_unlock_irqrestore(&entry->report_lock, flags); + hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT); } /* Sends autocentering command compatible with Formula Force EX */
@@ -576,8 +578,8 @@ static void lg4ff_set_autocenter_ffex(struct input_dev *dev, u16 magnitude) value[5] = 0x00; value[6] = 0x00; - hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT); spin_unlock_irqrestore(&entry->report_lock, flags); + hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT); } /* Sends command to set range compatible with G25/G27/Driving Force GT */
@@ -611,8 +613,8 @@ static void lg4ff_set_range_g25(struct hid_device *hid, u16 range) value[5] = 0x00; value[6] = 0x00; - hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT); spin_unlock_irqrestore(&entry->report_lock, flags); + hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT); } /* Sends commands to set range compatible with Driving Force Pro wheel */
@@ -655,7 +657,9 @@ static void lg4ff_set_range_dfp(struct hid_device *hid, u16 range) value[1] = 0x02; full_range = 200; } + spin_unlock_irqrestore(&entry->report_lock, flags); hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT); + spin_lock_irqsave(&entry->report_lock, flags); /* Prepare "fine" limit command */ value[0] = 0x81;
@@ -667,8 +671,8 @@ static void lg4ff_set_range_dfp(struct hid_device *hid, u16 range) value[6] = 0x00; if (range == 200 || range == 900) { /* Do not apply any fine limit */ - hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT); spin_unlock_irqrestore(&entry->report_lock, flags); + hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT); return; }
@@ -682,8 +686,8 @@ static void lg4ff_set_range_dfp(struct hid_device *hid, u16 range) value[5] = (start_right & 0xe) << 4 | (start_left & 0xe); value[6] = 0xff; - hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT); spin_unlock_irqrestore(&entry->report_lock, flags); + hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT); } static const struct lg4ff_compat_mode_switch *lg4ff_get_mode_switch_command(const u16 real_product_id, const u16 target_product_id)
@@ -1107,8 +1111,8 @@ static void lg4ff_set_leds(struct hid_device *hid, u8 leds) value[4] = 0x00; value[5] = 0x00; value[6] = 0x00; - hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT); spin_unlock_irqrestore(&entry->report_lock, flags); + hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT); } static void lg4ff_led_set_brightness(struct led_classdev *led_cdev,
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2.17.1