The driver may sleep with holding a spinlock.
The function call paths (from bottom to top) in Linux-4.16 are:
[FUNC] hid_alloc_report_buf(GFP_KERNEL)
drivers/hid/hid-core.c, 1435:
hid_alloc_report_buf in __hid_request
./include/linux/hid.h, 1023:
__hid_request in hid_hw_request
drivers/hid/hid-picolcd_core.c, 111:
hid_hw_request in picolcd_send_and_wait
drivers/hid/hid-picolcd_core.c, 100:
_raw_spin_lock_irqsave in picolcd_send_and_wait
[FUNC] hid_alloc_report_buf(GFP_KERNEL)
drivers/hid/hid-core.c, 1435:
hid_alloc_report_buf in __hid_request
./include/linux/hid.h, 1023:
__hid_request in hid_hw_request
drivers/hid/hid-picolcd_core.c, 245:
hid_hw_request in picolcd_reset
drivers/hid/hid-picolcd_core.c, 235:
_raw_spin_lock_irqsave in picolcd_reset
[FUNC] hid_alloc_report_buf(GFP_KERNEL)
drivers/hid/hid-core.c, 1435:
hid_alloc_report_buf in __hid_request
./include/linux/hid.h, 1023:
__hid_request in hid_hw_request
drivers/hid/hid-picolcd_fb.c, 215:
hid_hw_request in picolcd_fb_reset
drivers/hid/hid-picolcd_fb.c, 206:
_raw_spin_lock_irqsave in picolcd_fb_reset
[FUNC] hid_alloc_report_buf(GFP_KERNEL)
drivers/hid/hid-core.c, 1435:
hid_alloc_report_buf in __hid_request
./include/linux/hid.h, 1023:
__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
To fix this bug, GFP_KERNEL is replaced with GFP_ATOMIC.
This bug is found by my static analysis tool DSAC.
Signed-off-by: Jia-Ju Bai <baijiaju1...@gmail.com>
---
drivers/hid/hid-core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 3942ee61bd1c..c886af00c8c9 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1442,7 +1442,7 @@ void __hid_request(struct hid_device *hid, struct
hid_report *report,
int ret;
u32 len;
- buf = hid_alloc_report_buf(report, GFP_KERNEL);
+ buf = hid_alloc_report_buf(report, GFP_ATOMIC);
if (!buf)
return;
--
2.17.0
