From: Jia-Ju Bai <baijiaju1990@gmail.com>
To: jikos@kernel.org, benjamin.tissoires@redhat.com
Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
Jia-Ju Bai <baijiaju1990@gmail.com>
Subject: [PATCH V2] hid: hid-core: Fix a sleep-in-atomic-context bug in __hid_request()
Date: Thu, 13 Sep 2018 11:34:32 +0800 [thread overview]
Message-ID: <20180913033432.16336-1-baijiaju1990@gmail.com> (raw)
hid_alloc_report_buf() has to be called with GFP_ATOMIC in
__hid_request(), because there are the following callchains
leading to __hid_request() being an atomic context:
picolcd_send_and_wait (acquire a spinlock)
hid_hw_request
__hid_request
hid_alloc_report_buf(GFP_KERNEL)
picolcd_reset (acquire a spinlock)
hid_hw_request
__hid_request
hid_alloc_report_buf(GFP_KERNEL)
lg4ff_play (acquire a spinlock)
hid_hw_request
__hid_request
hid_alloc_report_buf(GFP_KERNEL)
lg4ff_set_autocenter_ffex (acquire a spinlock)
hid_hw_request
__hid_request
hid_alloc_report_buf(GFP_KERNEL)
This bug is found by my static analysis tool DSAC.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
v2:
* Make the description more human readable.
Thanks Jiri for good advice.
---
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
next reply other threads:[~2018-09-13 3:34 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-13 3:34 Jia-Ju Bai [this message]
2018-09-24 9:26 ` [PATCH V2] hid: hid-core: Fix a sleep-in-atomic-context bug in __hid_request() Jiri Kosina
2018-09-29 9:00 ` Jia-Ju Bai
2018-09-29 19:20 ` Jiri Kosina
2018-10-04 3:14 ` Jia-Ju Bai
2018-10-04 7:35 ` Jiri Kosina
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