| Message ID | 20180901121659.1257-1-baijiaju1990@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | hid: hid-core: Fix a sleep-in-atomic-context bug in __hid_request() | expand |
On Sat, 1 Sep 2018, Jia-Ju Bai wrote: > 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. Could you please rewrite the changelog so that it's human readable? The above is a bit hard to understand, I think something along the lines of "__hid_request() has to be allocating with GFP_ATOMIC because there are the following callchains leading to __hid_request() being an atomic context: ... a->b->c.._hid_request()" etc. Thanks,
On 2018/9/5 16:29, Jiri Kosina wrote: > On Sat, 1 Sep 2018, Jia-Ju Bai wrote: > >> 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. > Could you please rewrite the changelog so that it's human readable? The > above is a bit hard to understand, I think something along the lines of > "__hid_request() has to be allocating with GFP_ATOMIC because there are > the following callchains leading to __hid_request() being an atomic > context: ... a->b->c.._hid_request()" etc. > Okay, I will send a new patch. Best wishes, Jia-Ju Bai
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;
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 <baijiaju1990@gmail.com> --- drivers/hid/hid-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)