This is a note to let you know that I've just added the patch titled staging: comedi: comedi_fops: do not call blocking ops when to my staging git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git in the staging-linus branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will hopefully also be merged in Linus's tree for the next -rc kernel release. If you have any questions about this process, please let me know. >From ec251e0aad912594984f440208ed50b9bdff0f9d Mon Sep 17 00:00:00 2001 From: Ian Abbott <abbotti@xxxxxxxxx> Date: Fri, 28 Jul 2017 16:22:31 +0100 Subject: staging: comedi: comedi_fops: do not call blocking ops when !TASK_RUNNING Comedi's read and write file operation handlers (`comedi_read()` and `comedi_write()`) currently call `copy_to_user()` or `copy_from_user()` whilst in the `TASK_INTERRUPTIBLE` state, which falls foul of the `might_fault()` checks when enabled. Fix it by setting the current task state back to `TASK_RUNNING` a bit earlier before calling these functions. Reported-by: Piotr Gregor <piotrgregor@xxxxxxxxxxx> Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> # 4.5+ Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/staging/comedi/comedi_fops.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index ca11be21f64b..34ca7823255d 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -2396,6 +2396,7 @@ static ssize_t comedi_write(struct file *file, const char __user *buf, continue; } + set_current_state(TASK_RUNNING); wp = async->buf_write_ptr; n1 = min(n, async->prealloc_bufsz - wp); n2 = n - n1; @@ -2528,6 +2529,8 @@ static ssize_t comedi_read(struct file *file, char __user *buf, size_t nbytes, } continue; } + + set_current_state(TASK_RUNNING); rp = async->buf_read_ptr; n1 = min(n, async->prealloc_bufsz - rp); n2 = n - n1; -- 2.13.3