[PATCH v3 1/2] iio: imu: st_lsm6dsx: fix possible lockup in st_lsm6dsx_read_fifo

[PATCH v3 1/2] iio: imu: st_lsm6dsx: fix possible lockup in st_lsm6dsx_read_fifo

[Silvano Seva]

Prevent st_lsm6dsx_read_fifo from falling in an infinite loop in case
pattern_len is equal to zero and the device FIFO is not empty.

Fixes: 290a6ce11d93 ("iio: imu: add support to lsm6dsx driver")
Signed-off-by: Silvano Seva <s.seva@4sigma.it>
---

Changes since v1:
* st_lsm6dsx_read_fifo: moved check for zero pattern_len before fifo_len assignment
* st_lsm6dsx_read_fifo: dropped check for zero fifo_len
* added Fixes tags in commit message

Changes since v2:
* split patch in two parts, one fixing st_lsm6dsx_read_fifo and one fixing
st_lsm6dsx_read_tagged_fifo

 drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
index 0a7cd8c1aa33..480a9b31065c 100644
--- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
+++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
@@ -392,6 +392,9 @@ int st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw *hw)
 	if (fifo_status & cpu_to_le16(ST_LSM6DSX_FIFO_EMPTY_MASK))
 		return 0;
 
+	if (!pattern_len)
+		pattern_len = ST_LSM6DSX_SAMPLE_SIZE;
+
 	fifo_len = (le16_to_cpu(fifo_status) & fifo_diff_mask) *
 		   ST_LSM6DSX_CHAN_SIZE;
 	fifo_len = (fifo_len / pattern_len) * pattern_len;
-- 
2.48.1

[PATCH v3 2/2] iio: imu: st_lsm6dsx: fix possible lockup in st_lsm6dsx_read_tagged_fifo

[Silvano Seva]

Prevent st_lsm6dsx_read_tagged_fifo from falling in an infinite loop in
case pattern_len is equal to zero and the device FIFO is not empty.

Fixes: 801a6e0af0c6 ("iio: imu: st_lsm6dsx: add support to LSM6DSO")
Signed-off-by: Silvano Seva <s.seva@4sigma.it>
---

Changes since v1:
* st_lsm6dsx_read_fifo: moved check for zero pattern_len before fifo_len assignment
* st_lsm6dsx_read_fifo: dropped check for zero fifo_len
* added Fixes tags in commit message

Changes since v2:
* split patch in two parts, one fixing st_lsm6dsx_read_fifo and one fixing
st_lsm6dsx_read_tagged_fifo

 drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
index 480a9b31065c..8a9d2593576a 100644
--- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
+++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
@@ -626,6 +626,9 @@ int st_lsm6dsx_read_tagged_fifo(struct st_lsm6dsx_hw *hw)
 	if (!fifo_len)
 		return 0;
 
+	if (!pattern_len)
+		pattern_len = ST_LSM6DSX_TAGGED_SAMPLE_SIZE;
+
 	for (read_len = 0; read_len < fifo_len; read_len += pattern_len) {
 		err = st_lsm6dsx_read_block(hw,
 					    ST_LSM6DSX_REG_FIFO_OUT_TAG_ADDR,
-- 
2.48.1

Re: [PATCH v3 1/2] iio: imu: st_lsm6dsx: fix possible lockup in st_lsm6dsx_read_fifo

[Jonathan Cameron]

On Tue, 11 Mar 2025 09:49:47 +0100
Silvano Seva <s.seva@4sigma.it> wrote:

> Prevent st_lsm6dsx_read_fifo from falling in an infinite loop in case
> pattern_len is equal to zero and the device FIFO is not empty.
> 
> Fixes: 290a6ce11d93 ("iio: imu: add support to lsm6dsx driver")
> Signed-off-by: Silvano Seva <s.seva@4sigma.it>
I think you could validly have kept Lorenzo's ack given this was
just breaking the patch into two parts. I put it back and applied
these with them marked for stable to the fixes-togreg branch of iio.git

Thanks,

Jonathan

> ---
> 
> Changes since v1:
> * st_lsm6dsx_read_fifo: moved check for zero pattern_len before fifo_len assignment
> * st_lsm6dsx_read_fifo: dropped check for zero fifo_len
> * added Fixes tags in commit message
> 
> Changes since v2:
> * split patch in two parts, one fixing st_lsm6dsx_read_fifo and one fixing
> st_lsm6dsx_read_tagged_fifo
> 
>  drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
> index 0a7cd8c1aa33..480a9b31065c 100644
> --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
> +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
> @@ -392,6 +392,9 @@ int st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw *hw)
>  	if (fifo_status & cpu_to_le16(ST_LSM6DSX_FIFO_EMPTY_MASK))
>  		return 0;
>  
> +	if (!pattern_len)
> +		pattern_len = ST_LSM6DSX_SAMPLE_SIZE;
> +
>  	fifo_len = (le16_to_cpu(fifo_status) & fifo_diff_mask) *
>  		   ST_LSM6DSX_CHAN_SIZE;
>  	fifo_len = (fifo_len / pattern_len) * pattern_len;

Re: [PATCH v3 1/2] iio: imu: st_lsm6dsx: fix possible lockup in st_lsm6dsx_read_fifo

[Silvano Seva]

On Sat, Mar 15, 2025 at 7:36 PM Jonathan Cameron <jic23@kernel.org> wrote:
>
> On Tue, 11 Mar 2025 09:49:47 +0100
> Silvano Seva <s.seva@4sigma.it> wrote:
>
> > Prevent st_lsm6dsx_read_fifo from falling in an infinite loop in case
> > pattern_len is equal to zero and the device FIFO is not empty.
> >
> > Fixes: 290a6ce11d93 ("iio: imu: add support to lsm6dsx driver")
> > Signed-off-by: Silvano Seva <s.seva@4sigma.it>
> I think you could validly have kept Lorenzo's ack given this was
> just breaking the patch into two parts. I put it back and applied
> these with them marked for stable to the fixes-togreg branch of iio.git
>
Yes, sorry. I mistakenly dropped the "acked-by" when splitting the patch.

Thank you,
Silvano.