| Message ID | 20250319032305.70340-1-linmq006@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 176fda56d72a267731f82aa4a3aeca430394f10e |
| Headers | show |
| Series | spi: Fix reference count leak in slave_show() | expand |
On Wed, 19 Mar 2025 at 04:23, Miaoqian Lin <linmq006@gmail.com> wrote: > Fix a reference count leak in slave_show() by properly putting the device > reference obtained from device_find_any_child(). > > Fixes: 6c364062bfed ("spi: core: Add support for registering SPI slave controllers") > Fixes: c21b0837983d ("spi: Use device_find_any_child() instead of custom approach") > Signed-off-by: Miaoqian Lin <linmq006@gmail.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Gr{oetje,eeting}s, Geert
On Wed, Mar 19, 2025 at 11:23:04AM +0800, Miaoqian Lin wrote: > Fix a reference count leak in slave_show() by properly putting the device > reference obtained from device_find_any_child(). ... > struct device *child; > + int ret; > > child = device_find_any_child(&ctlr->dev); > - return sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias : NULL); > + ret = sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias : NULL); > + put_device(child); > + > + return ret; Can be written better in case of NULL: child = device_find_any_child(&ctlr->dev); if (child) return sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias); put_device(child); return sysfs_emit(buf, "%s\n", NULL); No variable needed.
On Wed, Mar 19, 2025 at 12:44:33PM +0200, Andy Shevchenko wrote: > On Wed, Mar 19, 2025 at 11:23:04AM +0800, Miaoqian Lin wrote: ... > > struct device *child; > > + int ret; > > > > child = device_find_any_child(&ctlr->dev); > > - return sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias : NULL); > > + ret = sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias : NULL); > > + put_device(child); > > + > > + return ret; > > Can be written better in case of NULL: > > child = device_find_any_child(&ctlr->dev); > if (child) > return sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias); Of course this has to be return sysfs_emit(buf, "%s\n", to_spi_device(child)->modalias); > > put_device(child); > return sysfs_emit(buf, "%s\n", NULL); > > No variable needed.
On Wed, Mar 19, 2025 at 12:45:03PM +0200, Andy Shevchenko wrote: > On Wed, Mar 19, 2025 at 12:44:33PM +0200, Andy Shevchenko wrote: > > On Wed, Mar 19, 2025 at 11:23:04AM +0800, Miaoqian Lin wrote: ... > > > struct device *child; > > > + int ret; > > > > > > child = device_find_any_child(&ctlr->dev); > > > - return sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias : NULL); > > > + ret = sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias : NULL); > > > + put_device(child); > > > + > > > + return ret; > > > > Can be written better in case of NULL: > > > > child = device_find_any_child(&ctlr->dev); > > if (child) > > return sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias); > > Of course this has to be > > return sysfs_emit(buf, "%s\n", to_spi_device(child)->modalias); And I mixed the conditional, but I hope you got the idea... > > > > put_device(child); > > return sysfs_emit(buf, "%s\n", NULL); > > > > No variable needed.
On Wed, Mar 19, 2025 at 11:23:04AM +0800, Miaoqian Lin wrote: > Fix a reference count leak in slave_show() by properly putting the device > reference obtained from device_find_any_child(). > > Fixes: 6c364062bfed ("spi: core: Add support for registering SPI slave controllers") > Fixes: c21b0837983d ("spi: Use device_find_any_child() instead of custom approach") > Signed-off-by: Miaoqian Lin <linmq006@gmail.com> > --- > drivers/spi/spi.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c > index a7a4647717d4..ff07c87dbadc 100644 > --- a/drivers/spi/spi.c > +++ b/drivers/spi/spi.c > @@ -2954,9 +2954,13 @@ static ssize_t slave_show(struct device *dev, struct device_attribute *attr, > struct spi_controller *ctlr = container_of(dev, struct spi_controller, > dev); > struct device *child; > + int ret; > > child = device_find_any_child(&ctlr->dev); > - return sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias : NULL); > + ret = sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias : NULL); > + put_device(child); > + > + return ret; > } > > static ssize_t slave_store(struct device *dev, struct device_attribute *attr, > -- > 2.39.5 (Apple Git-154) > Hi, This is the friendly patch-bot of Greg Kroah-Hartman. You have sent him a patch that has triggered this response. He used to manually respond to these common problems, but in order to save his sanity (he kept writing the same thing over and over, yet to different people), I was created. Hopefully you will not take offence and will fix the problem in your patch and resubmit it so that it can be accepted into the Linux kernel tree. You are receiving this message because of the following common error(s) as indicated below: - You have marked a patch with a "Fixes:" tag for a commit that is in an older released kernel, yet you do not have a cc: stable line in the signed-off-by area at all, which means that the patch will not be applied to any older kernel releases. To properly fix this, please follow the documented rules in the Documentation/process/stable-kernel-rules.rst file for how to resolve this. If you wish to discuss this problem further, or you have questions about how to resolve this issue, please feel free to respond to this email and Greg will reply once he has dug out from the pending patches received from other developers. thanks, greg k-h's patch email bot
On Wed, 19 Mar 2025 11:23:04 +0800, Miaoqian Lin wrote: > Fix a reference count leak in slave_show() by properly putting the device > reference obtained from device_find_any_child(). > > Applied to https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next Thanks! [1/1] spi: Fix reference count leak in slave_show() commit: 176fda56d72a267731f82aa4a3aeca430394f10e All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index a7a4647717d4..ff07c87dbadc 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -2954,9 +2954,13 @@ static ssize_t slave_show(struct device *dev, struct device_attribute *attr, struct spi_controller *ctlr = container_of(dev, struct spi_controller, dev); struct device *child; + int ret; child = device_find_any_child(&ctlr->dev); - return sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias : NULL); + ret = sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias : NULL); + put_device(child); + + return ret; } static ssize_t slave_store(struct device *dev, struct device_attribute *attr,
Fix a reference count leak in slave_show() by properly putting the device reference obtained from device_find_any_child(). Fixes: 6c364062bfed ("spi: core: Add support for registering SPI slave controllers") Fixes: c21b0837983d ("spi: Use device_find_any_child() instead of custom approach") Signed-off-by: Miaoqian Lin <linmq006@gmail.com> --- drivers/spi/spi.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)