summaryrefslogtreecommitdiff
path: root/drivers/base/driver.c
diff options
context:
space:
mode:
authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-09-01 18:37:34 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-09-05 13:01:34 +0200
commit5666a274a6d54372d6b79b1f78682a9d827e679e (patch)
tree7ce89c420972c5129c79d6d20d2c4038076c6ae9 /drivers/base/driver.c
parentc749b275056d4d1023af125b320c91a24d6856b8 (diff)
downloadlwn-5666a274a6d54372d6b79b1f78682a9d827e679e.tar.gz
lwn-5666a274a6d54372d6b79b1f78682a9d827e679e.zip
driver core: fix driver_set_override() issue with empty strings
Python likes to send an empty string for some sysfs files, including the driver_override field. When commit 23d99baf9d72 ("PCI: Use driver_set_override() instead of open-coding") moved the PCI core to use the driver core function instead of hand-rolling their own handler, this showed up as a regression from some userspace tools, like DPDK. Fix this up by actually looking at the length of the string first instead of trusting that userspace got it correct. Fixes: 23d99baf9d72 ("PCI: Use driver_set_override() instead of open-coding") Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: stable <stable@kernel.org> Reported-by: Stephen Hemminger <stephen@networkplumber.org> Tested-by: Huisong Li <lihuisong@huawei.com> Reviewed-by: Stephen Hemminger <stephen@networkplumber.org> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Link: https://lore.kernel.org/r/20220901163734.3583106-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base/driver.c')
-rw-r--r--drivers/base/driver.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/base/driver.c b/drivers/base/driver.c
index 15a75afe6b84..676b6275d5b5 100644
--- a/drivers/base/driver.c
+++ b/drivers/base/driver.c
@@ -63,6 +63,12 @@ int driver_set_override(struct device *dev, const char **override,
if (len >= (PAGE_SIZE - 1))
return -EINVAL;
+ /*
+ * Compute the real length of the string in case userspace sends us a
+ * bunch of \0 characters like python likes to do.
+ */
+ len = strlen(s);
+
if (!len) {
/* Empty string passed - clear override */
device_lock(dev);