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| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-09-01 19:37:34 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-09-05 14:01:34 +0300 |
| commit | 5666a274a6d54372d6b79b1f78682a9d827e679e (patch) | |
| tree | 7ce89c420972c5129c79d6d20d2c4038076c6ae9 /drivers/base/driver.c | |
| parent | c749b275056d4d1023af125b320c91a24d6856b8 (diff) | |
| download | linux-5666a274a6d54372d6b79b1f78682a9d827e679e.tar.xz | |
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.c | 6 |
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); |