| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 19/47] driver core: platform: Dont read past the end of "driver_override" buffer | Date | Tue, 10 Oct 2017 21:50:32 +0200 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: Nicolai Stange <nstange@suse.de>
commit bf563b01c2895a4bfd1a29cc5abc67fe706ecffd upstream.
When printing the driver_override parameter when it is 4095 and 4094 bytes long, the printing code would access invalid memory because we need count+1 bytes for printing.
Reject driver_override values of these lengths in driver_override_store().
This is in close analogy to commit 4efe874aace5 ("PCI: Don't read past the end of sysfs "driver_override" buffer") from Sasha Levin.
Fixes: 3d713e0e382e ("driver core: platform: add device binding path 'driver_override'") Signed-off-by: Nicolai Stange <nstange@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/base/platform.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -809,7 +809,8 @@ static ssize_t driver_override_store(str struct platform_device *pdev = to_platform_device(dev); char *driver_override, *old, *cp; - if (count > PATH_MAX) + /* We need to keep extra room for a newline */ + if (count >= (PAGE_SIZE - 1)) return -EINVAL; driver_override = kstrndup(buf, count, GFP_KERNEL);
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