6.6-stable review patch. If anyone has any objections, please let me know.
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From: Vladimir Moskovkin Vladimir.Moskovkin@kaspersky.com
commit 4e89a4077490f52cde652d17e32519b666abf3a6 upstream.
If the 'buf' array received from the user contains an empty string, the 'length' variable will be zero. Accessing the 'buf' array element with index 'length - 1' will result in a buffer overflow.
Add a check for an empty string.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: e8a60aa7404b ("platform/x86: Introduce support for Systems Management Driver over WMI for Dell Systems") Cc: stable@vger.kernel.org Signed-off-by: Vladimir Moskovkin Vladimir.Moskovkin@kaspersky.com Link: https://lore.kernel.org/r/39973642a4f24295b4a8fad9109c5b08@kaspersky.com Reviewed-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Signed-off-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/platform/x86/dell/dell-wmi-sysman/passobj-attributes.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/platform/x86/dell/dell-wmi-sysman/passobj-attributes.c +++ b/drivers/platform/x86/dell/dell-wmi-sysman/passobj-attributes.c @@ -45,7 +45,7 @@ static ssize_t current_password_store(st int length;
length = strlen(buf); - if (buf[length-1] == '\n') + if (length && buf[length - 1] == '\n') length--;
/* firmware does verifiation of min/max password length,