Attempting to online memory which is already online will cause this: 1. store_mem_state() called with buf="online" 2. device_online() returns 1 because device is already online 3. store_mem_state() returns 1 4. calling code interprets this as 1-byte buffer read 5. store_mem_state() called again with buf="nline" 6. store_mem_state() returns -EINVAL
Example: $ cat /sys/devices/system/memory/memory0/state online $ echo online > /sys/devices/system/memory/memory0/state -bash: echo: write error: Invalid argument Fix the return value of store_mem_state() so this doesn't happen. Signed-off-by: Reza Arbab <[email protected]> --- drivers/base/memory.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 961e2cf..031950f 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -359,9 +359,7 @@ store_mem_state(struct device *dev, err: unlock_device_hotplug(); - if (ret) - return ret; - return count; + return ret < 0 ? ret : count; } /* -- 1.8.3.1
