Hi Tuo Li,
On Sat, Jul 31, 2021 at 02:28:39PM +0800, Li Tuo wrote:
Hello,
Our static analysis tool finds a possible uninitialized-variable access in the sis driver in Linux 5.14.0-rc3:
At the beginning of the function SiS_SetCRT2FIFO_300(), the variable modeidindex is not initialized. If the following conditions are false, it remains uninitialized. 5346: if(!SiS_Pr->CRT1UsesCustomMode) 5438: if(!SiS_Pr->UseCustomMode)
But it is accessed at: 5466: colorth = SiS_GetColorDepth(SiS_Pr,CRT2ModeNo,modeidindex) >> 1;
I am not quite sure whether this possible uninitialized-variable access is real and how to fix it if it is real. Any feedback would be appreciated, thanks!
First, the report looks correct. There is a path where modeindex may not be initilized. But I find it very hard to care for such an ancient driver. If this was somethign we hit is real life we had heard about it - and the risk of introducing bugs is higher than the the cance that this fixes a real life bug.
So my advice, find something more relevant to look at.
Sam