Hi Shaobo, On Sat, 2017-02-18 at 00:26 -0700, Shaobo wrote: > I am applying a static analysis tool to the Linux device drivers and > got > an error trace of null pointer dereference in > drivers/video/fbdev/sis/init.c starting from function > SiS_SetCRT1FIFO_630: pointer `queuedata` is initialized to NULL at > line > 2409 and could get dereferenced at line 2501 if ModeNo <= 0x13 and > SiS_Pr->ChipType == SIS_730. To be more specific, if ModeNo <= 0x13 > then > the locations (line 2449 or line 2451)where `queuedata` gets updated > to > a non null value is skipped. And if `SiS_Pr->ChipType == SIS_730`, > then > `queuedata` is dereferenced. As you can see, the error trace is only > plausible since it depends on certain conditions. Therefore, I was > wondering if you could confirm it. Thanks for your analysis! I agree with your static code analysis and there is a potential NULL dereference. Please note that I am not really familiar with the details of this driver, so I am not sure what the code SHOULD look like and if this potential dereference can really occur at runtime. Maybe somebody else with a little bit more insight into the details of this driver might want to comment on this? Bye, Manuel -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
