I think that it's euid which is changed here... Actually your euid is checked to check privilege things like passwd binary. If you do this :- $ ls -l `which passwd` -r-s--x--x 1 root root 16336 Feb 14 2003 /usr/bin/passwd As you can see here that "s" [Superuser bit] is set for this binary and using this program any user can change "/etc/passwd" contents, because when a use runs this binary, euid of the user process is set to the superuser and then it can access and modify "/etc/passwd" file which a normal user can't modify using normal text editors or some other tools... You can refer to book written by Vijay Mukhi [Boundless C] for this stuff. Thanks. Sumit Sharma. On Wed, 01 Sep 2004 Dhiman,Gaurav wrote : > >I hope, if you change the "uid" or "euid" (not sure which one) in >"task_struct" of current process to the uid of root, you process will >have root privileges. This is what "login" user program do, using set >_uid systemcall. > >There are specific significance of uid, euid, suid fields in >task_struct, before modifying them, do check there significance. > >I might be wrong, not sure about it, if I am wrong, please correct me. > >Regards, >Gaurav > > >-----Original Message----- > From: kernelnewbies-bounce@xxxxxxxxxxxx >[mailto:kernelnewbies-bounce@xxxxxxxxxxxx] On Behalf Of Timur Tabi >Sent: Wednesday, September 01, 2004 8:12 PM >To: arjanv@xxxxxxxxxx >Cc: kernelnewbies@xxxxxxxxxxxx >Subject: Re: Can a driver give root privileges to a process? > >Arjan van de Ven wrote: > > > Yes it is possible. The moment you do though your driver will end up >on > > bugtraq pretty fast. I can't believe "lets ignore security"! > >I know I need to consider the security issues before delivering the >product, but I want to at least explore the option first. > >However, I was hoping you would tell me HOW I give root privileges to a >process from a driver. > > >-- >Timur Tabi >Staff Software Engineer >timur.tabi@xxxxxxxxxxx > >-- >Kernelnewbies: Help each other learn about the Linux kernel. >Archive: http://mail.nl.linux.org/kernelnewbies/ >FAQ: http://kernelnewbies.org/faq/ > > > >-- >Kernelnewbies: Help each other learn about the Linux kernel. >Archive: http://mail.nl.linux.org/kernelnewbies/ >FAQ: http://kernelnewbies.org/faq/ >
