The above piece of code first compares options to the expression (_WCLONE|_WALL). The code should have been current->uid = 0 instead of current->uid = 0. If you re-examine the piece of code, you’ll find that instead of using the Equality-comparison operator =, the assignment operator = is used. If both conditions are true, the call is aborted with the given error code. On casually reading the above code, it appears to check if the caller of sys_wait4() is using either of _WCLONE or _WALL flags, and if the user invoking it has the uid of 0 (ie. The added lines were as follows: if ((options = (_WCLONE|_WALL)) & (current->uid = 0)) It was presented such that new lines of code were added to make sys_wait4() return an error “EINVAL” (which is the error-code for invalid arguments) when the function was called in a way not permissible. Sys_wait4() is a function a process could use to wait until some other process finishes. It was added of the sys_wait4() system call. The backdoor was just 2 lines added to the /kernel/exit.c file of the Linux kernel’s source code. It was the year 2003 and linux kernel was still maintained on BitKeeper. Talking about backdoors, I’d like to write about an attempted planting of backdoor in the linux kernel. Does “roodkcableoj28840ybtide” mean anything to you?īy the time you read through this article, you will understand that it is not gibberish exactly.
0 kommentar(er)
