Re: core statement on fexecve, O_EXEC, and O_SEARCH

[manu%netbsd.org@localhost (Emmanuel Dreyfus)]

Alan Barrett <apb%netbsd.org@localhost> wrote:

> The fexecve function could be implemented entirely in libc, 
> via execve(2) on a file name of the form "/proc/self/fd/<N>". 
> Any security concerns around fexecve() also apply to exec of 
> /proc/self/fd/<N>.

I gave a try to this approach. There is an unexpected issue:
for a reason I cannot figure, namei() does not resolve
/proc/self/fd/<N>. Here is a ktrace:

   810      1 t_fexecve CALL  open(0x8048db6,0,0)
   810      1 t_fexecve NAMI  "/usr/bin/touch"
   810      1 t_fexecve RET   open 3
   810      1 t_fexecve CALL  getpid
   810      1 t_fexecve RET   getpid 810/0x32a, 924/0x39c
   810      1 t_fexecve CALL  execve(0xbfbfe66f,0xbfbfea98,0xbfbfeaa4)
   810      1 t_fexecve NAMI  "/proc/self/fd/3"
   810      1 t_fexecve RET   execve -1 errno 2 No such file or
directory


-- 
Emmanuel Dreyfus
http://hcpnet.free.fr/pubz
manu%netbsd.org@localhost