Re: Bug#762839: bash without importing shell functions from the environment

[Brian May <brian@microcomaustralia.com.au>]

On 26 September 2014 14:15, Russ Allbery <rra@debian.org> wrote:

That would surprise me.  In one case, you're setting an environment
variable and then running sudo.  In the other case, you're telling sudo to
run the command "echo='() { /bin/echo bar; }' echo foo" via a shell. 

No, I don't think that is the case. I believe sudo interprets those assignments itself (as also shown in man page), and  the error I got clearly shows this to be the case.

brian@aquitard:~$ sudo echo='() { /bin/echo bar; id; }'  ./test.sh

sudo: sorry, you are not allowed to set the following environment variables: echo

My understanding is that sudo doesn't invoke any sort of shell unless you expressly tell it to do so.

aquitard# strace -ff -eprocess sudo A=B date

execve("/usr/bin/sudo", ["sudo", "A=B", "date"], [/* 21 vars */]) = 0

arch_prctl(ARCH_SET_FS, 0x7fc58a68b7a0) = 0

clone(Process 25854 attached (waiting for parent)

Process 25854 resumed (parent 25853 ready)

child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7fc58a68ba70) = 25854

[pid 25854] execve("/bin/date", ["date"], [/* 18 vars */]) = 0

[pid 25854] arch_prctl(ARCH_SET_FS, 0x7fef50d2c700) = 0

Friday 26 September  14:27:51 EST 2014

[pid 25854] exit_group(0)               = ?

Process 25854 detached

--- SIGCHLD (Child exited) @ 0 (0) ---

wait4(25854, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], WNOHANG|WSTOPPED, NULL) = 25854

exit_group(0)                           = ?

--
Brian May <brian@microcomaustralia.com.au>