Bug 1065415

Summary: -sesh replaces /path/to/myshell with /path/to-myshell instead of -myshell
Product: Red Hat Enterprise Linux 6 Reporter: Filip Krska <fkrska>
Component: sudoAssignee: Daniel Kopeček <dkopecek>
Status: CLOSED ERRATA QA Contact: Dalibor Pospíšil <dapospis>
Severity: medium Docs Contact:
Priority: medium    
Version: 6.5CC: dapospis, dspurek, pvrabec
Target Milestone: rcKeywords: EasyFix, Patch
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: sudo-1.8.6p3-13.el6 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
: 1065418 1065423 (view as bug list) Environment:
Last Closed: 2014-10-14 06:46:01 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 994246, 1065418    
Attachments:
Description Flags
sesh loginshell argv[0] replacement patch
fkrska: review?
proposed patch none

Description Filip Krska 2014-02-14 15:53:57 UTC
Created attachment 863319 [details]
sesh loginshell argv[0] replacement patch

Description of problem:

/usr/libexec/sesh if called as -sesh by sudo executes the login shell with wrongly replaced argv[0]. The last "/" is replaced with "-", but the rest of the path remains intact. I expect login shell should be called as "-shell", not "/bin-shell".

This can cause unexpected behaviour e.g. in case /bin/zsh which thinks it was called as /bin-zsh, thus runs in sh emulation mode because bin-zsh starts with "b".

Version-Release number of selected component (if applicable):

sudo-1.8.6p3-12.el6.x86_64

How reproducible:

Always

Steps to Reproduce:
1. add

%wheel	ALL=(ALL) ROLE=unconfined_r TYPE=unconfined_t NOPASSWD: ALL

to sudoers (this triggers sesh, without selinux context specified sesh isn't involved)

2. # chsh -s /bin/zsh

3. # usermod -G wheel zshuser

4. [zshuser@rhel6]~% sudo -i

Actual results:

only

#

prompt is shown, no zsh specific rc scripts are sourced in sh emulation mode
 
In strace we see:

execve("/bin/zsh", ["/bin-zsh"], ...

Expected results:

[root@rhel62]~# 

prompt is shown, zsh is launched without emulation

In strace we see:

execve("/bin/zsh", ["-zsh"], ...

Additional info:

Reproduces in sudo-1.8.8-1.fc20.x86_64 as well

Patch attached

Comment 4 Daniel Kopeček 2014-05-21 10:49:25 UTC
Created attachment 897902 [details]
proposed patch

Comment 8 errata-xmlrpc 2014-10-14 06:46:01 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHBA-2014-1484.html