From: Pat Thoyts <hidden> Date: 2016-06-15 23:01:37
David Aguilar [off-list ref] writes:
quoted hunk
gitk uses a predictable ".gitk-tmp.$PID" pattern when generating
a temporary directory.
Use "mktemp -d .gitk-tmp.XXXXXX" to harden gitk against someone
seeding /tmp with files matching the pid pattern.
Signed-off-by: David Aguilar <redacted>
---
This issue was brought up during the first review of the previous patch
back in 2009.
http://thread.gmane.org/gmane.comp.version-control.git/132609/focus=132748
This is really [PATCH 2/2] and should be applied on top of my previous
gitk patch.
gitk | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
} else {
set tmpdir $gitdir
}
- set gitktmpdir [file join $tmpdir [format ".gitk-tmp.%s" [pid]]]
+ set gitktmpformat [file join $tmpdir ".gitk-tmp.XXXXXX"]
+ set gitktmpdir [exec mktemp -d $gitktmpformat]
if {[catch {file mkdir $gitktmpdir} err]} {
error_popup "[mc "Error creating temporary directory %s:" $gitktmpdir] $err"
unset gitktmpdir
This is a problem on Windows where we will not have mktemp. In Tcl 8.6
the file command acquired a "file tempfile" command to help with this
kind of issue (https://www.tcl.tk/man/tcl8.6/TclCmd/file.htm#M39) but
for older versions we should probably stick with the existing pattern at
least on Windows.
--
Pat Thoyts http://www.patthoyts.tk/
PGP fingerprint 2C 6E 98 07 2C 59 C8 97 10 CE 11 E6 04 E0 B9 DD
From: brian m. carlson <hidden> Date: 2016-06-15 23:01:37
On Sun, Jun 15, 2014 at 08:51:23AM +0100, Pat Thoyts wrote:
David Aguilar [off-list ref] writes:
quoted
--- a/gitk+++ b/gitk
@@ -3502,7 +3502,8 @@ proc gitknewtmpdir {} {
} else {
set tmpdir $gitdir
}
- set gitktmpdir [file join $tmpdir [format ".gitk-tmp.%s" [pid]]]
+ set gitktmpformat [file join $tmpdir ".gitk-tmp.XXXXXX"]
+ set gitktmpdir [exec mktemp -d $gitktmpformat]
if {[catch {file mkdir $gitktmpdir} err]} {
error_popup "[mc "Error creating temporary directory %s:" $gitktmpdir] $err"
unset gitktmpdir
This is a problem on Windows where we will not have mktemp. In Tcl 8.6
the file command acquired a "file tempfile" command to help with this
kind of issue (https://www.tcl.tk/man/tcl8.6/TclCmd/file.htm#M39) but
for older versions we should probably stick with the existing pattern at
least on Windows.
The existing pattern is a security bug on Unix systems. MITRE (CWE-377)
tells me that it is a vulnerability on Windows as well, so you'd
probably want to come up with a better solution than the existing
pattern.
You also probably want to request a CVE for this, which the Red Hat and
Debian security teams can do for you if you like. Distributions will
likely want to issue security advisories for this.
--
brian m. carlson / brian with sandals: Houston, Texas, US
+1 832 623 2791 | http://www.crustytoothpaste.net/~bmc | My opinion only
OpenPGP: RSA v4 4096b: 88AC E9B2 9196 305B A994 7552 F1BA 225C 0223 B187
From: David Aguilar <hidden> Date: 2016-06-15 23:01:38
On Sun, Jun 15, 2014 at 04:32:27PM +0000, brian m. carlson wrote:
On Sun, Jun 15, 2014 at 08:51:23AM +0100, Pat Thoyts wrote:
quoted
David Aguilar [off-list ref] writes:
quoted
--- a/gitk+++ b/gitk
@@ -3502,7 +3502,8 @@ proc gitknewtmpdir {} {
} else {
set tmpdir $gitdir
}
- set gitktmpdir [file join $tmpdir [format ".gitk-tmp.%s" [pid]]]
+ set gitktmpformat [file join $tmpdir ".gitk-tmp.XXXXXX"]
+ set gitktmpdir [exec mktemp -d $gitktmpformat]
if {[catch {file mkdir $gitktmpdir} err]} {
error_popup "[mc "Error creating temporary directory %s:" $gitktmpdir] $err"
unset gitktmpdir
This is a problem on Windows where we will not have mktemp. In Tcl 8.6
the file command acquired a "file tempfile" command to help with this
kind of issue (https://www.tcl.tk/man/tcl8.6/TclCmd/file.htm#M39) but
for older versions we should probably stick with the existing pattern at
least on Windows.
The existing pattern is a security bug on Unix systems. MITRE (CWE-377)
tells me that it is a vulnerability on Windows as well, so you'd
probably want to come up with a better solution than the existing
pattern.
You also probably want to request a CVE for this, which the Red Hat and
Debian security teams can do for you if you like. Distributions will
likely want to issue security advisories for this.
I don't think this requires a CVE since it's basically plugging a hole
that my previous patch introduced by making gitk honor the TMPDIR
variable; it hasn't strictly been in any release yet.
Does Git on Windows use a modern tcl?
I checked, and my (old) existing msysgit installation had tcl
8.5, so I unfortunately using "file tempname" won't help there.
Hmm.. I guess what I could do is keep the old behavior (having gitk ignore TMPDIR)
on Windows and only use the new code path on non-Windows.
That seems like it'd be the simplest implementation (no need to check versions)
and the least harmful to existing users (avoids a tcl upgrade or mkdtemp installation
for Windows users).
--
David
From: brian m. carlson <hidden> Date: 2016-06-15 23:01:38
On Sun, Jun 15, 2014 at 02:49:29PM -0700, David Aguilar wrote:
I don't think this requires a CVE since it's basically plugging a hole
that my previous patch introduced by making gitk honor the TMPDIR
variable; it hasn't strictly been in any release yet.
Yeah, that's not needed, then. I didn't notice it was the immediately
previous patch. My bad.
Hmm.. I guess what I could do is keep the old behavior (having gitk
ignore TMPDIR) on Windows and only use the new code path on
non-Windows.
That seems like it'd be the simplest implementation (no need to check
versions) and the least harmful to existing users (avoids a tcl
upgrade or mkdtemp installation for Windows users).
Yeah, that would be the safest bet. Maybe a comment to that effect
would be appropriate, so that when Tcl gets upgraded, that change can be
removed.
--
brian m. carlson / brian with sandals: Houston, Texas, US
+1 832 623 2791 | http://www.crustytoothpaste.net/~bmc | My opinion only
OpenPGP: RSA v4 4096b: 88AC E9B2 9196 305B A994 7552 F1BA 225C 0223 B187
From: Thomas Braun <hidden> Date: 2016-06-15 23:01:38
Am 15.06.2014 09:51, schrieb Pat Thoyts:
David Aguilar [off-list ref] writes:
quoted
gitk uses a predictable ".gitk-tmp.$PID" pattern when generating
a temporary directory.
Use "mktemp -d .gitk-tmp.XXXXXX" to harden gitk against someone
seeding /tmp with files matching the pid pattern.
Signed-off-by: David Aguilar <redacted>
---
This issue was brought up during the first review of the previous patch
back in 2009.
http://thread.gmane.org/gmane.comp.version-control.git/132609/focus=132748
This is really [PATCH 2/2] and should be applied on top of my previous
gitk patch.
gitk | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
} else {
set tmpdir $gitdir
}
- set gitktmpdir [file join $tmpdir [format ".gitk-tmp.%s" [pid]]]
+ set gitktmpformat [file join $tmpdir ".gitk-tmp.XXXXXX"]
+ set gitktmpdir [exec mktemp -d $gitktmpformat]
if {[catch {file mkdir $gitktmpdir} err]} {
error_popup "[mc "Error creating temporary directory %s:" $gitktmpdir] $err"
unset gitktmpdir
This is a problem on Windows where we will not have mktemp. In Tcl 8.6
the file command acquired a "file tempfile" command to help with this
kind of issue (https://www.tcl.tk/man/tcl8.6/TclCmd/file.htm#M39) but
for older versions we should probably stick with the existing pattern at
least on Windows.
We could of course add mktemp from http://www.mktemp.org to msysgit.
I can do that if required.
In mingwgitDevEnv we already have the the need for mktemp, and a msys
package, so this is also not a problem.