Bug 689218

Summary:	suspicious patch making bookmark permissions compatible with IsOurFile()
Product:	[Fedora] Fedora	Reporter:	Kamil Dudka <kdudka>
Component:	lynx	Assignee:	Thomas E. Dickey <dickey>
Status:	CLOSED WONTFIX	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	low	Docs Contact:
Priority:	low
Version:	rawhide	CC:	kdudka
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:	486070	Environment:
Last Closed:	2011-03-20 17:14:38 UTC	Type:	---
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:	486070
Bug Blocks:

Description Kamil Dudka 2011-03-20 12:02:48 UTC

+++ This bug was initially created as a clone of Bug #486070 +++

--- Additional comment from kdudka on 2010-01-06 12:41:42 CET ---

Created attachment 381962 [details]
gdb trace

Note it does not happen when running lynx as root.

I am able to get over the bug using the following patch:

--- a/src/LYUtils.c
+++ b/src/LYUtils.c
@@ -5849,8 +5849,8 @@ static FILE *OpenHiddenFile(const char *name, const char *mode)
     } else
 #endif
     if (*mode == 'a') {
-       if (IsOurFile(name)
-           && chmod(name, HIDE_CHMOD) == 0)
+       if (/*IsOurFile(name)
+           &&*/ chmod(name, HIDE_CHMOD) == 0)
            fp = fopen(name, mode);
        else if (lstat(name, &data) != 0)
            fp = OpenHiddenFile(name, binary ? BIN_W : TXT_W);

--- Additional comment from dickey on 2010-01-13 02:37:44 CET ---

Created attachment 383388 [details]
diff to make bookmark permissions compatible with IsOurFile()

Comment 1 Kamil Dudka 2011-03-20 12:07:02 UTC

Thomas, while analyzing the patches inside lynx-2.8.7-6.fc15, I discovered something odd in the patch above.  Could you please have a look at the following code?

mode = ((stat_buf.st_mode & HIDE_CHMOD) | 0600);	/* make it writable */

... means the same as:

mode = 0600;

That is, the value of 'mode is' independent of stat_buf.st_mode.  Is that intended?

Comment 2 Thomas E. Dickey 2011-03-20 16:19:58 UTC

yes - it's redundant to "OR" HIDE_CHMOD (which is 0600) and the actual 0600,
but if HIDE_CHMOD were more lax, e.g., 0640, then the result could inherit
a read-bit from stat_buf.st_mode

So (aside from a qualm about the redundancy), it seems to be doing what
I intended, which was to use HIDE_CHMOD to select only the bits that
correspond to a "hidden" file, and then to add back the bits that let
lynx read/write the file.

I'd have used symbols from <sys/stat.h>, however those (especially when
I wrote that 10-12 years ago) have portability issues.

Comment 3 Kamil Dudka 2011-03-20 17:14:38 UTC

Thanks for clarifying that.  So the construction makes sense in case you changed the definition of HIDE_CHMOD in <LYUtils.h> to something else in the future.  Then we can probably close the bug.