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Bug 689218

Summary: suspicious patch making bookmark permissions compatible with IsOurFile()
Product: [Fedora] Fedora Reporter: Kamil Dudka <kdudka>
Component: lynxAssignee: Thomas E. Dickey <dickey>
Status: CLOSED WONTFIX QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: low Docs Contact:
Priority: low    
Version: rawhideCC: 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 13:14:38 EDT Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Bug Depends On: 486070    
Bug Blocks:    

Description Kamil Dudka 2011-03-20 08:02:48 EDT
+++ 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 08:07:02 EDT
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 12:19:58 EDT
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 13:14:38 EDT
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.