git/list[1] front-page[2] threads[3] people[4] search[5] about
 

[PATCH] Improve the filemode trustability check

From
Torsten Bögershausen <tboegi@web.de>
Date
Nov 19, 2014, 15:10 UTC
Message-ID
<546CB2F8.7040501@web.de>
Some file systems do not support the executable bit:
a) The user executable bit is always 0, e.g. VFAT mounted with -onoexec
b) The user executable bit is always 1, e.g. cifs mounted with -ofile_mode=0755
c) There are system where user executable bit is 1 even if it should be 0
   like b), but the file mode can be maintained locally. chmod -x changes the
   file mode from 0766 to 0666, until the file system is unmounted and
   remounted and the file mode is 0766 again.
   This been observed when a Windows machine with NTFS exports a share to
   Mac OS X via smb or afp.

Case a) and b) are handled by the current code. Case c) qualifies as "non trustable executable bit" and core.filemode should be false, but this is not done.

Solution: Detect when ".git/config" has the user executable bit set after creat(".git/config", 0666) and set core.filemode to false.

Signed-off-by: Torsten Bögershausen <tboegi@web.de>
---
This should go on top of "mh/config-flip-xbit-back-after-checking"

Michael, thanks for the test case. And no, I havent seen any systems with behaving like d)

 builtin/init-db.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/builtin/init-db.c b/builtin/init-db.c
index aab44d2..9b50dde 100644
--- a/builtin/init-db.c
+++ b/builtin/init-db.c
@@ -252,10 +252,10 @@ static int create_default_files(const char *template_path)
 	filemode = TEST_FILEMODE;
 	if (TEST_FILEMODE && !lstat(path, &st1)) {
 		struct stat st2;
-		filemode = (!chmod(path, st1.st_mode ^ S_IXUSR) &&
+		filemode = (!chmod(path, st1.st_mode | S_IXUSR) &&
 				!lstat(path, &st2) &&
 				st1.st_mode != st2.st_mode &&
-				!chmod(path, st1.st_mode));
+				!chmod(path, st1.st_mode & (~S_IXUSR)));
 	}
 	git_config_set("core.filemode", filemode ? "true" : "false");
 
-- 
1.9.1.dirty
Next: Junio C Hamano
Message 1 of 2 in “Improve the filemode trustability check”
  1. Improve the filemode trustability checkTorsten Bögershausen, Nov 19, 2014
  2. Junio C HamanoNov 19, 2014

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.