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Re: a problem with git describe

From
Carlo Marcelo Arenas Belón <carenas@gmail.com>
Date
Apr 25, 2022, 08:40 UTC
Message-ID
<20220425084003.nf267feurpqyvmsd@carlos-mbp.lan>
In-Reply-To
<20220425070245.ta6wibzkezlfwzxp@carlos-mbp.lan>
On Mon, Apr 25, 2022 at 12:02:45AM -0700, Carlo Marcelo Arenas Belón wrote:
Show 13 quoted lines
> On Sun, Apr 24, 2022 at 11:39:27PM -0700, Junio C Hamano wrote:
> > Carlo Marcelo Arenas Belón <carenas@gmail.com> writes:
> > 
> > > At that point, though you might as well excempt root from this check
> > 
> > But "root" or any higher-valued account is what needs this kind of
> > protection the most, no?
> 
> correct, and I didn't meant to excempt root from the protection, but
> from the check that requires that the config file ownership matches.
> 
> if the config file is owned by root, we already lost, regardless of what
> uid git is running as.
apologies for my confusing english, hopefully this C is clearer
diff --git a/git-compat-util.h b/git-compat-util.h
index 58fd813bd01..6a385be7d1d 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -440,9 +440,19 @@ static inline int git_offset_1st_component(const char *path)
 static inline int is_path_owned_by_current_uid(const char *path)
 {
 	struct stat st;
+	uid_t euid;
+
 	if (lstat(path, &st))
 		return 0;
-	return st.st_uid == geteuid();
+
+	euid = geteuid();
+	if (!euid && st.st_uid && isatty(0)) {
+		struct stat ttyst;
+		if (!stat(ttyname(0), &ttyst))
+			euid = ttyst.st_uid;
+	}
+
+	return st.st_uid == euid;
 }
 
 #define is_path_owned_by_current_user is_path_owned_by_current_uid

it uses stdin instead not to fall in the issue that was raised by
Gábor, but I am affraid that it might need to check all stdnandles for
a valid tty to be safe, and it looking even more complex.

Carlo
Previous: Carlo Marcelo Arenas BelónNext: Guy Maurel
Message 10 of 23 in “a problem with git describe”
  1. Guy MaurelApr 23, 2022
  2. Philip OakleyApr 23, 2022
  3. Junio C HamanoApr 23, 2022
  4. Junio C HamanoApr 23, 2022
  5. Carlo Marcelo Arenas BelónApr 25, 2022
  6. SZEDER GáborApr 25, 2022
  7. Carlo Marcelo Arenas BelónApr 25, 2022
  8. Junio C HamanoApr 25, 2022
  9. Carlo Marcelo Arenas BelónApr 25, 2022
  10. Carlo Marcelo Arenas BelónApr 25, 2022
  11. Guy MaurelApr 25, 2022
  12. Johannes SchindelinApr 26, 2022
  13. rsbecker@nexbridge.comApr 26, 2022
  14. Carlo ArenasApr 26, 2022
  15. Junio C HamanoApr 26, 2022
  16. Carlo ArenasApr 26, 2022
  17. Johannes SchindelinApr 26, 2022
  18. Junio C HamanoApr 26, 2022
  19. Taylor BlauApr 26, 2022
  20. Johannes SchindelinApr 26, 2022
  21. Taylor BlauApr 26, 2022
  22. Johannes SchindelinApr 26, 2022
  23. Junio C HamanoApr 26, 2022

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