From: Rich Felker <dalias@aerifal.cx>
Date: Fri, 6 Feb 2015 04:34:27 +0000 (-0500)
Subject: fix failure of fchmodat to report EOPNOTSUPP in the race path
X-Git-Url: http://nsz.repo.hu/git/?a=commitdiff_plain;ds=inline;h=61b1d102129990f6e903c6ddcf46c7d79d1a1e99;p=musl

fix failure of fchmodat to report EOPNOTSUPP in the race path

in the case where a non-symlink file was replaced by a symlink during
the fchmodat operation with AT_SYMLINK_NOFOLLOW, mode change on the
new symlink target was successfully suppressed, but the error was not
reported. instead, fchmodat simply returned 0.
---

diff --git a/src/stat/fchmodat.c b/src/stat/fchmodat.c
index a894cb69..d94667ae 100644
--- a/src/stat/fchmodat.c
+++ b/src/stat/fchmodat.c
@@ -29,8 +29,10 @@ int fchmodat(int fd, const char *path, mode_t mode, int flag)
 
 	__procfdname(proc, fd2);
 	ret = __syscall(SYS_fstatat, AT_FDCWD, proc, &st, 0);
-	if (!ret && !S_ISLNK(st.st_mode))
-		ret = __syscall(SYS_fchmodat, AT_FDCWD, proc, mode);
+	if (!ret) {
+		if (S_ISLNK(st.st_mode)) ret = -EOPNOTSUPP;
+		else ret = __syscall(SYS_fchmodat, AT_FDCWD, proc, mode);
+	}
 
 	__syscall(SYS_close, fd2);
 	return __syscall_ret(ret);