Date: Fri, 04 Sep 2015 14:09:25 +0000 From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 202892] open with O_CREAT | O_DIRECTORY when path references a symlink Message-ID: <bug-202892-8@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=202892 Bug ID: 202892 Summary: open with O_CREAT | O_DIRECTORY when path references a symlink Product: Base System Version: 11.0-CURRENT Hardware: amd64 OS: Any Status: New Severity: Affects Many People Priority: --- Component: kern Assignee: freebsd-bugs@FreeBSD.org Reporter: freebsd@tom-ridge.com The following test code (thanks R Watson) tries to call open with O_CREAT | O_DIRECTORY, on a path that references a broken symlink. The symlink is removed, a file is created, and the call to open returns with an error ENOTDIR. There are similar strange behaviours. For example, O_CREAT | O_DIRECTORY | O_EXCL on a symlink to a directory will result in the symlink being removed, a file being created, and the call returning with an error. POSIX says "If O_EXCL and O_CREAT are set, and path names a symbolic link, open() shall fail and set errno to [EEXIST], regardless of the contents of the symbolic link. " ( http://pubs.opengroup.org/onlinepubs/009695399/functions/open.html ) but I'm not sure whether FreeBSD aims for compliance here. Even if FreeBSD doesn't aim for compliance, this behaviour possibly breaks a possible POSIX invariant: calls which return with errors do not alter the underlying file system state (here, we get an error, but a symlink is removed and a new file is created). #include <err.h> #include <errno.h> #include <fcntl.h> #include <stdio.h> #include <string.h> #include <unistd.h> int main(int argc, char *argv[]) { int fd; /* Setup. */ if (unlink("broken") <= 0 && errno != ENOENT) err(-1, "unlink(broken)"); if (unlink("target") <= 0 && errno != ENOENT) err(-1, "unlink(target)"); if (symlink("target", "broken") < 0) err(-1, "symlink(target, broken)"); /* Test. */ fd = open("broken", O_CREAT | O_DIRECTORY, 0600); if (fd >= 0) errx(-1, "open(broken, O_CREAT | O_DIRECTORY) - no error"); else printf("Error on open() was %s\n", strerror(errno));  } Thanks -- You are receiving this mail because: You are the assignee for the bug.home | help
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