Commit 97adb49f authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'v6.4/vfs.open' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs 

Pull vfs open fixlet from Christian Brauner:
 "EINVAL ist keinmal: This contains the changes to make O_DIRECTORY when
  specified together with O_CREAT an invalid request.

  The wider background is that a regression report about the behavior of
  O_DIRECTORY | O_CREAT was sent to fsdevel about a behavior that was
  changed multiple years and LTS releases earlier during v5.7
  development.

  This has also been covered in

        https://lwn.net/Articles/926782/

  which provides an excellent summary of the discussion"

* tag 'v6.4/vfs.open' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  open: return EINVAL for O_DIRECTORY | O_CREAT
parents e2eff52c 43b45063

fs/open.c

+13 −5
Original line number Diff line number Diff line
@@ -1196,13 +1196,21 @@ inline int build_open_flags(const struct open_how *how, struct open_flags *op) 
	}



	/*

	 * In order to ensure programs get explicit errors when trying to use

	 * O_TMPFILE on old kernels, O_TMPFILE is implemented such that it

	 * looks like (O_DIRECTORY|O_RDWR & ~O_CREAT) to old kernels. But we

	 * have to require userspace to explicitly set it.

	 * Block bugs where O_DIRECTORY | O_CREAT created regular files.

	 * Note, that blocking O_DIRECTORY | O_CREAT here also protects

	 * O_TMPFILE below which requires O_DIRECTORY being raised.

	 */

	if ((flags & (O_DIRECTORY | O_CREAT)) == (O_DIRECTORY | O_CREAT))

		return -EINVAL;



	/* Now handle the creative implementation of O_TMPFILE. */

	if (flags & __O_TMPFILE) {

		if ((flags & O_TMPFILE_MASK) != O_TMPFILE)

		/*

		 * In order to ensure programs get explicit errors when trying

		 * to use O_TMPFILE on old kernels we enforce that O_DIRECTORY

		 * is raised alongside __O_TMPFILE.

		 */

		if (!(flags & O_DIRECTORY))

			return -EINVAL;

		if (!(acc_mode & MAY_WRITE))

			return -EINVAL;

include/uapi/asm-generic/fcntl.h

+0 −1
Original line number Diff line number Diff line
@@ -91,7 +91,6 @@ 


/* a horrid kludge trying to make sure that this will fail on old kernels */

#define O_TMPFILE (__O_TMPFILE | O_DIRECTORY)

#define O_TMPFILE_MASK (__O_TMPFILE | O_DIRECTORY | O_CREAT)      



#ifndef O_NDELAY

#define O_NDELAY	O_NONBLOCK

tools/include/uapi/asm-generic/fcntl.h

+0 −1
Original line number Diff line number Diff line
@@ -91,7 +91,6 @@ 


/* a horrid kludge trying to make sure that this will fail on old kernels */

#define O_TMPFILE (__O_TMPFILE | O_DIRECTORY)

#define O_TMPFILE_MASK (__O_TMPFILE | O_DIRECTORY | O_CREAT)      



#ifndef O_NDELAY

#define O_NDELAY	O_NONBLOCK