Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 6e6823d1 authored by Torben Hohn's avatar Torben Hohn Committed by Thomas Gleixner
Browse files

posix-clocks: Check write permissions in posix syscalls 



pc_clock_settime() and pc_clock_adjtime() do not check whether the fd
was opened in write mode, so a clock can be set with a read only fd.

[ tglx: We deliberately do not return -EPERM as we want this to be
  	distingushable from the capability based permission check ]

Signed-off-by: default avatarTorben Hohn <torbenh@gmx.de>
LKML-Reference: <1299173174-348-4-git-send-email-torbenh@gmx.de>
Cc: Richard Cochran <richard.cochran@omicron.at>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
parent a9e7acff

kernel/time/posix-clock.c

+12 −2
Original line number Original line Diff line number Diff line
@@ -287,11 +287,16 @@ static int pc_clock_adjtime(clockid_t id, struct timex *tx) 
	if (err)

	if (err)

		return err;

		return err;





	if ((cd.fp->f_mode & FMODE_WRITE) == 0) {

		err = -EACCES;

		goto out;

	}



	if (cd.clk->ops.clock_adjtime)

	if (cd.clk->ops.clock_adjtime)

		err = cd.clk->ops.clock_adjtime(cd.clk, tx);

		err = cd.clk->ops.clock_adjtime(cd.clk, tx);

	else

	else

		err = -EOPNOTSUPP;

		err = -EOPNOTSUPP;



out:

	put_clock_desc(&cd);

	put_clock_desc(&cd);





	return err;

	return err;
@@ -344,11 +349,16 @@ static int pc_clock_settime(clockid_t id, const struct timespec *ts) 
	if (err)

	if (err)

		return err;

		return err;





	if ((cd.fp->f_mode & FMODE_WRITE) == 0) {

		err = -EACCES;

		goto out;

	}



	if (cd.clk->ops.clock_settime)

	if (cd.clk->ops.clock_settime)

		err = cd.clk->ops.clock_settime(cd.clk, ts);

		err = cd.clk->ops.clock_settime(cd.clk, ts);

	else

	else

		err = -EOPNOTSUPP;

		err = -EOPNOTSUPP;



out:

	put_clock_desc(&cd);

	put_clock_desc(&cd);





	return err;

	return err;