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| author | Torben Hohn <torbenh@gmx.de> | 2011-03-03 18:26:14 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2011-03-12 21:27:07 +0100 |
| commit | 6e6823d17b157f185be09f4c70181299f9273f0b (patch) | |
| tree | 8a9009e2d54955c1a9c5a033493c8668915d09f8 /kernel/time/posix-clock.c | |
| parent | a9e7acfff0a279792918b7b0de74106e576e9988 (diff) | |
| download | lwn-6e6823d17b157f185be09f4c70181299f9273f0b.tar.gz lwn-6e6823d17b157f185be09f4c70181299f9273f0b.zip | |
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: Torben 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>
Diffstat (limited to 'kernel/time/posix-clock.c')
| -rw-r--r-- | kernel/time/posix-clock.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/kernel/time/posix-clock.c b/kernel/time/posix-clock.c index 04498cbf6002..25028dd4fa18 100644 --- a/kernel/time/posix-clock.c +++ b/kernel/time/posix-clock.c @@ -287,11 +287,16 @@ static int pc_clock_adjtime(clockid_t id, struct timex *tx) if (err) return err; + if ((cd.fp->f_mode & FMODE_WRITE) == 0) { + err = -EACCES; + goto out; + } + if (cd.clk->ops.clock_adjtime) err = cd.clk->ops.clock_adjtime(cd.clk, tx); else err = -EOPNOTSUPP; - +out: put_clock_desc(&cd); return err; @@ -344,11 +349,16 @@ static int pc_clock_settime(clockid_t id, const struct timespec *ts) if (err) return err; + if ((cd.fp->f_mode & FMODE_WRITE) == 0) { + err = -EACCES; + goto out; + } + if (cd.clk->ops.clock_settime) err = cd.clk->ops.clock_settime(cd.clk, ts); else err = -EOPNOTSUPP; - +out: put_clock_desc(&cd); return err; |