diff options
| author | Sasikantha babu <sasikanth.v19@gmail.com> | 2012-03-21 20:10:54 +0530 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2012-03-30 15:43:33 +0200 |
| commit | aa2bf9bc6414b6972b9e51903c1ce7b1f057aee2 (patch) | |
| tree | 71bde0e8c10be9e425a5bba631a0fe033ba2245f | |
| parent | f52b69f86e27903d6896ed5fa7cd280fec8de532 (diff) | |
itimer: Schedule silent NULL pointer fixup in setitimer() for removal
setitimer() should return -EFAULT if called with an invalid pointer
for value. The current code excludes a NULL pointer from this rule and
silently uses it to stop the timer. This violates the spec.
Warn about user space apps which rely on that feature and schedule it
for removal.
[ tglx: Massaged changelog, warn message and Doc entry ]
Signed-off-by: Sasikantha babu <sasikanth.v19@gmail.com>
Link: http://lkml.kernel.org/r/1332340854-26053-1-git-send-email-sasikanth.v19@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | Documentation/feature-removal-schedule.txt | 8 | ||||
| -rw-r--r-- | kernel/itimer.c | 5 |
2 files changed, 12 insertions, 1 deletions
diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index 0cad4803ffac..32fae81228f2 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -529,3 +529,11 @@ When: 3.5 Why: The old kmap_atomic() with two arguments is deprecated, we only keep it for backward compatibility for few cycles and then drop it. Who: Cong Wang <amwang@redhat.com> + +---------------------------- + +What: setitimer accepts user NULL pointer (value) +When: 3.6 +Why: setitimer is not returning -EFAULT if user pointer is NULL. This + violates the spec. +Who: Sasikantha Babu <sasikanth.v19@gmail.com> diff --git a/kernel/itimer.c b/kernel/itimer.c index 22000c3db0dd..c70369a74b5a 100644 --- a/kernel/itimer.c +++ b/kernel/itimer.c @@ -284,8 +284,11 @@ SYSCALL_DEFINE3(setitimer, int, which, struct itimerval __user *, value, if (value) { if(copy_from_user(&set_buffer, value, sizeof(set_buffer))) return -EFAULT; - } else + } else { memset((char *) &set_buffer, 0, sizeof(set_buffer)); + WARN_ONCE(1, "setitimer: new_value pointer is NULL." + " Misfeature support will be removed\n"); + } error = do_setitimer(which, &set_buffer, ovalue ? &get_buffer : NULL); if (error || !ovalue) |