diff options
| author | Robert Richter <robert.richter@amd.com> | 2011-12-19 16:38:30 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2012-01-06 14:13:51 -0800 |
| commit | 3c681ec96dcc0acd6d5386773b44e6c129919394 (patch) | |
| tree | c4ea80e1369d685c00273087864083b2230adad4 /arch/s390 | |
| parent | 724c6ae2912dbfc5c6a9e309f92b786fbc141462 (diff) | |
oprofile: Fix uninitialized memory access when writing to writing to oprofilefs
commit 913050b91eb94f194392dd797b1ff3779f606ac0 upstream.
If oprofilefs_ulong_from_user() is called with count equals
zero, *val remains unchanged. Depending on the implementation it
might be uninitialized.
Change oprofilefs_ulong_from_user()'s interface to return count
on success. Thus, we are able to return early if count equals
zero which avoids using *val uninitialized. Fixing all users of
oprofilefs_ulong_ from_user().
This follows write syscall implementation when count is zero:
"If count is zero ... [and if] no errors are detected, 0 will be
returned without causing any other effect." (man 2 write)
Reported-By: Mike Waychison <mikew@google.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: oprofile-list <oprofile-list@lists.sourceforge.net>
Link: http://lkml.kernel.org/r/20111219153830.GH16765@erda.amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/oprofile/init.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/s390/oprofile/init.c b/arch/s390/oprofile/init.c index 0e358c2cffe..422110a4385 100644 --- a/arch/s390/oprofile/init.c +++ b/arch/s390/oprofile/init.c @@ -90,7 +90,7 @@ static ssize_t hwsampler_write(struct file *file, char const __user *buf, return -EINVAL; retval = oprofilefs_ulong_from_user(&val, buf, count); - if (retval) + if (retval <= 0) return retval; if (oprofile_started) |