From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nick Krause Subject: Re: [PATCH] Check for Null return of function of affs_bread in function affs_truncate Date: Fri, 20 Jun 2014 22:25:47 -0400 Message-ID: References: <1403129285-5038-1-git-send-email-xerofoify@gmail.com> <20140619052128.GV5015@mwanda> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: Dan Carpenter , akpm@linux-foundation.org, viro@zeniv.linux.org.uk, fabf@skynet.be, kirill.shutemov@linux.intel.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org To: Thomas Gleixner Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Thanks for standing up for me Thomas. If you have any ideas about what is better please let me known. Cheers Nick On Fri, Jun 20, 2014 at 7:59 PM, Thomas Gleixner wrote: > On Fri, 20 Jun 2014, Nick Krause wrote: > >> Ok that's fine I would return as if it's a NULL the other parts of the >> function can't continue. >> Nick >> >> On Thu, Jun 19, 2014 at 1:21 AM, Dan Carpenter wrote: >> > On Wed, Jun 18, 2014 at 06:08:05PM -0400, Nicholas Krause wrote: >> >> Signed-off-by: Nicholas Krause >> >> --- >> >> fs/affs/file.c | 2 ++ >> >> 1 file changed, 2 insertions(+) >> >> >> >> diff --git a/fs/affs/file.c b/fs/affs/file.c >> >> index a7fe57d..f26482d 100644 >> >> --- a/fs/affs/file.c >> >> +++ b/fs/affs/file.c >> >> @@ -923,6 +923,8 @@ affs_truncate(struct inode *inode) >> >> >> >> while (ext_key) { >> >> ext_bh = affs_bread(sb, ext_key); >> >> + if (!ext_bh) >> >> + return; >> > >> > The problem is that we don't know if we should return here or break >> > here. If you don't understand the code, then it's best to just leave it >> > alone. > > Dan, what kind of attitude is that? > > Nick certainly found an issue where a possible NULL return from > affs_bread() can cause havoc. > > Do YOU understand that code? > > If yes, you better explain, WHY Nicks finding is a false positive > instead of just telling him off in a very inpolite way. > > If not, you better refrain from telling a reporter that he does not > understand the code and should stay away. > > You clearly stated that you do not understand it either: > >> > The problem is that we don't know if we should return here or break >> > here. > > The problem here is that proceeding with a known NULL pointer is wrong > to begin with. It does not matter at all whether break or return is > the proper thing to do. What matters is that proceeding with a NULL > pointer is wrong to begin with, no matter what. > > So either explain why this is a non issue and the NULL pointer return > cannot happen or shut up and try to find a proper solution for that > "return" vs. "break" issue. > > Thanks, > > tglx