Re: memory leak in rds_send_probe

Re: memory leak in rds_send_probe

[syzbot]

syzbot has bisected this bug to:

commit af49a63e101eb62376cc1d6bd25b97eb8c691d54
Author: Matthew Wilcox <willy@linux.intel.com>
Date:   Sat May 21 00:03:33 2016 +0000

     radix-tree: change naming conventions in radix_tree_shrink

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=176528c8600000
start commit:   c6dd78fc Merge branch 'x86-urgent-for-linus' of git://git...
git tree:       upstream
final crash:    https://syzkaller.appspot.com/x/report.txt?x=14e528c8600000
console output: https://syzkaller.appspot.com/x/log.txt?x=10e528c8600000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8de7d700ea5ac607
dashboard link: https://syzkaller.appspot.com/bug?extid=5134cdf021c4ed5aaa5f
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=145df0c8600000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=170001f4600000

Reported-by: syzbot+5134cdf021c4ed5aaa5f@syzkaller.appspotmail.com
Fixes: af49a63e101e ("radix-tree: change naming conventions in  
radix_tree_shrink")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

Re: memory leak in rds_send_probe

[Andrew Morton]

On Tue, 23 Jul 2019 15:17:00 -0700 syzbot <syzbot+5134cdf021c4ed5aaa5f@syzkaller.appspotmail.com> wrote:

> syzbot has bisected this bug to:
> 
> commit af49a63e101eb62376cc1d6bd25b97eb8c691d54
> Author: Matthew Wilcox <willy@linux.intel.com>
> Date:   Sat May 21 00:03:33 2016 +0000
> 
>      radix-tree: change naming conventions in radix_tree_shrink
> 
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=176528c8600000
> start commit:   c6dd78fc Merge branch 'x86-urgent-for-linus' of git://git...
> git tree:       upstream
> final crash:    https://syzkaller.appspot.com/x/report.txt?x=14e528c8600000
> console output: https://syzkaller.appspot.com/x/log.txt?x=10e528c8600000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=8de7d700ea5ac607
> dashboard link: https://syzkaller.appspot.com/bug?extid=5134cdf021c4ed5aaa5f
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=145df0c8600000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=170001f4600000
> 
> Reported-by: syzbot+5134cdf021c4ed5aaa5f@syzkaller.appspotmail.com
> Fixes: af49a63e101e ("radix-tree: change naming conventions in  
> radix_tree_shrink")
> 
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection

That's rather hard to believe.  af49a63e101eb6237 simply renames a
couple of local variables.

Re: memory leak in rds_send_probe

[Eric Biggers]

On Tue, Jul 23, 2019 at 03:23:36PM -0700, Andrew Morton wrote:
> On Tue, 23 Jul 2019 15:17:00 -0700 syzbot <syzbot+5134cdf021c4ed5aaa5f@syzkaller.appspotmail.com> wrote:
> 
> > syzbot has bisected this bug to:
> > 
> > commit af49a63e101eb62376cc1d6bd25b97eb8c691d54
> > Author: Matthew Wilcox <willy@linux.intel.com>
> > Date:   Sat May 21 00:03:33 2016 +0000
> > 
> >      radix-tree: change naming conventions in radix_tree_shrink
> > 
> > bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=176528c8600000
> > start commit:   c6dd78fc Merge branch 'x86-urgent-for-linus' of git://git...
> > git tree:       upstream
> > final crash:    https://syzkaller.appspot.com/x/report.txt?x=14e528c8600000
> > console output: https://syzkaller.appspot.com/x/log.txt?x=10e528c8600000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=8de7d700ea5ac607
> > dashboard link: https://syzkaller.appspot.com/bug?extid=5134cdf021c4ed5aaa5f
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=145df0c8600000
> > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=170001f4600000
> > 
> > Reported-by: syzbot+5134cdf021c4ed5aaa5f@syzkaller.appspotmail.com
> > Fixes: af49a63e101e ("radix-tree: change naming conventions in  
> > radix_tree_shrink")
> > 
> > For information about bisection process see: https://goo.gl/tpsmEJ#bisection
> 
> That's rather hard to believe.  af49a63e101eb6237 simply renames a
> couple of local variables.
> 

It's been known for months (basically ever since bisection was added) that about
50% of syzbot bisection results are obviously incorrect, often a commit selected
at random.  Unfortunately, the people actually funded to work on syzbot
apparently don't consider fixing this to be high priority issue, so we have to
live with it for now.  Or until someone volunteers to fix it themselves; source
is at https://github.com/google/syzkaller.

So for now, please don't waste much time on bisection results that look wonky.

But please do pay attention to any bisection results in reminders I've been
sending like "Reminder: 10 open syzbot bugs in foo subsystem", since I've
manually reviewed those to exclude the obviously wrong results...

- Eric