Messages in this thread | | | Subject | Re: [PATCH] f2fs: read page index before freeing | From | Chao Yu <> | Date | Mon, 26 Nov 2018 19:07:08 +0800 |
| |
On 2018/11/26 18:28, PanBian wrote: > On Mon, Nov 26, 2018 at 05:13:53PM +0800, Chao Yu wrote: >> Hi Pan, >> >> On 2018/11/22 18:58, Pan Bian wrote: >>> The function truncate_node frees the page with f2fs_put_page. However, >>> the page index is read after that. So, the patch reads the index before >>> freeing the page. >> >> I notice that you found another use-after-free bug in ext4, out of >> curiosity, I'd like to ask how do you find those bugs? by tool or code review? > > I found such bugs by the aid of a tool I wrote recently. I designed a method > to automatically find paired alloc/free functions. With such functions, I > wrote two checkers, one to check mismatched alloc/free bugs, the other to > check use-after-free and double-free bugs.
Excellent! Do you have any plan to open its source or announce it w/ binary to linux kernel developers, I think w/ it we can help to improve kernel's code quality efficiently.
Thanks,
> > Best regards, > Pan Bian > > > . >
| |