Messages in this thread |  | | From | Yoochan Lee <> | Date | Sat, 31 Dec 2022 22:06:19 +0900 | Subject | Re: [PATCH] misc: hpilo: Fix use-after-free in ilo_open |
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Thanks.
Since I don't have a real device, it is difficult to verify the bug dynamically. However, this type of race condition (i.e., b/w remove device and fops) is prevalently founded recently[1-3]. Therefore, I think this bug can be triggered if a real device exists.
The main reason for this race condition (i.e., b/w detach and fops) is there is no proper lock mechanism. I think the detach device function is delayed until the other operations (e.g., fops) is finished. To this end, I use kref to wait for the other operations.
The tool I am making is currently under development, and it can find the race condition between detach function and fops.
[1] https://lore.kernel.org/lkml/20220919040701.GA302806@ubuntu/ [2] https://lore.kernel.org/lkml/20220919040457.GA302681@ubuntu/ [3] https://lore.kernel.org/lkml/20220919101825.GA313940@ubuntu/
2022년 12월 31일 (토) 오후 8:46, Greg KH <gregkh@linuxfoundation.org>님이 작성: > > On Sat, Dec 31, 2022 at 07:05:36PM +0900, Yoochan Lee wrote: > > Hi, > > > > I haven't tested with a physical device cause I don't have a real device. > > I found this bug through static analysis. > > Then please verify that it actually is a bug and that you have fixed it > properly. To send patches that are broken wastes everyone's time :( > > Also, you did not properly describe how the static analysis happened or > what tools reported it as is required. > > > This type of bug is similar to [1] and [2]. > > > > And I'm sorry that my patch is incorrect. > > It's my first time patching a Linux kernel myself. > > I suggest taking the tutorial on kernelnewbies.org and working in the > drivers/staging/* portion of the kernel first, so that you can learn how > this all works. Do not dive in and assume that fixing issues that a > random tool spits out is even correct to do. > > good luck! > > greg k-h
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