* [BUG] fs: f2fs: Possible null-pointer dereferences in update_general_status()
@ 2019-07-25 9:49 ` Jia-Ju Bai
0 siblings, 0 replies; 6+ messages in thread
From: Jia-Ju Bai @ 2019-07-25 9:49 UTC (permalink / raw)
To: jaegeuk, yuchao0; +Cc: linux-f2fs-devel, linux-kernel
In update_general_status(), there are two if statements to
check whether SM_I(sbi) is NULL:
LINE 70: if (SM_I(sbi) && SM_I(sbi)->fcc_info)
LINE 78: if (SM_I(sbi) && SM_I(sbi)->dcc_info)
When SM_I(sbi) is NULL, it is used at some places, such as:
LINE 88: reserved_segments(sbi)
return SM_I(sbi)->reserved_segments;
LINE 89: overprovision_segments(sbi)
return SM_I(sbi)->ovp_segments;
LINE 112: MAIN_SEGS(sbi)
(SM_I(sbi)->main_segments)
Thus, possible null-pointer dereferences may occur.
These bugs are found by a static analysis tool STCheck written by us.
I do not know how to correctly fix these bugs, so I only report them.
Best wishes,
Jia-Ju Bai
^ permalink raw reply [flat|nested] 6+ messages in thread
* [f2fs-dev] [BUG] fs: f2fs: Possible null-pointer dereferences in update_general_status()
@ 2019-07-25 9:49 ` Jia-Ju Bai
0 siblings, 0 replies; 6+ messages in thread
From: Jia-Ju Bai @ 2019-07-25 9:49 UTC (permalink / raw)
To: jaegeuk, yuchao0; +Cc: linux-kernel, linux-f2fs-devel
In update_general_status(), there are two if statements to
check whether SM_I(sbi) is NULL:
LINE 70: if (SM_I(sbi) && SM_I(sbi)->fcc_info)
LINE 78: if (SM_I(sbi) && SM_I(sbi)->dcc_info)
When SM_I(sbi) is NULL, it is used at some places, such as:
LINE 88: reserved_segments(sbi)
return SM_I(sbi)->reserved_segments;
LINE 89: overprovision_segments(sbi)
return SM_I(sbi)->ovp_segments;
LINE 112: MAIN_SEGS(sbi)
(SM_I(sbi)->main_segments)
Thus, possible null-pointer dereferences may occur.
These bugs are found by a static analysis tool STCheck written by us.
I do not know how to correctly fix these bugs, so I only report them.
Best wishes,
Jia-Ju Bai
_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [BUG] fs: f2fs: Possible null-pointer dereferences in update_general_status()
2019-07-25 9:49 ` [f2fs-dev] " Jia-Ju Bai
@ 2019-07-26 3:19 ` Chao Yu
-1 siblings, 0 replies; 6+ messages in thread
From: Chao Yu @ 2019-07-26 3:19 UTC (permalink / raw)
To: Jia-Ju Bai, jaegeuk; +Cc: linux-f2fs-devel, linux-kernel
Hi Jiaju,
Thanks for the report, I checked the code, and found it doesn't need to check
SM_I(sbi) pointer, this is because in fill_super() and put_super(), we will call
f2fs_destroy_stats() in prior to f2fs_destroy_segment_manager(), so if current
sbi can still be visited in global stat list, SM_I(sbi) should be released yet.
So anyway, let's remove unneeded check in line 70/78. :)
Thanks,
On 2019/7/25 17:49, Jia-Ju Bai wrote:
> In update_general_status(), there are two if statements to
> check whether SM_I(sbi) is NULL:
> LINE 70: if (SM_I(sbi) && SM_I(sbi)->fcc_info)
> LINE 78: if (SM_I(sbi) && SM_I(sbi)->dcc_info)
>
> When SM_I(sbi) is NULL, it is used at some places, such as:
> LINE 88: reserved_segments(sbi)
> return SM_I(sbi)->reserved_segments;
> LINE 89: overprovision_segments(sbi)
> return SM_I(sbi)->ovp_segments;
> LINE 112: MAIN_SEGS(sbi)
> (SM_I(sbi)->main_segments)
>
> Thus, possible null-pointer dereferences may occur.
>
> These bugs are found by a static analysis tool STCheck written by us.
>
> I do not know how to correctly fix these bugs, so I only report them.
>
>
> Best wishes,
> Jia-Ju Bai
> .
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [f2fs-dev] [BUG] fs: f2fs: Possible null-pointer dereferences in update_general_status()
@ 2019-07-26 3:19 ` Chao Yu
0 siblings, 0 replies; 6+ messages in thread
From: Chao Yu @ 2019-07-26 3:19 UTC (permalink / raw)
To: Jia-Ju Bai, jaegeuk; +Cc: linux-kernel, linux-f2fs-devel
Hi Jiaju,
Thanks for the report, I checked the code, and found it doesn't need to check
SM_I(sbi) pointer, this is because in fill_super() and put_super(), we will call
f2fs_destroy_stats() in prior to f2fs_destroy_segment_manager(), so if current
sbi can still be visited in global stat list, SM_I(sbi) should be released yet.
So anyway, let's remove unneeded check in line 70/78. :)
Thanks,
On 2019/7/25 17:49, Jia-Ju Bai wrote:
> In update_general_status(), there are two if statements to
> check whether SM_I(sbi) is NULL:
> LINE 70: if (SM_I(sbi) && SM_I(sbi)->fcc_info)
> LINE 78: if (SM_I(sbi) && SM_I(sbi)->dcc_info)
>
> When SM_I(sbi) is NULL, it is used at some places, such as:
> LINE 88: reserved_segments(sbi)
> return SM_I(sbi)->reserved_segments;
> LINE 89: overprovision_segments(sbi)
> return SM_I(sbi)->ovp_segments;
> LINE 112: MAIN_SEGS(sbi)
> (SM_I(sbi)->main_segments)
>
> Thus, possible null-pointer dereferences may occur.
>
> These bugs are found by a static analysis tool STCheck written by us.
>
> I do not know how to correctly fix these bugs, so I only report them.
>
>
> Best wishes,
> Jia-Ju Bai
> .
>
_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [BUG] fs: f2fs: Possible null-pointer dereferences in update_general_status()
2019-07-26 3:19 ` [f2fs-dev] " Chao Yu
@ 2019-07-26 3:39 ` Jia-Ju Bai
-1 siblings, 0 replies; 6+ messages in thread
From: Jia-Ju Bai @ 2019-07-26 3:39 UTC (permalink / raw)
To: Chao Yu, jaegeuk; +Cc: linux-f2fs-devel, linux-kernel
On 2019/7/26 11:19, Chao Yu wrote:
> Hi Jiaju,
>
> Thanks for the report, I checked the code, and found it doesn't need to check
> SM_I(sbi) pointer, this is because in fill_super() and put_super(), we will call
> f2fs_destroy_stats() in prior to f2fs_destroy_segment_manager(), so if current
> sbi can still be visited in global stat list, SM_I(sbi) should be released yet.
> So anyway, let's remove unneeded check in line 70/78. :)
Okay, I will send a patch to remove unneeded checks.
Best wishes,
Jia-Ju Bai
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [f2fs-dev] [BUG] fs: f2fs: Possible null-pointer dereferences in update_general_status()
@ 2019-07-26 3:39 ` Jia-Ju Bai
0 siblings, 0 replies; 6+ messages in thread
From: Jia-Ju Bai @ 2019-07-26 3:39 UTC (permalink / raw)
To: Chao Yu, jaegeuk; +Cc: linux-kernel, linux-f2fs-devel
On 2019/7/26 11:19, Chao Yu wrote:
> Hi Jiaju,
>
> Thanks for the report, I checked the code, and found it doesn't need to check
> SM_I(sbi) pointer, this is because in fill_super() and put_super(), we will call
> f2fs_destroy_stats() in prior to f2fs_destroy_segment_manager(), so if current
> sbi can still be visited in global stat list, SM_I(sbi) should be released yet.
> So anyway, let's remove unneeded check in line 70/78. :)
Okay, I will send a patch to remove unneeded checks.
Best wishes,
Jia-Ju Bai
_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2019-07-26 3:43 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-07-25 9:49 [BUG] fs: f2fs: Possible null-pointer dereferences in update_general_status() Jia-Ju Bai
2019-07-25 9:49 ` [f2fs-dev] " Jia-Ju Bai
2019-07-26 3:19 ` Chao Yu
2019-07-26 3:19 ` [f2fs-dev] " Chao Yu
2019-07-26 3:39 ` Jia-Ju Bai
2019-07-26 3:39 ` [f2fs-dev] " Jia-Ju Bai
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