* [bug report] f2fs: fix to avoid reading out encrypted data in page cache
@ 2016-07-12 13:29 Dan Carpenter
2016-07-12 15:15 ` Chao Yu
0 siblings, 1 reply; 3+ messages in thread
From: Dan Carpenter @ 2016-07-12 13:29 UTC (permalink / raw)
To: yuchao0; +Cc: linux-f2fs-devel
Hello Chao Yu,
The patch 78682f794479: "f2fs: fix to avoid reading out encrypted
data in page cache" from Jul 3, 2016, leads to the following static
checker warning:
fs/f2fs/data.c:1123 f2fs_mpage_readpages()
error: 'bio' dereferencing possible ERR_PTR()
fs/f2fs/data.c
1093 }
1094 if (bio == NULL) {
1095 bio = f2fs_grab_bio(inode, block_nr, nr_pages);
1096 if (IS_ERR(bio))
^^^^^^^^^^
It's an error pointer.
1097 goto set_error_page;
1098 bio_set_op_attrs(bio, REQ_OP_READ, 0);
1099 }
1100
1101 if (bio_add_page(bio, page, blocksize, 0) < blocksize)
1102 goto submit_and_realloc;
1103
1104 last_block_in_bio = block_nr;
1105 goto next_page;
1106 set_error_page:
1107 SetPageError(page);
1108 zero_user_segment(page, 0, PAGE_SIZE);
1109 unlock_page(page);
1110 goto next_page;
1111 confused:
1112 if (bio) {
1113 __submit_bio(F2FS_I_SB(inode), bio, DATA);
1114 bio = NULL;
1115 }
1116 unlock_page(page);
1117 next_page:
1118 if (pages)
1119 put_page(page);
1120 }
1121 BUG_ON(pages && !list_empty(pages));
1122 if (bio)
1123 __submit_bio(F2FS_I_SB(inode), bio, DATA);
^^^
Dereferenced.
1124 return 0;
regards,
dan carpenter
------------------------------------------------------------------------------
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [bug report] f2fs: fix to avoid reading out encrypted data in page cache
2016-07-12 13:29 [bug report] f2fs: fix to avoid reading out encrypted data in page cache Dan Carpenter
@ 2016-07-12 15:15 ` Chao Yu
2016-07-12 16:44 ` Jaegeuk Kim
0 siblings, 1 reply; 3+ messages in thread
From: Chao Yu @ 2016-07-12 15:15 UTC (permalink / raw)
To: Dan Carpenter, yuchao0; +Cc: linux-f2fs-devel
Hi Dan,
Thanks for your report, please check v2.
Thanks,
On 2016/7/12 21:29, Dan Carpenter wrote:
> Hello Chao Yu,
>
> The patch 78682f794479: "f2fs: fix to avoid reading out encrypted
> data in page cache" from Jul 3, 2016, leads to the following static
> checker warning:
>
> fs/f2fs/data.c:1123 f2fs_mpage_readpages()
> error: 'bio' dereferencing possible ERR_PTR()
>
> fs/f2fs/data.c
> 1093 }
> 1094 if (bio == NULL) {
> 1095 bio = f2fs_grab_bio(inode, block_nr, nr_pages);
> 1096 if (IS_ERR(bio))
> ^^^^^^^^^^
> It's an error pointer.
>
> 1097 goto set_error_page;
> 1098 bio_set_op_attrs(bio, REQ_OP_READ, 0);
> 1099 }
> 1100
> 1101 if (bio_add_page(bio, page, blocksize, 0) < blocksize)
> 1102 goto submit_and_realloc;
> 1103
> 1104 last_block_in_bio = block_nr;
> 1105 goto next_page;
> 1106 set_error_page:
> 1107 SetPageError(page);
> 1108 zero_user_segment(page, 0, PAGE_SIZE);
> 1109 unlock_page(page);
> 1110 goto next_page;
> 1111 confused:
> 1112 if (bio) {
> 1113 __submit_bio(F2FS_I_SB(inode), bio, DATA);
> 1114 bio = NULL;
> 1115 }
> 1116 unlock_page(page);
> 1117 next_page:
> 1118 if (pages)
> 1119 put_page(page);
> 1120 }
> 1121 BUG_ON(pages && !list_empty(pages));
> 1122 if (bio)
> 1123 __submit_bio(F2FS_I_SB(inode), bio, DATA);
> ^^^
> Dereferenced.
>
> 1124 return 0;
>
> regards,
> dan carpenter
>
> ------------------------------------------------------------------------------
> What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic
> patterns at an interface-level. Reveals which users, apps, and protocols are
> consuming the most bandwidth. Provides multi-vendor support for NetFlow,
> J-Flow, sFlow and other flows. Make informed decisions using capacity planning
> reports.http://sdm.link/zohodev2dev
> _______________________________________________
> Linux-f2fs-devel mailing list
> Linux-f2fs-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
>
------------------------------------------------------------------------------
What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic
patterns at an interface-level. Reveals which users, apps, and protocols are
consuming the most bandwidth. Provides multi-vendor support for NetFlow,
J-Flow, sFlow and other flows. Make informed decisions using capacity planning
reports.http://sdm.link/zohodev2dev
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [bug report] f2fs: fix to avoid reading out encrypted data in page cache
2016-07-12 15:15 ` Chao Yu
@ 2016-07-12 16:44 ` Jaegeuk Kim
0 siblings, 0 replies; 3+ messages in thread
From: Jaegeuk Kim @ 2016-07-12 16:44 UTC (permalink / raw)
To: Chao Yu; +Cc: Dan Carpenter, linux-f2fs-devel
Hello,
It seems we can write just one patch to resolve this.
Thoughts?
>From f2bd632963409ff969aa2567a38f42f4b493a4b4 Mon Sep 17 00:00:00 2001
From: Jaegeuk Kim <jaegeuk@kernel.org>
Date: Tue, 12 Jul 2016 09:38:48 -0700
Subject: [PATCH] f2fs: fix ERR_PTR returned by bio
This is to fix wrong error pointer handling flow reported by Dan.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
fs/f2fs/data.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 9017366..991ce21 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1137,8 +1137,10 @@ submit_and_realloc:
}
if (bio == NULL) {
bio = f2fs_grab_bio(inode, block_nr, nr_pages);
- if (IS_ERR(bio))
+ if (IS_ERR(bio)) {
+ bio = NULL;
goto set_error_page;
+ }
}
if (bio_add_page(bio, page, blocksize, 0) < blocksize)
--
2.8.3
------------------------------------------------------------------------------
What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic
patterns at an interface-level. Reveals which users, apps, and protocols are
consuming the most bandwidth. Provides multi-vendor support for NetFlow,
J-Flow, sFlow and other flows. Make informed decisions using capacity planning
reports.http://sdm.link/zohodev2dev
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2016-07-12 13:29 [bug report] f2fs: fix to avoid reading out encrypted data in page cache Dan Carpenter
2016-07-12 15:15 ` Chao Yu
2016-07-12 16:44 ` Jaegeuk Kim
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