* [PATCH 1/1] proc_keys_next should increase position index
@ 2020-01-24 6:25 Vasily Averin
2020-01-27 11:39 ` David Howells
2020-01-30 8:38 ` Jarkko Sakkinen
0 siblings, 2 replies; 8+ messages in thread
From: Vasily Averin @ 2020-01-24 6:25 UTC (permalink / raw)
To: keyrings, linux-security-module
Cc: David Howells, Jarkko Sakkinen, James Morris, Serge E. Hallyn
if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.
https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
---
security/keys/proc.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/security/keys/proc.c b/security/keys/proc.c
index 415f3f1..d0cde66 100644
--- a/security/keys/proc.c
+++ b/security/keys/proc.c
@@ -139,6 +139,8 @@ static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos)
n = key_serial_next(p, v);
if (n)
*_pos = key_node_serial(n);
+ else
+ (*_pos)++;
return n;
}
--
1.8.3.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH 1/1] proc_keys_next should increase position index
2020-01-24 6:25 [PATCH 1/1] proc_keys_next should increase position index Vasily Averin
@ 2020-01-27 11:39 ` David Howells
2020-01-27 19:27 ` Vasily Averin
2020-01-30 8:42 ` [PATCH 1/1] " Jarkko Sakkinen
2020-01-30 8:38 ` Jarkko Sakkinen
1 sibling, 2 replies; 8+ messages in thread
From: David Howells @ 2020-01-27 11:39 UTC (permalink / raw)
To: Vasily Averin
Cc: dhowells, keyrings, linux-security-module, Jarkko Sakkinen,
James Morris, Serge E. Hallyn
I don't see the effect you're talking about with /proc/keys. I see the
following:
[root@andromeda ~]# dd if=/proc/keys bs=40 skip=1
dd: /proc/keys: cannot skip to specified offset
and then it follows up with the normal content with no obvious duplicates (the
lines are numbered ascendingly in the first column).
I think I may be being confused by what you mean by "the last line".
David
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/1] proc_keys_next should increase position index
2020-01-27 11:39 ` David Howells
@ 2020-01-27 19:27 ` Vasily Averin
2020-01-30 10:16 ` [PATCH v2] keys: " Vasily Averin
2020-01-31 17:19 ` David Howells
2020-01-30 8:42 ` [PATCH 1/1] " Jarkko Sakkinen
1 sibling, 2 replies; 8+ messages in thread
From: Vasily Averin @ 2020-01-27 19:27 UTC (permalink / raw)
To: David Howells
Cc: keyrings, linux-security-module, Jarkko Sakkinen, James Morris,
Serge E. Hallyn
On 1/27/20 2:39 PM, David Howells wrote:
> I don't see the effect you're talking about with /proc/keys. I see the
> following:
>
> [root@andromeda ~]# dd if=/proc/keys bs=40 skip=1
> dd: /proc/keys: cannot skip to specified offset
>
> and then it follows up with the normal content with no obvious duplicates (the
> lines are numbered ascendingly in the first column).
>
> I think I may be being confused by what you mean by "the last line".
on unpatched kernel
$ uname -a
Linux vvsx1 5.3.0-26-generic #28~18.04.1-Ubuntu SMP Wed Dec 18 16:40:14 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
$ dd if=/proc/keys bs=1 # VvS: full usual output
0f6bfdf5 I--Q--- 2 perm 3f010000 1000 1000 user 4af2f79ab8848d0a: 740
1fb91b32 I--Q--- 3 perm 1f3f0000 1000 65534 keyring _uid.1000: 2
27589480 I--Q--- 1 perm 0b0b0000 0 0 user invocation_id: 16
2f33ab67 I--Q--- 152 perm 3f030000 0 0 keyring _ses: 2
33f1d8fa I--Q--- 4 perm 3f030000 1000 1000 keyring _ses: 1
3d427fda I--Q--- 2 perm 3f010000 1000 1000 user 69ec44aec7678e5a: 740
3ead4096 I--Q--- 1 perm 1f3f0000 1000 65534 keyring _uid_ses.1000: 1
521+0 records in
521+0 records out
521 bytes copied, 0,00123769 s, 421 kB/s
$ dd if=/proc/keys bs=500 skip=1 # read after lseek in middle of last line
dd: /proc/keys: cannot skip to specified offset
g _uid_ses.1000: 1 <<<< end of last line
3ead4096 I--Q--- 1 perm 1f3f0000 1000 65534 keyring _uid_ses.1000: 1 <<<< and whole last lien again
0+1 records in
0+1 records out
97 bytes copied, 0,000135035 s, 718 kB/s
$ dd if=/proc/keys bs=1000 skip=1 # read after lseek beyond end of file
dd: /proc/keys: cannot skip to specified offset
3ead4096 I--Q--- 1 perm 1f3f0000 1000 65534 keyring _uid_ses.1000: 1 <<<< generates last line
0+1 records in
0+1 records out
76 bytes copied, 0,000119981 s, 633 kB/s
On patched kernel:
[test@localhost ~]$ uname -a
Linux localhost.localdomain 5.5.0-rc6-00151-gd8d014f #8 SMP Fri Jan 24 13:25:06 MSK 2020 x86_64 x86_64 x86_64 GNU/Linux
[test@localhost ~]$ dd if=/proc/keys bs=1
06e8bec5 I--Q--- 4 perm 1f3f0000 1000 65534 keyring _uid.1000: empty
1b7ee8ed I--Q--- 11 perm 3f030000 1000 1000 keyring _ses: 1
2c1a365d I--Q--- 1 perm 1f3f0000 1000 65534 keyring _uid_ses.1000: 1
3f5823b4 I--Q--- 6 perm 3f030000 1000 1000 keyring _ses: 1
286+0 records in
286+0 records out
286 bytes copied, 0,000414581 s, 690 kB/s
[test@localhost ~]$ dd if=/proc/keys bs=270 skip=1 # VvS: read after lseek in middle of last line
dd: /proc/keys: cannot skip to specified offset
yring _ses: 1 <<<< only end of last line was generated, as expected
0+1 records in
0+1 records out
16 bytes copied, 7,7199e-05 s, 207 kB/s
[test@localhost ~]$ dd if=/proc/keys bs=1000 skip=1 # VvS: read after lseek beond end of file
dd: /proc/keys: cannot skip to specified offset
0+0 records in <<<< nothing was generated, as expected
0+0 records out
0 bytes copied, 8,8036e-05 s, 0,0 kB/s
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/1] proc_keys_next should increase position index
2020-01-24 6:25 [PATCH 1/1] proc_keys_next should increase position index Vasily Averin
2020-01-27 11:39 ` David Howells
@ 2020-01-30 8:38 ` Jarkko Sakkinen
1 sibling, 0 replies; 8+ messages in thread
From: Jarkko Sakkinen @ 2020-01-30 8:38 UTC (permalink / raw)
To: Vasily Averin, keyrings, linux-security-module
Cc: David Howells, James Morris, Serge E. Hallyn
On Fri, 2020-01-24 at 09:25 +0300, Vasily Averin wrote:
> if seq_file .next fuction does not change position index,
> read after some lseek can generate unexpected output.
>
> https://bugzilla.kernel.org/show_bug.cgi?id=206283
> Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Similar comments as I gave here:
https://patchwork.kernel.org/patch/11346943/
/Jarkko
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/1] proc_keys_next should increase position index
2020-01-27 11:39 ` David Howells
2020-01-27 19:27 ` Vasily Averin
@ 2020-01-30 8:42 ` Jarkko Sakkinen
1 sibling, 0 replies; 8+ messages in thread
From: Jarkko Sakkinen @ 2020-01-30 8:42 UTC (permalink / raw)
To: David Howells, Vasily Averin
Cc: keyrings, linux-security-module, James Morris, Serge E. Hallyn
On Mon, 2020-01-27 at 11:39 +0000, David Howells wrote:
> I don't see the effect you're talking about with /proc/keys. I see the
> following:
>
> [root@andromeda ~]# dd if=/proc/keys bs=40 skip=1
> dd: /proc/keys: cannot skip to specified offset
>
> and then it follows up with the normal content with no obvious duplicates (the
> lines are numbered ascendingly in the first column).
>
> I think I may be being confused by what you mean by "the last line".
>
> David
The commit message is completely lacking cause and effect. For
similar TPM commit I gave the following remarks:
https://patchwork.kernel.org/patch/11346943/
/Jarkko
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v2] keys: proc_keys_next should increase position index
2020-01-27 19:27 ` Vasily Averin
@ 2020-01-30 10:16 ` Vasily Averin
2020-01-31 17:19 ` David Howells
1 sibling, 0 replies; 8+ messages in thread
From: Vasily Averin @ 2020-01-30 10:16 UTC (permalink / raw)
To: keyrings, linux-security-module
Cc: David Howells, Jarkko Sakkinen, James Morris, Serge E. Hallyn
If seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output:
$ dd if=/proc/keys bs=1 # full usual output
0f6bfdf5 I--Q--- 2 perm 3f010000 1000 1000 user 4af2f79ab8848d0a: 740
1fb91b32 I--Q--- 3 perm 1f3f0000 1000 65534 keyring _uid.1000: 2
27589480 I--Q--- 1 perm 0b0b0000 0 0 user invocation_id: 16
2f33ab67 I--Q--- 152 perm 3f030000 0 0 keyring _ses: 2
33f1d8fa I--Q--- 4 perm 3f030000 1000 1000 keyring _ses: 1
3d427fda I--Q--- 2 perm 3f010000 1000 1000 user 69ec44aec7678e5a: 740
3ead4096 I--Q--- 1 perm 1f3f0000 1000 65534 keyring _uid_ses.1000: 1
521+0 records in
521+0 records out
521 bytes copied, 0,00123769 s, 421 kB/s
$ dd if=/proc/keys bs=500 skip=1 # read after lseek in middle of last line
dd: /proc/keys: cannot skip to specified offset
g _uid_ses.1000: 1 <<<< end of last line
3ead4096 I--Q--- 1 perm 1f3f0000 1000 65534 keyring _uid_ses.1000: 1
<<<< and whole last lien again
0+1 records in
0+1 records out
97 bytes copied, 0,000135035 s, 718 kB/s
$ dd if=/proc/keys bs=1000 skip=1 # read after lseek beyond end of file
dd: /proc/keys: cannot skip to specified offset
3ead4096 I--Q--- 1 perm 1f3f0000 1000 65534 keyring _uid_ses.1000: 1
<<<< generates last line
0+1 records in
0+1 records out
76 bytes copied, 0,000119981 s, 633 kB/s
Cc: stable@vger.kernel.org
Fixes: 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code ...")
https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
---
security/keys/proc.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/security/keys/proc.c b/security/keys/proc.c
index 415f3f1..d0cde66 100644
--- a/security/keys/proc.c
+++ b/security/keys/proc.c
@@ -139,6 +139,8 @@ static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos)
n = key_serial_next(p, v);
if (n)
*_pos = key_node_serial(n);
+ else
+ (*_pos)++;
return n;
}
--
1.8.3.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH v2] keys: proc_keys_next should increase position index
2020-01-27 19:27 ` Vasily Averin
2020-01-30 10:16 ` [PATCH v2] keys: " Vasily Averin
@ 2020-01-31 17:19 ` David Howells
2020-02-01 7:54 ` Vasily Averin
1 sibling, 1 reply; 8+ messages in thread
From: David Howells @ 2020-01-31 17:19 UTC (permalink / raw)
To: Vasily Averin
Cc: dhowells, keyrings, linux-security-module, Jarkko Sakkinen,
James Morris, Serge E. Hallyn
Vasily Averin <vvs@virtuozzo.com> wrote:
> If seq_file .next fuction does not change position index,
"function"
> <<<< and whole last lien again
"line"
I can fix these up for you.
> https://bugzilla.kernel.org/show_bug.cgi?id=206283
I wonder if this should have a tag - it looks kind of out of place without
one, but I can't find one suggested.
David
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2] keys: proc_keys_next should increase position index
2020-01-31 17:19 ` David Howells
@ 2020-02-01 7:54 ` Vasily Averin
0 siblings, 0 replies; 8+ messages in thread
From: Vasily Averin @ 2020-02-01 7:54 UTC (permalink / raw)
To: David Howells
Cc: keyrings, linux-security-module, Jarkko Sakkinen, James Morris,
Serge E. Hallyn
On 1/31/20 8:19 PM, David Howells wrote:
> Vasily Averin <vvs@virtuozzo.com> wrote:
>> If seq_file .next fuction does not change position index,
> "function"
>> <<<< and whole last lien again
> "line"
>
> I can fix these up for you.
thank you!
>> https://bugzilla.kernel.org/show_bug.cgi?id=206283
>
> I wonder if this should have a tag - it looks kind of out of place without
> one, but I can't find one suggested.
Some maintainers of another subsystems asked me to add
Cc: stable@vger.kernel.org
Fixes: 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code ...")
however frankly speaking I do not think it is required in this case.
Thank you,
Vasily Averin
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2020-02-01 7:54 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-01-24 6:25 [PATCH 1/1] proc_keys_next should increase position index Vasily Averin
2020-01-27 11:39 ` David Howells
2020-01-27 19:27 ` Vasily Averin
2020-01-30 10:16 ` [PATCH v2] keys: " Vasily Averin
2020-01-31 17:19 ` David Howells
2020-02-01 7:54 ` Vasily Averin
2020-01-30 8:42 ` [PATCH 1/1] " Jarkko Sakkinen
2020-01-30 8:38 ` Jarkko Sakkinen
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