* [PATCH] staging: lustre: lustre: obdclass: lprocfs_status.c: Fix for possible null pointer dereference
@ 2014-12-14 22:36 Rickard Strandqvist
2014-12-14 22:39 ` Greg Kroah-Hartman
0 siblings, 1 reply; 9+ messages in thread
From: Rickard Strandqvist @ 2014-12-14 22:36 UTC (permalink / raw)
To: Oleg Drokin, Andreas Dilger
Cc: Rickard Strandqvist, Greg Kroah-Hartman, Julia Lawall,
Greg Donald, John L. Hammond, Andriy Skulysh, Fabian Frederick,
James Simmons, HPDD-discuss, devel, linux-kernel
There is otherwise a risk of a possible null pointer dereference.
Was largely found by using a static code analysis program called cppcheck.
Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
---
.../lustre/lustre/obdclass/lprocfs_status.c | 20 +++++++++-----------
1 file changed, 9 insertions(+), 11 deletions(-)
diff --git a/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c b/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
index 61e04af..4a7891a 100644
--- a/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
+++ b/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
@@ -1897,17 +1897,15 @@ int lprocfs_write_frac_u64_helper(const char *buffer, unsigned long count,
}
units = 1;
- switch (*end) {
- case 'p': case 'P':
- units <<= 10;
- case 't': case 'T':
- units <<= 10;
- case 'g': case 'G':
- units <<= 10;
- case 'm': case 'M':
- units <<= 10;
- case 'k': case 'K':
- units <<= 10;
+ if (end) {
+ switch (*end) {
+ case 'p': case 'P':
+ case 't': case 'T':
+ case 'g': case 'G':
+ case 'm': case 'M':
+ case 'k': case 'K':
+ units <<= 10;
+ }
}
/* Specified units override the multiplier */
if (units)
--
1.7.10.4
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PATCH] staging: lustre: lustre: obdclass: lprocfs_status.c: Fix for possible null pointer dereference
2014-12-14 22:36 [PATCH] staging: lustre: lustre: obdclass: lprocfs_status.c: Fix for possible null pointer dereference Rickard Strandqvist
@ 2014-12-14 22:39 ` Greg Kroah-Hartman
2014-12-14 22:43 ` Rickard Strandqvist
0 siblings, 1 reply; 9+ messages in thread
From: Greg Kroah-Hartman @ 2014-12-14 22:39 UTC (permalink / raw)
To: Rickard Strandqvist
Cc: Oleg Drokin, Andreas Dilger, Julia Lawall, Greg Donald,
John L. Hammond, Andriy Skulysh, Fabian Frederick, James Simmons,
HPDD-discuss, devel, linux-kernel
On Sun, Dec 14, 2014 at 11:36:22PM +0100, Rickard Strandqvist wrote:
> There is otherwise a risk of a possible null pointer dereference.
>
> Was largely found by using a static code analysis program called cppcheck.
>
> Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
> ---
> .../lustre/lustre/obdclass/lprocfs_status.c | 20 +++++++++-----------
> 1 file changed, 9 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c b/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
> index 61e04af..4a7891a 100644
> --- a/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
> +++ b/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
> @@ -1897,17 +1897,15 @@ int lprocfs_write_frac_u64_helper(const char *buffer, unsigned long count,
> }
>
> units = 1;
> - switch (*end) {
> - case 'p': case 'P':
> - units <<= 10;
> - case 't': case 'T':
> - units <<= 10;
> - case 'g': case 'G':
> - units <<= 10;
> - case 'm': case 'M':
> - units <<= 10;
> - case 'k': case 'K':
> - units <<= 10;
> + if (end) {
> + switch (*end) {
> + case 'p': case 'P':
> + case 't': case 'T':
> + case 'g': case 'G':
> + case 'm': case 'M':
> + case 'k': case 'K':
> + units <<= 10;
> + }
You know you just changed the logic in the code, right?
Why? Have you tested this?
greg k-h
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH] staging: lustre: lustre: obdclass: lprocfs_status.c: Fix for possible null pointer dereference
2014-12-14 22:39 ` Greg Kroah-Hartman
@ 2014-12-14 22:43 ` Rickard Strandqvist
0 siblings, 0 replies; 9+ messages in thread
From: Rickard Strandqvist @ 2014-12-14 22:43 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Oleg Drokin, Andreas Dilger, Julia Lawall, Greg Donald,
John L. Hammond, Andriy Skulysh, Fabian Frederick, James Simmons,
HPDD-discuss, devel, linux-kernel@vger.kernel.org
Sorry! extremely stupid. Sending new patch immediately.
Kind regards
Rickard Strandqvist
2014-12-14 23:39 GMT+01:00 Greg Kroah-Hartman <gregkh@linuxfoundation.org>:
> On Sun, Dec 14, 2014 at 11:36:22PM +0100, Rickard Strandqvist wrote:
>> There is otherwise a risk of a possible null pointer dereference.
>>
>> Was largely found by using a static code analysis program called cppcheck.
>>
>> Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
>> ---
>> .../lustre/lustre/obdclass/lprocfs_status.c | 20 +++++++++-----------
>> 1 file changed, 9 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c b/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
>> index 61e04af..4a7891a 100644
>> --- a/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
>> +++ b/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
>> @@ -1897,17 +1897,15 @@ int lprocfs_write_frac_u64_helper(const char *buffer, unsigned long count,
>> }
>>
>> units = 1;
>> - switch (*end) {
>> - case 'p': case 'P':
>> - units <<= 10;
>> - case 't': case 'T':
>> - units <<= 10;
>> - case 'g': case 'G':
>> - units <<= 10;
>> - case 'm': case 'M':
>> - units <<= 10;
>> - case 'k': case 'K':
>> - units <<= 10;
>> + if (end) {
>> + switch (*end) {
>> + case 'p': case 'P':
>> + case 't': case 'T':
>> + case 'g': case 'G':
>> + case 'm': case 'M':
>> + case 'k': case 'K':
>> + units <<= 10;
>> + }
>
> You know you just changed the logic in the code, right?
>
> Why? Have you tested this?
>
> greg k-h
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH] staging: lustre: lustre: obdclass: lprocfs_status.c: Fix for possible null pointer dereference
@ 2014-12-14 22:52 Rickard Strandqvist
2014-12-15 1:51 ` Joe Perches
2014-12-16 4:40 ` Chris Rorvick
0 siblings, 2 replies; 9+ messages in thread
From: Rickard Strandqvist @ 2014-12-14 22:52 UTC (permalink / raw)
To: Oleg Drokin, Andreas Dilger
Cc: Rickard Strandqvist, Greg Kroah-Hartman, Julia Lawall,
Greg Donald, John L. Hammond, Andriy Skulysh, Fabian Frederick,
James Simmons, HPDD-discuss, devel, linux-kernel
There is otherwise a risk of a possible null pointer dereference.
Was largely found by using a static code analysis program called cppcheck.
Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
---
.../lustre/lustre/obdclass/lprocfs_status.c | 24 +++++++++++---------
1 file changed, 13 insertions(+), 11 deletions(-)
diff --git a/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c b/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
index 61e04af..5227324 100644
--- a/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
+++ b/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
@@ -1897,17 +1897,19 @@ int lprocfs_write_frac_u64_helper(const char *buffer, unsigned long count,
}
units = 1;
- switch (*end) {
- case 'p': case 'P':
- units <<= 10;
- case 't': case 'T':
- units <<= 10;
- case 'g': case 'G':
- units <<= 10;
- case 'm': case 'M':
- units <<= 10;
- case 'k': case 'K':
- units <<= 10;
+ if (end) {
+ switch (*end) {
+ case 'p': case 'P':
+ units <<= 10;
+ case 't': case 'T':
+ units <<= 10;
+ case 'g': case 'G':
+ units <<= 10;
+ case 'm': case 'M':
+ units <<= 10;
+ case 'k': case 'K':
+ units <<= 10;
+ }
}
/* Specified units override the multiplier */
if (units)
--
1.7.10.4
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PATCH] staging: lustre: lustre: obdclass: lprocfs_status.c: Fix for possible null pointer dereference
2014-12-14 22:52 Rickard Strandqvist
@ 2014-12-15 1:51 ` Joe Perches
2014-12-15 22:23 ` Rickard Strandqvist
2014-12-16 4:40 ` Chris Rorvick
1 sibling, 1 reply; 9+ messages in thread
From: Joe Perches @ 2014-12-15 1:51 UTC (permalink / raw)
To: Rickard Strandqvist
Cc: Oleg Drokin, Andreas Dilger, Greg Kroah-Hartman, Julia Lawall,
Greg Donald, John L. Hammond, Andriy Skulysh, Fabian Frederick,
James Simmons, HPDD-discuss, devel, linux-kernel
On Sun, 2014-12-14 at 23:52 +0100, Rickard Strandqvist wrote:
> There is otherwise a risk of a possible null pointer dereference.
>
> Was largely found by using a static code analysis program called cppcheck.
Perhaps the tool could use a little work.
It's not possible for end to be NULL no?
unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
{
unsigned long long result;
unsigned int rv;
cp = _parse_integer_fixup_radix(cp, &base);
rv = _parse_integer(cp, base, &result);
/* FIXME */
cp += (rv & ~KSTRTOX_OVERFLOW);
if (endp)
*endp = (char *)cp;
return result;
}
EXPORT_SYMBOL(simple_strtoull);
> diff --git a/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c b/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
[]
Above this:
whole = simple_strtoull(pbuf, &end, 10);
> +++ b/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
> @@ -1897,17 +1897,19 @@ int lprocfs_write_frac_u64_helper(const char *buffer, unsigned long count,
> }
>
> units = 1;
> - switch (*end) {
> - case 'p': case 'P':
> - units <<= 10;
> - case 't': case 'T':
> - units <<= 10;
> - case 'g': case 'G':
> - units <<= 10;
> - case 'm': case 'M':
> - units <<= 10;
> - case 'k': case 'K':
> - units <<= 10;
> + if (end) {
> + switch (*end) {
> + case 'p': case 'P':
> + units <<= 10;
> + case 't': case 'T':
> + units <<= 10;
> + case 'g': case 'G':
> + units <<= 10;
> + case 'm': case 'M':
> + units <<= 10;
> + case 'k': case 'K':
> + units <<= 10;
> + }
The only thing I might do is
switch (tolower(*end)) {
and remove the second case entry for each line
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH] staging: lustre: lustre: obdclass: lprocfs_status.c: Fix for possible null pointer dereference
2014-12-15 1:51 ` Joe Perches
@ 2014-12-15 22:23 ` Rickard Strandqvist
2014-12-15 23:53 ` Joe Perches
2014-12-16 9:27 ` Dan Carpenter
0 siblings, 2 replies; 9+ messages in thread
From: Rickard Strandqvist @ 2014-12-15 22:23 UTC (permalink / raw)
To: Joe Perches
Cc: Oleg Drokin, Andreas Dilger, Greg Kroah-Hartman, Julia Lawall,
Greg Donald, John L. Hammond, Andriy Skulysh, Fabian Frederick,
James Simmons, HPDD-discuss, devel, linux-kernel@vger.kernel.org
Hi Joe
No, it does not look like end can be NULL then.
Then remove the end != NULL instead?
...
if (end != NULL && *end == '.') {
However, I am hesitant to the tolower() I think double case is faster...?
Kind regards
Rickard Strandqvist
2014-12-15 2:51 GMT+01:00 Joe Perches <joe@perches.com>:
> On Sun, 2014-12-14 at 23:52 +0100, Rickard Strandqvist wrote:
>> There is otherwise a risk of a possible null pointer dereference.
>>
>> Was largely found by using a static code analysis program called cppcheck.
>
> Perhaps the tool could use a little work.
> It's not possible for end to be NULL no?
>
> unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
> {
> unsigned long long result;
> unsigned int rv;
>
> cp = _parse_integer_fixup_radix(cp, &base);
> rv = _parse_integer(cp, base, &result);
> /* FIXME */
> cp += (rv & ~KSTRTOX_OVERFLOW);
>
> if (endp)
> *endp = (char *)cp;
>
> return result;
> }
> EXPORT_SYMBOL(simple_strtoull);
>
>
>> diff --git a/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c b/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
> []
>
> Above this:
>
> whole = simple_strtoull(pbuf, &end, 10);
>
>> +++ b/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
>> @@ -1897,17 +1897,19 @@ int lprocfs_write_frac_u64_helper(const char *buffer, unsigned long count,
>> }
>>
>> units = 1;
>> - switch (*end) {
>> - case 'p': case 'P':
>> - units <<= 10;
>> - case 't': case 'T':
>> - units <<= 10;
>> - case 'g': case 'G':
>> - units <<= 10;
>> - case 'm': case 'M':
>> - units <<= 10;
>> - case 'k': case 'K':
>> - units <<= 10;
>> + if (end) {
>> + switch (*end) {
>> + case 'p': case 'P':
>> + units <<= 10;
>> + case 't': case 'T':
>> + units <<= 10;
>> + case 'g': case 'G':
>> + units <<= 10;
>> + case 'm': case 'M':
>> + units <<= 10;
>> + case 'k': case 'K':
>> + units <<= 10;
>> + }
>
> The only thing I might do is
>
> switch (tolower(*end)) {
>
> and remove the second case entry for each line
>
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH] staging: lustre: lustre: obdclass: lprocfs_status.c: Fix for possible null pointer dereference
2014-12-15 22:23 ` Rickard Strandqvist
@ 2014-12-15 23:53 ` Joe Perches
2014-12-16 9:27 ` Dan Carpenter
1 sibling, 0 replies; 9+ messages in thread
From: Joe Perches @ 2014-12-15 23:53 UTC (permalink / raw)
To: Rickard Strandqvist
Cc: Oleg Drokin, Andreas Dilger, Greg Kroah-Hartman, Julia Lawall,
Greg Donald, John L. Hammond, Andriy Skulysh, Fabian Frederick,
James Simmons, HPDD-discuss, devel, linux-kernel@vger.kernel.org
On Mon, 2014-12-15 at 23:23 +0100, Rickard Strandqvist wrote:
> Hi Joe
Hello Rickard
> No, it does not look like end can be NULL then.
> Then remove the end != NULL instead?
> ...
> if (end != NULL && *end == '.') {
Up to you.
> However, I am hesitant to the tolower() I think double case is faster...?
I doubt code execution speed is paramount here.
Maybe see if the object code size is smaller one
way or the other.
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH] staging: lustre: lustre: obdclass: lprocfs_status.c: Fix for possible null pointer dereference
2014-12-15 22:23 ` Rickard Strandqvist
2014-12-15 23:53 ` Joe Perches
@ 2014-12-16 9:27 ` Dan Carpenter
1 sibling, 0 replies; 9+ messages in thread
From: Dan Carpenter @ 2014-12-16 9:27 UTC (permalink / raw)
To: Rickard Strandqvist
Cc: Joe Perches, devel, Fabian Frederick, Andreas Dilger,
Julia Lawall, James Simmons, Greg Kroah-Hartman,
linux-kernel@vger.kernel.org, Oleg Drokin, Greg Donald,
HPDD-discuss, Andriy Skulysh, John L. Hammond
On Mon, Dec 15, 2014 at 11:23:25PM +0100, Rickard Strandqvist wrote:
> Hi Joe
>
> No, it does not look like end can be NULL then.
> Then remove the end != NULL instead?
> ...
> if (end != NULL && *end == '.') {
>
Yes. Please do.
regards,
dan carpenter
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] staging: lustre: lustre: obdclass: lprocfs_status.c: Fix for possible null pointer dereference
2014-12-14 22:52 Rickard Strandqvist
2014-12-15 1:51 ` Joe Perches
@ 2014-12-16 4:40 ` Chris Rorvick
1 sibling, 0 replies; 9+ messages in thread
From: Chris Rorvick @ 2014-12-16 4:40 UTC (permalink / raw)
To: Rickard Strandqvist
Cc: Oleg Drokin, Andreas Dilger, Greg Kroah-Hartman, Julia Lawall,
Greg Donald, John L. Hammond, Andriy Skulysh, Fabian Frederick,
James Simmons, HPDD-discuss, devel, linux-kernel
On Sun, Dec 14, 2014 at 4:52 PM, Rickard Strandqvist
<rickard_strandqvist@spectrumdigital.se> wrote:
> units = 1;
...
> /* Specified units override the multiplier */
> if (units)
That doesn't make much sense. The conditional logic will always be
executed. Maybe this is what's intended?
/* Specified units override the multiplier */
- if (units)
+ if (units > 1)
mult = mult < 0 ? -units : units;
Chris
^ permalink raw reply [flat|nested] 9+ messages in thread
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2014-12-14 22:36 [PATCH] staging: lustre: lustre: obdclass: lprocfs_status.c: Fix for possible null pointer dereference Rickard Strandqvist
2014-12-14 22:39 ` Greg Kroah-Hartman
2014-12-14 22:43 ` Rickard Strandqvist
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2014-12-14 22:52 Rickard Strandqvist
2014-12-15 1:51 ` Joe Perches
2014-12-15 22:23 ` Rickard Strandqvist
2014-12-15 23:53 ` Joe Perches
2014-12-16 9:27 ` Dan Carpenter
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