[v2] Linux: Fix UTC offset setting in settimeofday for __TIMESIZE != 64

Message ID 87lfk4mlz6.fsf@oldenburg2.str.redhat.com
State New
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Series
  • [v2] Linux: Fix UTC offset setting in settimeofday for __TIMESIZE != 64
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Commit Message

Adhemerval Zanella via Libc-alpha June 30, 2020, 6:45 p.m.
The time argument is NULL in this case, and attempt to convert it
leads to a null pointer dereference.

This fixes commit d2e3b697da2433c08702f95c76458c51545c3df1
("y2038: linux: Provide __settimeofday64 implementation").

---
v2: Add just a null pointer check.  Tested on x86_64-linux-gnu and
    i686-linux-gnu.

 sysdeps/unix/sysv/linux/settimeofday.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

Comments

Adhemerval Zanella via Libc-alpha June 30, 2020, 7:12 p.m. | #1
On 30/06/2020 15:45, Florian Weimer wrote:
> The time argument is NULL in this case, and attempt to convert it

> leads to a null pointer dereference.

> 

> This fixes commit d2e3b697da2433c08702f95c76458c51545c3df1

> ("y2038: linux: Provide __settimeofday64 implementation").


LGTM, thanks.

Reviwed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> 

> ---

> v2: Add just a null pointer check.  Tested on x86_64-linux-gnu and

>     i686-linux-gnu.

> 

>  sysdeps/unix/sysv/linux/settimeofday.c | 11 ++++++++---

>  1 file changed, 8 insertions(+), 3 deletions(-)

> 

> diff --git a/sysdeps/unix/sysv/linux/settimeofday.c b/sysdeps/unix/sysv/linux/settimeofday.c

> index ea45f1d7cb..6f4bc7ef3c 100644

> --- a/sysdeps/unix/sysv/linux/settimeofday.c

> +++ b/sysdeps/unix/sysv/linux/settimeofday.c

> @@ -25,6 +25,7 @@

>  int

>  __settimeofday64 (const struct __timeval64 *tv, const struct timezone *tz)

>  {

> +  /* Backwards compatibility for setting the UTC offset.  */

>    if (__glibc_unlikely (tz != 0))

>      {

>        if (tv != 0)

> @@ -45,9 +46,13 @@ libc_hidden_def (__settimeofday64)

>  int

>  __settimeofday (const struct timeval *tv, const struct timezone *tz)

>  {

> -  struct __timeval64 tv64 = valid_timeval_to_timeval64 (*tv);

> -

> -  return __settimeofday64 (&tv64, tz);

> +  if (__glibc_unlikely (tv == NULL))

> +      return __settimeofday64 (NULL, tz);


Indentation seems off here.

> +  else

> +    {

> +      struct __timeval64 tv64 = valid_timeval_to_timeval64 (*tv);

> +      return __settimeofday64 (&tv64, tz);

> +    }

>  }

>  #endif

>  weak_alias (__settimeofday, settimeofday);

>
Adhemerval Zanella via Libc-alpha June 30, 2020, 7:19 p.m. | #2
* Adhemerval Zanella:

> On 30/06/2020 15:45, Florian Weimer wrote:

>> The time argument is NULL in this case, and attempt to convert it

>> leads to a null pointer dereference.

>> 

>> This fixes commit d2e3b697da2433c08702f95c76458c51545c3df1

>> ("y2038: linux: Provide __settimeofday64 implementation").

>

> LGTM, thanks.

>

> Reviwed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

>

>> 

>> ---

>> v2: Add just a null pointer check.  Tested on x86_64-linux-gnu and

>>     i686-linux-gnu.

>> 

>>  sysdeps/unix/sysv/linux/settimeofday.c | 11 ++++++++---

>>  1 file changed, 8 insertions(+), 3 deletions(-)

>> 

>> diff --git a/sysdeps/unix/sysv/linux/settimeofday.c b/sysdeps/unix/sysv/linux/settimeofday.c

>> index ea45f1d7cb..6f4bc7ef3c 100644

>> --- a/sysdeps/unix/sysv/linux/settimeofday.c

>> +++ b/sysdeps/unix/sysv/linux/settimeofday.c

>> @@ -25,6 +25,7 @@

>>  int

>>  __settimeofday64 (const struct __timeval64 *tv, const struct timezone *tz)

>>  {

>> +  /* Backwards compatibility for setting the UTC offset.  */

>>    if (__glibc_unlikely (tz != 0))

>>      {

>>        if (tv != 0)

>> @@ -45,9 +46,13 @@ libc_hidden_def (__settimeofday64)

>>  int

>>  __settimeofday (const struct timeval *tv, const struct timezone *tz)

>>  {

>> -  struct __timeval64 tv64 = valid_timeval_to_timeval64 (*tv);

>> -

>> -  return __settimeofday64 (&tv64, tz);

>> +  if (__glibc_unlikely (tv == NULL))

>> +      return __settimeofday64 (NULL, tz);

>

> Indentation seems off here.


Thanks.  I'm going to fix this before committing.

Thanks,
Florian
Adhemerval Zanella via Libc-alpha June 30, 2020, 9:07 p.m. | #3
On Tue, Jun 30, 2020 at 11:45 AM Florian Weimer via Libc-alpha
<libc-alpha@sourceware.org> wrote:
>

> The time argument is NULL in this case, and attempt to convert it

> leads to a null pointer dereference.

>

> This fixes commit d2e3b697da2433c08702f95c76458c51545c3df1

> ("y2038: linux: Provide __settimeofday64 implementation").

>

> ---

> v2: Add just a null pointer check.  Tested on x86_64-linux-gnu and

>     i686-linux-gnu.

>

>  sysdeps/unix/sysv/linux/settimeofday.c | 11 ++++++++---

>  1 file changed, 8 insertions(+), 3 deletions(-)

>

> diff --git a/sysdeps/unix/sysv/linux/settimeofday.c b/sysdeps/unix/sysv/linux/settimeofday.c

> index ea45f1d7cb..6f4bc7ef3c 100644

> --- a/sysdeps/unix/sysv/linux/settimeofday.c

> +++ b/sysdeps/unix/sysv/linux/settimeofday.c

> @@ -25,6 +25,7 @@

>  int

>  __settimeofday64 (const struct __timeval64 *tv, const struct timezone *tz)

>  {

> +  /* Backwards compatibility for setting the UTC offset.  */

>    if (__glibc_unlikely (tz != 0))

>      {

>        if (tv != 0)

> @@ -45,9 +46,13 @@ libc_hidden_def (__settimeofday64)

>  int

>  __settimeofday (const struct timeval *tv, const struct timezone *tz)

>  {

> -  struct __timeval64 tv64 = valid_timeval_to_timeval64 (*tv);

> -

> -  return __settimeofday64 (&tv64, tz);

> +  if (__glibc_unlikely (tv == NULL))

> +      return __settimeofday64 (NULL, tz);

> +  else

> +    {

> +      struct __timeval64 tv64 = valid_timeval_to_timeval64 (*tv);

> +      return __settimeofday64 (&tv64, tz);

> +    }


Looks good

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>


Alistair

>  }

>  #endif

>  weak_alias (__settimeofday, settimeofday);

>
Lukasz Majewski July 1, 2020, 12:06 a.m. | #4
On Tue, 30 Jun 2020 20:45:17 +0200
Florian Weimer <fweimer@redhat.com> wrote:

> The time argument is NULL in this case, and attempt to convert it

> leads to a null pointer dereference.

> 

> This fixes commit d2e3b697da2433c08702f95c76458c51545c3df1

> ("y2038: linux: Provide __settimeofday64 implementation").

> 

> ---

> v2: Add just a null pointer check.  Tested on x86_64-linux-gnu and

>     i686-linux-gnu.

> 

>  sysdeps/unix/sysv/linux/settimeofday.c | 11 ++++++++---

>  1 file changed, 8 insertions(+), 3 deletions(-)

> 

> diff --git a/sysdeps/unix/sysv/linux/settimeofday.c

> b/sysdeps/unix/sysv/linux/settimeofday.c index ea45f1d7cb..6f4bc7ef3c

> 100644 --- a/sysdeps/unix/sysv/linux/settimeofday.c

> +++ b/sysdeps/unix/sysv/linux/settimeofday.c

> @@ -25,6 +25,7 @@

>  int

>  __settimeofday64 (const struct __timeval64 *tv, const struct

> timezone *tz) {

> +  /* Backwards compatibility for setting the UTC offset.  */

>    if (__glibc_unlikely (tz != 0))

>      {

>        if (tv != 0)

> @@ -45,9 +46,13 @@ libc_hidden_def (__settimeofday64)

>  int

>  __settimeofday (const struct timeval *tv, const struct timezone *tz)

>  {

> -  struct __timeval64 tv64 = valid_timeval_to_timeval64 (*tv);

> -

> -  return __settimeofday64 (&tv64, tz);

> +  if (__glibc_unlikely (tv == NULL))

> +      return __settimeofday64 (NULL, tz);

> +  else

> +    {

> +      struct __timeval64 tv64 = valid_timeval_to_timeval64 (*tv);

> +      return __settimeofday64 (&tv64, tz);

> +    }

>  }

>  #endif

>  weak_alias (__settimeofday, settimeofday);

> 


Reviewed-by: Lukasz Majewski <lukma@denx.de>



Best regards,

Lukasz Majewski

--

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de

Patch

diff --git a/sysdeps/unix/sysv/linux/settimeofday.c b/sysdeps/unix/sysv/linux/settimeofday.c
index ea45f1d7cb..6f4bc7ef3c 100644
--- a/sysdeps/unix/sysv/linux/settimeofday.c
+++ b/sysdeps/unix/sysv/linux/settimeofday.c
@@ -25,6 +25,7 @@ 
 int
 __settimeofday64 (const struct __timeval64 *tv, const struct timezone *tz)
 {
+  /* Backwards compatibility for setting the UTC offset.  */
   if (__glibc_unlikely (tz != 0))
     {
       if (tv != 0)
@@ -45,9 +46,13 @@  libc_hidden_def (__settimeofday64)
 int
 __settimeofday (const struct timeval *tv, const struct timezone *tz)
 {
-  struct __timeval64 tv64 = valid_timeval_to_timeval64 (*tv);
-
-  return __settimeofday64 (&tv64, tz);
+  if (__glibc_unlikely (tv == NULL))
+      return __settimeofday64 (NULL, tz);
+  else
+    {
+      struct __timeval64 tv64 = valid_timeval_to_timeval64 (*tv);
+      return __settimeofday64 (&tv64, tz);
+    }
 }
 #endif
 weak_alias (__settimeofday, settimeofday);