[Tarantool-patches] [PATCH luajit] Limit path length passed to C library loader.

[Tarantool-patches] [PATCH luajit] Limit path length passed to C library loader.

[Maksim Kokryashkin via Tarantool-patches]

From: Mike Pall <mike>

(cherry-picked from commit 90e65514dda3994253c1e3007f63da7ace8f6b7b)

C library loader uses `dlopen` under the hood, which fails, if
provided library path is longer than PATH_MAX. PATH_MAX is
4096 bytes by default, so a corresponsing check is added to
`ll_loadfunc`.

Maxim Kokryashkin:
* added the description and the test for the problem

Part of tarantool/tarantool#8069
---
Side note: Still no adequate constants like PATH_MAX...
Side note: There is no test for successfull loadlib, since
there is one in the PUC-Rio suite.

Branch: https://github.com/tarantool/luajit/tree/fckxorg/c-library-path-length
PR: https://github.com/tarantool/tarantool/pull/8449

 src/lib_package.c                                   |  7 ++++++-
 test/tarantool-tests/c-library-path-length.test.lua | 13 +++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)
 create mode 100644 test/tarantool-tests/c-library-path-length.test.lua

diff --git a/src/lib_package.c b/src/lib_package.c
index 8573b9f9..67959a10 100644
--- a/src/lib_package.c
+++ b/src/lib_package.c
@@ -215,7 +215,12 @@ static const char *mksymname(lua_State *L, const char *modname,
 
 static int ll_loadfunc(lua_State *L, const char *path, const char *name, int r)
 {
-  void **reg = ll_register(L, path);
+  void **reg;
+  if (strlen(path) >= 4096) {
+    lua_pushliteral(L, "path too long");
+    return PACKAGE_ERR_LIB;
+  }
+  reg = ll_register(L, path);
   if (*reg == NULL) *reg = ll_load(L, path, (*name == '*'));
   if (*reg == NULL) {
     return PACKAGE_ERR_LIB;  /* Unable to load library. */
diff --git a/test/tarantool-tests/c-library-path-length.test.lua b/test/tarantool-tests/c-library-path-length.test.lua
new file mode 100644
index 00000000..11dd0cf4
--- /dev/null
+++ b/test/tarantool-tests/c-library-path-length.test.lua
@@ -0,0 +1,13 @@
+local tap = require('tap')
+local test = tap.test('c-library-path-length')
+test:plan(2)
+
+-- It doesn't really matter how long that string is, if it is longer than 4096.
+local long_path = string.rep('/path', 1024)
+package.cpath = long_path
+
+local res, err = package.loadlib(long_path, 'func')
+test:ok(res == nil, 'loaded library with a too large path')
+test:like(err, 'path too long', 'incorrect error')
+
+os.exit(test:check() and 0 or 1)
-- 
2.37.1 (Apple Git-137.1)

Re: [Tarantool-patches] [PATCH luajit] Limit path length passed to C library loader.

[Sergey Kaplun via Tarantool-patches]

Hi, Maksim!
Thanks for the patch!
LGTM, except a few minor nits regarding the commit message and the
comment.

On 16.03.23, Maksim Kokryashkin wrote:
> From: Mike Pall <mike>
> 
> (cherry-picked from commit 90e65514dda3994253c1e3007f63da7ace8f6b7b)
> 
> C library loader uses `dlopen` under the hood, which fails, if

Typo: s/C library loader/The C library loader/

> provided library path is longer than PATH_MAX. PATH_MAX is
> 4096 bytes by default, so a corresponsing check is added to

Typo: s/corresponsing/corresponding/

> `ll_loadfunc`.
> 
> Maxim Kokryashkin:
> * added the description and the test for the problem
> 
> Part of tarantool/tarantool#8069
> ---
> Side note: Still no adequate constants like PATH_MAX...
> Side note: There is no test for successfull loadlib, since
> there is one in the PUC-Rio suite.
> 
> Branch: https://github.com/tarantool/luajit/tree/fckxorg/c-library-path-length
> PR: https://github.com/tarantool/tarantool/pull/8449
> 
>  src/lib_package.c                                   |  7 ++++++-
>  test/tarantool-tests/c-library-path-length.test.lua | 13 +++++++++++++
>  2 files changed, 19 insertions(+), 1 deletion(-)
>  create mode 100644 test/tarantool-tests/c-library-path-length.test.lua
> 
> diff --git a/src/lib_package.c b/src/lib_package.c
> index 8573b9f9..67959a10 100644
> --- a/src/lib_package.c
> +++ b/src/lib_package.c
> @@ -215,7 +215,12 @@ static const char *mksymname(lua_State *L, const char *modname,
>  
>  static int ll_loadfunc(lua_State *L, const char *path, const char *name, int r)
>  {
> -  void **reg = ll_register(L, path);
> +  void **reg;
> +  if (strlen(path) >= 4096) {

Side note: Why don't just use PATH_MAX here? AFAIK, it may be less than
4096 bytes. Just complaining.

> +    lua_pushliteral(L, "path too long");
> +    return PACKAGE_ERR_LIB;
> +  }
> +  reg = ll_register(L, path);
>    if (*reg == NULL) *reg = ll_load(L, path, (*name == '*'));
>    if (*reg == NULL) {
>      return PACKAGE_ERR_LIB;  /* Unable to load library. */
> diff --git a/test/tarantool-tests/c-library-path-length.test.lua b/test/tarantool-tests/c-library-path-length.test.lua
> new file mode 100644
> index 00000000..11dd0cf4
> --- /dev/null
> +++ b/test/tarantool-tests/c-library-path-length.test.lua
> @@ -0,0 +1,13 @@
> +local tap = require('tap')
> +local test = tap.test('c-library-path-length')
> +test:plan(2)
> +
> +-- It doesn't really matter how long that string is, if it is longer than 4096.

Minor: comment line is longer than 66 symbols.

> +local long_path = string.rep('/path', 1024)
> +package.cpath = long_path
> +
> +local res, err = package.loadlib(long_path, 'func')
> +test:ok(res == nil, 'loaded library with a too large path')
> +test:like(err, 'path too long', 'incorrect error')
> +
> +os.exit(test:check() and 0 or 1)
> -- 
> 2.37.1 (Apple Git-137.1)
> 

-- 
Best regards,
Sergey Kaplun

Re: [Tarantool-patches] [PATCH luajit] Limit path length passed to C library loader.

[Maxim Kokryashkin via Tarantool-patches]

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Hi, Sergey!
Thanks for the review!
Fixed nits you mentioned, the branch is force-pushed.
--
Best regards,
Maxim Kokryashkin
 
  
>Пятница, 17 марта 2023, 14:21 +03:00 от Sergey Kaplun <skaplun@tarantool.org>:
> 
>Hi, Maksim!
>Thanks for the patch!
>LGTM, except a few minor nits regarding the commit message and the
>comment.
>
>On 16.03.23, Maksim Kokryashkin wrote:
>> From: Mike Pall <mike>
>>
>> (cherry-picked from commit 90e65514dda3994253c1e3007f63da7ace8f6b7b)
>>
>> C library loader uses `dlopen` under the hood, which fails, if
>
>Typo: s/C library loader/The C library loader/
>
>> provided library path is longer than PATH_MAX. PATH_MAX is
>> 4096 bytes by default, so a corresponsing check is added to
>
>Typo: s/corresponsing/corresponding/
>
>> `ll_loadfunc`.
>>
>> Maxim Kokryashkin:
>> * added the description and the test for the problem
>>
>> Part of tarantool/tarantool#8069
>> ---
>> Side note: Still no adequate constants like PATH_MAX...
>> Side note: There is no test for successfull loadlib, since
>> there is one in the PUC-Rio suite.
>>
>> Branch:  https://github.com/tarantool/luajit/tree/fckxorg/c-library-path-length
>> PR:  https://github.com/tarantool/tarantool/pull/8449
>>
>> src/lib_package.c | 7 ++++++-
>> test/tarantool-tests/c-library-path-length.test.lua | 13 +++++++++++++
>> 2 files changed, 19 insertions(+), 1 deletion(-)
>> create mode 100644 test/tarantool-tests/c-library-path-length.test.lua
>>
>> diff --git a/src/lib_package.c b/src/lib_package.c
>> index 8573b9f9..67959a10 100644
>> --- a/src/lib_package.c
>> +++ b/src/lib_package.c
>> @@ -215,7 +215,12 @@ static const char *mksymname(lua_State *L, const char *modname,
>>
>> static int ll_loadfunc(lua_State *L, const char *path, const char *name, int r)
>> {
>> - void **reg = ll_register(L, path);
>> + void **reg;
>> + if (strlen(path) >= 4096) {
>
>Side note: Why don't just use PATH_MAX here? AFAIK, it may be less than
>4096 bytes. Just complaining.
>
>> + lua_pushliteral(L, "path too long");
>> + return PACKAGE_ERR_LIB;
>> + }
>> + reg = ll_register(L, path);
>> if (*reg == NULL) *reg = ll_load(L, path, (*name == '*'));
>> if (*reg == NULL) {
>> return PACKAGE_ERR_LIB; /* Unable to load library. */
>> diff --git a/test/tarantool-tests/c-library-path-length.test.lua b/test/tarantool-tests/c-library-path-length.test.lua
>> new file mode 100644
>> index 00000000..11dd0cf4
>> --- /dev/null
>> +++ b/test/tarantool-tests/c-library-path-length.test.lua
>> @@ -0,0 +1,13 @@
>> +local tap = require('tap')
>> +local test = tap.test('c-library-path-length')
>> +test:plan(2)
>> +
>> +-- It doesn't really matter how long that string is, if it is longer than 4096.
>
>Minor: comment line is longer than 66 symbols.
>
>> +local long_path = string.rep('/path', 1024)
>> +package.cpath = long_path
>> +
>> +local res, err = package.loadlib(long_path, 'func')
>> +test:ok(res == nil, 'loaded library with a too large path')
>> +test:like(err, 'path too long', 'incorrect error')
>> +
>> +os.exit(test:check() and 0 or 1)
>> --
>> 2.37.1 (Apple Git-137.1)
>>
>
>--
>Best regards,
>Sergey Kaplun
 

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Re: [Tarantool-patches] [PATCH luajit] Limit path length passed to C library loader.

[Igor Munkin via Tarantool-patches]

Max,

Thanks for the patch! LGTM, considering the fixes for Sergey comments.

On 16.03.23, Maksim Kokryashkin via Tarantool-patches wrote:
> From: Mike Pall <mike>
> 
> (cherry-picked from commit 90e65514dda3994253c1e3007f63da7ace8f6b7b)
> 
> C library loader uses `dlopen` under the hood, which fails, if
> provided library path is longer than PATH_MAX. PATH_MAX is
> 4096 bytes by default, so a corresponsing check is added to
> `ll_loadfunc`.
> 
> Maxim Kokryashkin:
> * added the description and the test for the problem
> 
> Part of tarantool/tarantool#8069
> ---
> Side note: Still no adequate constants like PATH_MAX...
> Side note: There is no test for successfull loadlib, since
> there is one in the PUC-Rio suite.
> 
> Branch: https://github.com/tarantool/luajit/tree/fckxorg/c-library-path-length
> PR: https://github.com/tarantool/tarantool/pull/8449
> 
>  src/lib_package.c                                   |  7 ++++++-
>  test/tarantool-tests/c-library-path-length.test.lua | 13 +++++++++++++
>  2 files changed, 19 insertions(+), 1 deletion(-)
>  create mode 100644 test/tarantool-tests/c-library-path-length.test.lua
> 

<snipped>

> -- 
> 2.37.1 (Apple Git-137.1)
> 

-- 
Best regards,
IM

Re: [Tarantool-patches] [PATCH luajit] Limit path length passed to C library loader.

[Igor Munkin via Tarantool-patches]

Max,

I've checked the patchset into all long-term branches in
tarantool/luajit and bumped a new version in master, 2.11 and 2.10.

On 16.03.23, Maksim Kokryashkin via Tarantool-patches wrote:
> From: Mike Pall <mike>
> 
> (cherry-picked from commit 90e65514dda3994253c1e3007f63da7ace8f6b7b)
> 
> C library loader uses `dlopen` under the hood, which fails, if
> provided library path is longer than PATH_MAX. PATH_MAX is
> 4096 bytes by default, so a corresponsing check is added to
> `ll_loadfunc`.
> 
> Maxim Kokryashkin:
> * added the description and the test for the problem
> 
> Part of tarantool/tarantool#8069
> ---
> Side note: Still no adequate constants like PATH_MAX...
> Side note: There is no test for successfull loadlib, since
> there is one in the PUC-Rio suite.
> 
> Branch: https://github.com/tarantool/luajit/tree/fckxorg/c-library-path-length
> PR: https://github.com/tarantool/tarantool/pull/8449
> 
>  src/lib_package.c                                   |  7 ++++++-
>  test/tarantool-tests/c-library-path-length.test.lua | 13 +++++++++++++
>  2 files changed, 19 insertions(+), 1 deletion(-)
>  create mode 100644 test/tarantool-tests/c-library-path-length.test.lua
> 

<snipped>

> -- 
> 2.37.1 (Apple Git-137.1)
> 

-- 
Best regards,
IM