diff mbox series

[V9fs-developer] version pointer uninitialized

Message ID 20180709222943.19503-1-tomasbortoli@gmail.com
State Not Applicable, archived
Delegated to: David Miller
Headers show
Series [V9fs-developer] version pointer uninitialized | expand

Commit Message

Tomas Bortoli July 9, 2018, 10:29 p.m. UTC
The p9_client_version() does not initialize the version
pointer. If the call to p9pdu_readf() returns an error and version has not
been allocated in p9pdu_readf(), then the program will jump to the "error"
label and will try to free the version pointer. If version is not
initialized, free() will be called with uninitialized, garbage data and
will provoke a crash.

Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com>
Reported-by: syzbot+65c6b72f284a39d416b4@syzkaller.appspotmail.com
---
 net/9p/client.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

piaojun July 10, 2018, 1:02 a.m. UTC | #1
LGTM

On 2018/7/10 6:29, Tomas Bortoli wrote:
> The p9_client_version() does not initialize the version
> pointer. If the call to p9pdu_readf() returns an error and version has not
> been allocated in p9pdu_readf(), then the program will jump to the "error"
> label and will try to free the version pointer. If version is not
> initialized, free() will be called with uninitialized, garbage data and
> will provoke a crash.
> 
> Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com>
> Reported-by: syzbot+65c6b72f284a39d416b4@syzkaller.appspotmail.com
Reviewed-by: Jun Piao <piaojun@huawei.com>
> ---
>  net/9p/client.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/9p/client.c b/net/9p/client.c
> index 18c5271910dc..40f7c47f2f74 100644
> --- a/net/9p/client.c
> +++ b/net/9p/client.c
> @@ -957,7 +957,7 @@ static int p9_client_version(struct p9_client *c)
>  {
>  	int err = 0;
>  	struct p9_req_t *req;
> -	char *version;
> +	char *version = NULL;
>  	int msize;
>  
>  	p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
>
jiangyiwen July 11, 2018, 1:26 a.m. UTC | #2
On 2018/7/10 6:29, Tomas Bortoli wrote:
> The p9_client_version() does not initialize the version
> pointer. If the call to p9pdu_readf() returns an error and version has not
> been allocated in p9pdu_readf(), then the program will jump to the "error"
> label and will try to free the version pointer. If version is not
> initialized, free() will be called with uninitialized, garbage data and
> will provoke a crash.
> 
> Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com>

Reviewed-by: Yiwen Jiang <jiangyiwen@huawei.com>

> Reported-by: syzbot+65c6b72f284a39d416b4@syzkaller.appspotmail.com
> ---
>  net/9p/client.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/9p/client.c b/net/9p/client.c
> index 18c5271910dc..40f7c47f2f74 100644
> --- a/net/9p/client.c
> +++ b/net/9p/client.c
> @@ -957,7 +957,7 @@ static int p9_client_version(struct p9_client *c)
>  {
>  	int err = 0;
>  	struct p9_req_t *req;
> -	char *version;
> +	char *version = NULL;
>  	int msize;
>  
>  	p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
>
Tomas Bortoli July 12, 2018, 4:44 p.m. UTC | #3
On 07/11/2018 03:26 AM, jiangyiwen wrote:
> On 2018/7/10 6:29, Tomas Bortoli wrote:
>> The p9_client_version() does not initialize the version
>> pointer. If the call to p9pdu_readf() returns an error and version has not
>> been allocated in p9pdu_readf(), then the program will jump to the "error"
>> label and will try to free the version pointer. If version is not
>> initialized, free() will be called with uninitialized, garbage data and
>> will provoke a crash.
>>
>> Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com>
> Reviewed-by: Yiwen Jiang <jiangyiwen@huawei.com>
>
>> Reported-by: syzbot+65c6b72f284a39d416b4@syzkaller.appspotmail.com
>> ---
>>  net/9p/client.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/net/9p/client.c b/net/9p/client.c
>> index 18c5271910dc..40f7c47f2f74 100644
>> --- a/net/9p/client.c
>> +++ b/net/9p/client.c
>> @@ -957,7 +957,7 @@ static int p9_client_version(struct p9_client *c)
>>  {
>>  	int err = 0;
>>  	struct p9_req_t *req;
>> -	char *version;
>> +	char *version = NULL;
>>  	int msize;
>>  
>>  	p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
>>
>

+ Cc: Andrew Morton <akpm@linux-foundation.org>

This goes with the other patch: [V9fs-developer] [PATCH]
p9_parse_header() validate PDU length

Tomas
diff mbox series

Patch

diff --git a/net/9p/client.c b/net/9p/client.c
index 18c5271910dc..40f7c47f2f74 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -957,7 +957,7 @@  static int p9_client_version(struct p9_client *c)
 {
 	int err = 0;
 	struct p9_req_t *req;
-	char *version;
+	char *version = NULL;
 	int msize;
 
 	p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",