2021-01-05 02:37:53

by Qinglang Miao

Subject: [PATCH] net: qrtr: fix null-ptr-deref in qrtr_ns_remove

A null-ptr-deref bug is reported by Hulk Robot like this:
--------------
KASAN: null-ptr-deref in range [0x0000000000000128-0x000000000000012f]
Call Trace:
qrtr_ns_remove+0x22/0x40 [ns]
qrtr_proto_fini+0xa/0x31 [qrtr]
__x64_sys_delete_module+0x337/0x4e0
do_syscall_64+0x34/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x468ded
--------------

When qrtr_ns_init fails in qrtr_proto_init, qrtr_ns_remove which would
be called later on would raise a null-ptr-deref because qrtr_ns.workqueue
has been destroyed.

Fix it by making qrtr_ns_init have a return value and adding a check in
qrtr_proto_init.

Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Qinglang Miao <[email protected]>
---
net/qrtr/ns.c | 7 ++++---
net/qrtr/qrtr.c | 14 +++++++++++---
net/qrtr/qrtr.h | 2 +-
3 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/net/qrtr/ns.c b/net/qrtr/ns.c
index 56aaf8cb6..8d00dfe81 100644
--- a/net/qrtr/ns.c
+++ b/net/qrtr/ns.c
@@ -755,7 +755,7 @@ static void qrtr_ns_data_ready(struct sock *sk)
queue_work(qrtr_ns.workqueue, &qrtr_ns.work);
}

-void qrtr_ns_init(void)
+int qrtr_ns_init(void)
{
struct sockaddr_qrtr sq;
int ret;
@@ -766,7 +766,7 @@ void qrtr_ns_init(void)
ret = sock_create_kern(&init_net, AF_QIPCRTR, SOCK_DGRAM,
PF_QIPCRTR, &qrtr_ns.sock);
if (ret < 0)
- return;
+ return ret;

ret = kernel_getsockname(qrtr_ns.sock, (struct sockaddr *)&sq);
if (ret < 0) {
@@ -797,12 +797,13 @@ void qrtr_ns_init(void)
if (ret < 0)
goto err_wq;

- return;
+ return 0;

err_wq:
destroy_workqueue(qrtr_ns.workqueue);
err_sock:
sock_release(qrtr_ns.sock);
+ return ret;
}
EXPORT_SYMBOL_GPL(qrtr_ns_init);

diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c
index f4ab3ca6d..95533e451 100644
--- a/net/qrtr/qrtr.c
+++ b/net/qrtr/qrtr.c
@@ -1288,12 +1288,20 @@ static int __init qrtr_proto_init(void)

rc = sock_register(&qrtr_family);
if (rc) {
- proto_unregister(&qrtr_proto);
- return rc;
+ goto err_proto;
}

- qrtr_ns_init();
+ rc = qrtr_ns_init();
+ if (rc) {
+ goto err_sock;
+ }

+ return 0;
+
+err_sock:
+ sock_unregister(qrtr_family.family);
+err_proto:
+ proto_unregister(&qrtr_proto);
return rc;
}
postcore_initcall(qrtr_proto_init);
diff --git a/net/qrtr/qrtr.h b/net/qrtr/qrtr.h
index dc2b67f17..3f2d28696 100644
--- a/net/qrtr/qrtr.h
+++ b/net/qrtr/qrtr.h
@@ -29,7 +29,7 @@ void qrtr_endpoint_unregister(struct qrtr_endpoint *ep);

int qrtr_endpoint_post(struct qrtr_endpoint *ep, const void *data, size_t len);

-void qrtr_ns_init(void);
+int qrtr_ns_init(void);

void qrtr_ns_remove(void);

--
2.23.0

2021-01-05 03:30:31

by Wei Yongjun

Subject: Re: [PATCH] net: qrtr: fix null-ptr-deref in qrtr_ns_remove

> A null-ptr-deref bug is reported by Hulk Robot like this:
> --------------
> KASAN: null-ptr-deref in range [0x0000000000000128-0x000000000000012f]
> Call Trace:
> qrtr_ns_remove+0x22/0x40 [ns]
> qrtr_proto_fini+0xa/0x31 [qrtr]
> __x64_sys_delete_module+0x337/0x4e0
> do_syscall_64+0x34/0x80
> entry_SYSCALL_64_after_hwframe+0x44/0xa9
> RIP: 0033:0x468ded
> --------------
>
> When qrtr_ns_init fails in qrtr_proto_init, qrtr_ns_remove which would
> be called later on would raise a null-ptr-deref because qrtr_ns.workqueue
> has been destroyed.
>
> Fix it by making qrtr_ns_init have a return value and adding a check in
> qrtr_proto_init.
>
> Reported-by: Hulk Robot <[email protected]>
> Signed-off-by: Qinglang Miao <[email protected]>
> ---
> net/qrtr/ns.c | 7 ++++---
> net/qrtr/qrtr.c | 14 +++++++++++---
> net/qrtr/qrtr.h | 2 +-
> 3 files changed, 16 insertions(+), 7 deletions(-)
>
> diff --git a/net/qrtr/ns.c b/net/qrtr/ns.c
> index 56aaf8cb6..8d00dfe81 100644
> --- a/net/qrtr/ns.c
> +++ b/net/qrtr/ns.c
> @@ -755,7 +755,7 @@ static void qrtr_ns_data_ready(struct sock *sk)
> queue_work(qrtr_ns.workqueue, &qrtr_ns.work);
> }
>
> -void qrtr_ns_init(void)
> +int qrtr_ns_init(void)
> {
> struct sockaddr_qrtr sq;
> int ret;
> @@ -766,7 +766,7 @@ void qrtr_ns_init(void)
> ret = sock_create_kern(&init_net, AF_QIPCRTR, SOCK_DGRAM,
> PF_QIPCRTR, &qrtr_ns.sock);
> if (ret < 0)
> - return;
> + return ret;
>
> ret = kernel_getsockname(qrtr_ns.sock, (struct sockaddr *)&sq);
> if (ret < 0) {
> @@ -797,12 +797,13 @@ void qrtr_ns_init(void)
> if (ret < 0)
> goto err_wq;
>
> - return;
> + return 0;
>
> err_wq:
> destroy_workqueue(qrtr_ns.workqueue);
> err_sock:
> sock_release(qrtr_ns.sock);
> + return ret;
> }
> EXPORT_SYMBOL_GPL(qrtr_ns_init);
>
> diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c
> index f4ab3ca6d..95533e451 100644
> --- a/net/qrtr/qrtr.c
> +++ b/net/qrtr/qrtr.c
> @@ -1288,12 +1288,20 @@ static int __init qrtr_proto_init(void)
>
> rc = sock_register(&qrtr_family);
> if (rc) {
> - proto_unregister(&qrtr_proto);
> - return rc;
> + goto err_proto;
> }
>


braces {} are not necessary for single statement.


> - qrtr_ns_init();
> + rc = qrtr_ns_init();
> + if (rc) {
> + goto err_sock;
> + }
>
> + return 0;
> +
> +err_sock:
> + sock_unregister(qrtr_family.family);
> +err_proto:
> + proto_unregister(&qrtr_proto);
> return rc;
> }
> postcore_initcall(qrtr_proto_init);
> diff --git a/net/qrtr/qrtr.h b/net/qrtr/qrtr.h
> index dc2b67f17..3f2d28696 100644
> --- a/net/qrtr/qrtr.h
> +++ b/net/qrtr/qrtr.h
> @@ -29,7 +29,7 @@ void qrtr_endpoint_unregister(struct qrtr_endpoint *ep);
>
> int qrtr_endpoint_post(struct qrtr_endpoint *ep, const void *data, size_t len);
>
> -void qrtr_ns_init(void);
> +int qrtr_ns_init(void);
>
> void qrtr_ns_remove(void);
>

2021-01-05 05:56:54

by Qinglang Miao

Subject: Re: [PATCH] net: qrtr: fix null-ptr-deref in qrtr_ns_remove

I sent a v2 on this one because of the redundant braces in
qrtr_proto_init, sorry for the noise.

?? 2021/1/5 10:40, Qinglang Miao д??:
> A null-ptr-deref bug is reported by Hulk Robot like this:
> --------------
> KASAN: null-ptr-deref in range [0x0000000000000128-0x000000000000012f]
> Call Trace:
> qrtr_ns_remove+0x22/0x40 [ns]
> qrtr_proto_fini+0xa/0x31 [qrtr]
> __x64_sys_delete_module+0x337/0x4e0
> do_syscall_64+0x34/0x80
> entry_SYSCALL_64_after_hwframe+0x44/0xa9
> RIP: 0033:0x468ded
> --------------
>
> When qrtr_ns_init fails in qrtr_proto_init, qrtr_ns_remove which would
> be called later on would raise a null-ptr-deref because qrtr_ns.workqueue
> has been destroyed.
>
> Fix it by making qrtr_ns_init have a return value and adding a check in
> qrtr_proto_init.
>
> Reported-by: Hulk Robot <[email protected]>
> Signed-off-by: Qinglang Miao <[email protected]>
> ---
> net/qrtr/ns.c | 7 ++++---
> net/qrtr/qrtr.c | 14 +++++++++++---
> net/qrtr/qrtr.h | 2 +-
> 3 files changed, 16 insertions(+), 7 deletions(-)
>
> diff --git a/net/qrtr/ns.c b/net/qrtr/ns.c
> index 56aaf8cb6..8d00dfe81 100644
> --- a/net/qrtr/ns.c
> +++ b/net/qrtr/ns.c
> @@ -755,7 +755,7 @@ static void qrtr_ns_data_ready(struct sock *sk)
> queue_work(qrtr_ns.workqueue, &qrtr_ns.work);
> }
>
> -void qrtr_ns_init(void)
> +int qrtr_ns_init(void)
> {
> struct sockaddr_qrtr sq;
> int ret;
> @@ -766,7 +766,7 @@ void qrtr_ns_init(void)
> ret = sock_create_kern(&init_net, AF_QIPCRTR, SOCK_DGRAM,
> PF_QIPCRTR, &qrtr_ns.sock);
> if (ret < 0)
> - return;
> + return ret;
>
> ret = kernel_getsockname(qrtr_ns.sock, (struct sockaddr *)&sq);
> if (ret < 0) {
> @@ -797,12 +797,13 @@ void qrtr_ns_init(void)
> if (ret < 0)
> goto err_wq;
>
> - return;
> + return 0;
>
> err_wq:
> destroy_workqueue(qrtr_ns.workqueue);
> err_sock:
> sock_release(qrtr_ns.sock);
> + return ret;
> }
> EXPORT_SYMBOL_GPL(qrtr_ns_init);
>
> diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c
> index f4ab3ca6d..95533e451 100644
> --- a/net/qrtr/qrtr.c
> +++ b/net/qrtr/qrtr.c
> @@ -1288,12 +1288,20 @@ static int __init qrtr_proto_init(void)
>
> rc = sock_register(&qrtr_family);
> if (rc) {
> - proto_unregister(&qrtr_proto);
> - return rc;
> + goto err_proto;
> }
>
> - qrtr_ns_init();
> + rc = qrtr_ns_init();
> + if (rc) {
> + goto err_sock;
> + } >
> + return 0;
> +
> +err_sock:
> + sock_unregister(qrtr_family.family);
> +err_proto:
> + proto_unregister(&qrtr_proto);
> return rc;
> }
> postcore_initcall(qrtr_proto_init);
> diff --git a/net/qrtr/qrtr.h b/net/qrtr/qrtr.h
> index dc2b67f17..3f2d28696 100644
> --- a/net/qrtr/qrtr.h
> +++ b/net/qrtr/qrtr.h
> @@ -29,7 +29,7 @@ void qrtr_endpoint_unregister(struct qrtr_endpoint *ep);
>
> int qrtr_endpoint_post(struct qrtr_endpoint *ep, const void *data, size_t len);
>
> -void qrtr_ns_init(void);
> +int qrtr_ns_init(void);
>
> void qrtr_ns_remove(void);
>
>