[PATCH] net: qrtr: fix null-ptr-deref in qrtr_ns_remove
From: Qinglang Miao <hidden>
Date: 2021-01-05 02:35:54
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 <redacted> Signed-off-by: Qinglang Miao <redacted> --- 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);
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2.23.0