| Message ID | 20230207080728.15725-1-hbh25y@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v3] ksmbd: fix possible memory leak in smb2_lock() | expand |
2023-02-07 17:07 GMT+09:00, Hangyu Hua <hbh25y@gmail.com>: > argv needs to be free when setup_async_work fails or when the current > process is woken up. > > Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") > Signed-off-by: Hangyu Hua <hbh25y@gmail.com> > --- > > v2: avoid NULL pointer dereference in set_close_state_blocked_works() > v3: avoid race condition between smb2_lock() and smb2_cancel() > > fs/ksmbd/smb2pdu.c | 23 ++++++++++++++--------- > fs/ksmbd/vfs_cache.c | 2 ++ > 2 files changed, 16 insertions(+), 9 deletions(-) > > diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c > index d681f91947d9..f4079518eaf6 100644 > --- a/fs/ksmbd/smb2pdu.c > +++ b/fs/ksmbd/smb2pdu.c > @@ -6644,7 +6644,7 @@ int smb2_cancel(struct ksmbd_work *work) > struct ksmbd_conn *conn = work->conn; > struct smb2_hdr *hdr = smb2_get_msg(work->request_buf); > struct smb2_hdr *chdr; > - struct ksmbd_work *cancel_work = NULL, *iter; > + struct ksmbd_work *iter; > struct list_head *command_list; > > ksmbd_debug(SMB, "smb2 cancel called on mid %llu, async flags 0x%x\n", > @@ -6666,7 +6666,9 @@ int smb2_cancel(struct ksmbd_work *work) > "smb2 with AsyncId %llu cancelled command = 0x%x\n", > le64_to_cpu(hdr->Id.AsyncId), > le16_to_cpu(chdr->Command)); > - cancel_work = iter; > + iter->state = KSMBD_WORK_CANCELLED; > + if (iter->cancel_fn) > + iter->cancel_fn(iter->cancel_argv); > break; > } > spin_unlock(&conn->request_lock); > @@ -6685,18 +6687,12 @@ int smb2_cancel(struct ksmbd_work *work) > "smb2 with mid %llu cancelled command = 0x%x\n", > le64_to_cpu(hdr->MessageId), > le16_to_cpu(chdr->Command)); > - cancel_work = iter; > + iter->state = KSMBD_WORK_CANCELLED; > break; > } > spin_unlock(&conn->request_lock); > } > > - if (cancel_work) { > - cancel_work->state = KSMBD_WORK_CANCELLED; > - if (cancel_work->cancel_fn) > - cancel_work->cancel_fn(cancel_work->cancel_argv); > - } > - > /* For SMB2_CANCEL command itself send no response*/ > work->send_no_response = 1; > return 0; > @@ -7050,6 +7046,7 @@ int smb2_lock(struct ksmbd_work *work) > smb2_remove_blocked_lock, > argv); > if (rc) { > + kfree(argv); > err = -ENOMEM; > goto out; > } > @@ -7061,6 +7058,10 @@ int smb2_lock(struct ksmbd_work *work) > > ksmbd_vfs_posix_lock_wait(flock); > > + spin_lock(&work->conn->request_lock); > + list_del_init(&work->async_request_entry); It is called again in ksmbd_conn_try_dequeue_request(). > + spin_unlock(&work->conn->request_lock); > +
diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index d681f91947d9..f4079518eaf6 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -6644,7 +6644,7 @@ int smb2_cancel(struct ksmbd_work *work) struct ksmbd_conn *conn = work->conn; struct smb2_hdr *hdr = smb2_get_msg(work->request_buf); struct smb2_hdr *chdr; - struct ksmbd_work *cancel_work = NULL, *iter; + struct ksmbd_work *iter; struct list_head *command_list; ksmbd_debug(SMB, "smb2 cancel called on mid %llu, async flags 0x%x\n", @@ -6666,7 +6666,9 @@ int smb2_cancel(struct ksmbd_work *work) "smb2 with AsyncId %llu cancelled command = 0x%x\n", le64_to_cpu(hdr->Id.AsyncId), le16_to_cpu(chdr->Command)); - cancel_work = iter; + iter->state = KSMBD_WORK_CANCELLED; + if (iter->cancel_fn) + iter->cancel_fn(iter->cancel_argv); break; } spin_unlock(&conn->request_lock); @@ -6685,18 +6687,12 @@ int smb2_cancel(struct ksmbd_work *work) "smb2 with mid %llu cancelled command = 0x%x\n", le64_to_cpu(hdr->MessageId), le16_to_cpu(chdr->Command)); - cancel_work = iter; + iter->state = KSMBD_WORK_CANCELLED; break; } spin_unlock(&conn->request_lock); } - if (cancel_work) { - cancel_work->state = KSMBD_WORK_CANCELLED; - if (cancel_work->cancel_fn) - cancel_work->cancel_fn(cancel_work->cancel_argv); - } - /* For SMB2_CANCEL command itself send no response*/ work->send_no_response = 1; return 0; @@ -7050,6 +7046,7 @@ int smb2_lock(struct ksmbd_work *work) smb2_remove_blocked_lock, argv); if (rc) { + kfree(argv); err = -ENOMEM; goto out; } @@ -7061,6 +7058,10 @@ int smb2_lock(struct ksmbd_work *work) ksmbd_vfs_posix_lock_wait(flock); + spin_lock(&work->conn->request_lock); + list_del_init(&work->async_request_entry); + spin_unlock(&work->conn->request_lock); + if (work->state != KSMBD_WORK_ACTIVE) { list_del(&smb_lock->llist); spin_lock(&work->conn->llist_lock); @@ -7072,6 +7073,8 @@ int smb2_lock(struct ksmbd_work *work) spin_lock(&fp->f_lock); list_del(&work->fp_entry); spin_unlock(&fp->f_lock); + work->cancel_fn = NULL; + kfree(argv); rsp->hdr.Status = STATUS_CANCELLED; kfree(smb_lock); @@ -7096,6 +7099,8 @@ int smb2_lock(struct ksmbd_work *work) spin_lock(&fp->f_lock); list_del(&work->fp_entry); spin_unlock(&fp->f_lock); + work->cancel_fn = NULL; + kfree(argv); goto retry; } else if (!rc) { spin_lock(&work->conn->llist_lock); diff --git a/fs/ksmbd/vfs_cache.c b/fs/ksmbd/vfs_cache.c index da9163b00350..761a8aa540ce 100644 --- a/fs/ksmbd/vfs_cache.c +++ b/fs/ksmbd/vfs_cache.c @@ -372,6 +372,8 @@ static void set_close_state_blocked_works(struct ksmbd_file *fp) list_del(&cancel_work->fp_entry); cancel_work->state = KSMBD_WORK_CLOSED; cancel_work->cancel_fn(cancel_work->cancel_argv); + cancel_work->cancel_fn = NULL; + kfree(cancel_work->cancel_argv); } spin_unlock(&fp->f_lock); }
argv needs to be free when setup_async_work fails or when the current process is woken up. Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Signed-off-by: Hangyu Hua <hbh25y@gmail.com> --- v2: avoid NULL pointer dereference in set_close_state_blocked_works() v3: avoid race condition between smb2_lock() and smb2_cancel() fs/ksmbd/smb2pdu.c | 23 ++++++++++++++--------- fs/ksmbd/vfs_cache.c | 2 ++ 2 files changed, 16 insertions(+), 9 deletions(-)