From: Namjae Jeon Date: Fri, 22 Jul 2022 01:17:06 +0000 (+0900) Subject: ksmbd: fix kernel oops from idr_remove() X-Git-Tag: v6.0-rc1~54^2~7 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=17ea92a9f6d0b9a97aaec5ab748e4591d70a562c;p=thirdparty%2Fkernel%2Flinux.git ksmbd: fix kernel oops from idr_remove() There is a report that kernel oops happen from idr_remove(). kernel: BUG: kernel NULL pointer dereference, address: 0000000000000010 kernel: RIP: 0010:idr_remove+0x1/0x20 kernel: __ksmbd_close_fd+0xb2/0x2d0 [ksmbd] kernel: ksmbd_vfs_read+0x91/0x190 [ksmbd] kernel: ksmbd_fd_put+0x29/0x40 [ksmbd] kernel: smb2_read+0x210/0x390 [ksmbd] kernel: __process_request+0xa4/0x180 [ksmbd] kernel: __handle_ksmbd_work+0xf0/0x290 [ksmbd] kernel: handle_ksmbd_work+0x2d/0x50 [ksmbd] kernel: process_one_work+0x21d/0x3f0 kernel: worker_thread+0x50/0x3d0 kernel: rescuer_thread+0x390/0x390 kernel: kthread+0xee/0x120 kthread_complete_and_exit+0x20/0x20 kernel: ret_from_fork+0x22/0x30 While accessing files, If connection is disconnected, windows send session setup request included previous session destroy. But while still processing requests on previous session, this request destroy file table, which mean file table idr will be freed and set to NULL. So kernel oops happen from ft->idr in __ksmbd_close_fd(). This patch don't directly destroy session in destroy_previous_session(). It just set to KSMBD_SESS_EXITING so that connection will be terminated after finishing the rest of requests. Signed-off-by: Namjae Jeon Reviewed-by: Hyunchul Lee Signed-off-by: Steve French --- diff --git a/fs/ksmbd/mgmt/user_session.c b/fs/ksmbd/mgmt/user_session.c index 25e9ba3b75506..b9acb6770b031 100644 --- a/fs/ksmbd/mgmt/user_session.c +++ b/fs/ksmbd/mgmt/user_session.c @@ -239,6 +239,8 @@ struct ksmbd_session *ksmbd_session_lookup_all(struct ksmbd_conn *conn, sess = ksmbd_session_lookup(conn, id); if (!sess && conn->binding) sess = ksmbd_session_lookup_slowpath(id); + if (sess && sess->state != SMB2_SESSION_VALID) + sess = NULL; return sess; } diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index 02a7df0eac4ce..5d01d4077e065 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -593,6 +593,7 @@ static void destroy_previous_session(struct ksmbd_conn *conn, { struct ksmbd_session *prev_sess = ksmbd_session_lookup_slowpath(id); struct ksmbd_user *prev_user; + struct channel *chann; if (!prev_sess) return; @@ -608,8 +609,11 @@ static void destroy_previous_session(struct ksmbd_conn *conn, } put_session(prev_sess); - xa_erase(&conn->sessions, prev_sess->id); - ksmbd_session_destroy(prev_sess); + prev_sess->state = SMB2_SESSION_EXPIRED; + write_lock(&prev_sess->chann_lock); + list_for_each_entry(chann, &prev_sess->ksmbd_chann_list, chann_list) + chann->conn->status = KSMBD_SESS_EXITING; + write_unlock(&prev_sess->chann_lock); } /**