From: Namjae Jeon linkinjeon@kernel.org
[ Upstream commit 17ea92a9f6d0b9a97aaec5ab748e4591d70a562c ]
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 linkinjeon@kernel.org Reviewed-by: Hyunchul Lee hyc.lee@gmail.com Signed-off-by: Steve French stfrench@microsoft.com Stable-dep-of: 7b4323373d84 ("ksmbd: fix deadlock in ksmbd_find_crypto_ctx()") Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ksmbd/mgmt/user_session.c | 2 ++ fs/ksmbd/smb2pdu.c | 8 ++++++-- 2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/fs/ksmbd/mgmt/user_session.c b/fs/ksmbd/mgmt/user_session.c index 0c7b5335c12af..9c4a9c8c02795 100644 --- a/fs/ksmbd/mgmt/user_session.c +++ b/fs/ksmbd/mgmt/user_session.c @@ -241,6 +241,8 @@ 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 e17f7a5dd9974..8bfe2a6c05f92 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -600,6 +600,7 @@ 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; @@ -615,8 +616,11 @@ 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); }
/**