diff options
| author | Namjae Jeon <linkinjeon@kernel.org> | 2026-02-09 10:43:19 +0900 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2026-02-09 09:03:04 -0600 |
| commit | 4f3a06cc57976cafa8c6f716646be6c79a99e485 (patch) | |
| tree | 90d86d012d3051905937f2eff7605c2b04ffaf2a /fs/smb/server/mgmt | |
| parent | 164cacd0ba380604253b96dc312c85366147e3f7 (diff) | |
ksmbd: add chann_lock to protect ksmbd_chann_list xarray
ksmbd_chann_list xarray lacks synchronization, allowing use-after-free in
multi-channel sessions (between lookup_chann_list() and ksmbd_chann_del).
Adds rw_semaphore chann_lock to struct ksmbd_session and protects
all xa_load/xa_store/xa_erase accesses.
Cc: stable@vger.kernel.org
Reported-by: Igor Stepansky <igor.stepansky@orca.security>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/smb/server/mgmt')
| -rw-r--r-- | fs/smb/server/mgmt/user_session.c | 5 | ||||
| -rw-r--r-- | fs/smb/server/mgmt/user_session.h | 1 |
2 files changed, 6 insertions, 0 deletions
diff --git a/fs/smb/server/mgmt/user_session.c b/fs/smb/server/mgmt/user_session.c index 68b3e0cb54d3..8c2b14ea7b0e 100644 --- a/fs/smb/server/mgmt/user_session.c +++ b/fs/smb/server/mgmt/user_session.c @@ -244,12 +244,14 @@ static void free_channel_list(struct ksmbd_session *sess) struct channel *chann; unsigned long index; + down_write(&sess->chann_lock); xa_for_each(&sess->ksmbd_chann_list, index, chann) { xa_erase(&sess->ksmbd_chann_list, index); kfree(chann); } xa_destroy(&sess->ksmbd_chann_list); + up_write(&sess->chann_lock); } static void __session_rpc_close(struct ksmbd_session *sess, @@ -434,7 +436,9 @@ static int ksmbd_chann_del(struct ksmbd_conn *conn, struct ksmbd_session *sess) { struct channel *chann; + down_write(&sess->chann_lock); chann = xa_erase(&sess->ksmbd_chann_list, (long)conn); + up_write(&sess->chann_lock); if (!chann) return -ENOENT; @@ -668,6 +672,7 @@ static struct ksmbd_session *__session_create(int protocol) rwlock_init(&sess->tree_conns_lock); atomic_set(&sess->refcnt, 2); init_rwsem(&sess->rpc_lock); + init_rwsem(&sess->chann_lock); ret = __init_smb2_session(sess); if (ret) diff --git a/fs/smb/server/mgmt/user_session.h b/fs/smb/server/mgmt/user_session.h index 176d800c2490..d94f5e128a9b 100644 --- a/fs/smb/server/mgmt/user_session.h +++ b/fs/smb/server/mgmt/user_session.h @@ -48,6 +48,7 @@ struct ksmbd_session { char sess_key[CIFS_KEY_SIZE]; struct hlist_node hlist; + struct rw_semaphore chann_lock; struct xarray ksmbd_chann_list; struct xarray tree_conns; struct ida tree_conn_ida; |