From: Namjae Jeon <linkinjeon@kernel.org> stable inclusion from stable-v6.12.28 commit 8fb3b6c85b7e3127161623586b62abcc366caa20 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IC991R CVE: CVE-2025-37926 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit a1f46c99d9ea411f9bf30025b912d881d36fc709 upstream. A UAF issue can occur due to a race condition between ksmbd_session_rpc_open() and __session_rpc_close(). Add rpc_lock to the session to protect it. Cc: stable@vger.kernel.org Reported-by: Norbert Szetei <norbert@doyensec.com> Tested-by: Norbert Szetei <norbert@doyensec.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Conflicts: fs/smb/server/mgmt/user_session.c [0066f623bce8 ("ksmbd: use __GFP_RETRY_MAYFAIL"): flag conflicts, which does not affecting this patch.] Signed-off-by: Zizhi Wo <wozizhi@huawei.com> --- fs/smb/server/mgmt/user_session.c | 20 ++++++++++++++------ fs/smb/server/mgmt/user_session.h | 1 + 2 files changed, 15 insertions(+), 6 deletions(-) diff --git a/fs/smb/server/mgmt/user_session.c b/fs/smb/server/mgmt/user_session.c index 50239175e7b4..52cfdd8d9b70 100644 --- a/fs/smb/server/mgmt/user_session.c +++ b/fs/smb/server/mgmt/user_session.c @@ -59,10 +59,12 @@ static void ksmbd_session_rpc_clear_list(struct ksmbd_session *sess) struct ksmbd_session_rpc *entry; long index; + down_write(&sess->rpc_lock); xa_for_each(&sess->rpc_handle_list, index, entry) { xa_erase(&sess->rpc_handle_list, index); __session_rpc_close(sess, entry); } + up_write(&sess->rpc_lock); xa_destroy(&sess->rpc_handle_list); } @@ -92,7 +94,7 @@ int ksmbd_session_rpc_open(struct ksmbd_session *sess, char *rpc_name) { struct ksmbd_session_rpc *entry, *old; struct ksmbd_rpc_command *resp; - int method; + int method, id; method = __rpc_method(rpc_name); if (!method) @@ -102,26 +104,29 @@ int ksmbd_session_rpc_open(struct ksmbd_session *sess, char *rpc_name) if (!entry) return -ENOMEM; + down_read(&sess->rpc_lock); entry->method = method; - entry->id = ksmbd_ipc_id_alloc(); - if (entry->id < 0) + entry->id = id = ksmbd_ipc_id_alloc(); + if (id < 0) goto free_entry; - old = xa_store(&sess->rpc_handle_list, entry->id, entry, GFP_KERNEL); + old = xa_store(&sess->rpc_handle_list, id, entry, GFP_KERNEL); if (xa_is_err(old)) goto free_id; - resp = ksmbd_rpc_open(sess, entry->id); + resp = ksmbd_rpc_open(sess, id); if (!resp) goto erase_xa; + up_read(&sess->rpc_lock); kvfree(resp); - return entry->id; + return id; erase_xa: xa_erase(&sess->rpc_handle_list, entry->id); free_id: ksmbd_rpc_id_free(entry->id); free_entry: kfree(entry); + up_read(&sess->rpc_lock); return -EINVAL; } @@ -129,9 +134,11 @@ void ksmbd_session_rpc_close(struct ksmbd_session *sess, int id) { struct ksmbd_session_rpc *entry; + down_write(&sess->rpc_lock); entry = xa_erase(&sess->rpc_handle_list, id); if (entry) __session_rpc_close(sess, entry); + up_write(&sess->rpc_lock); } int ksmbd_session_rpc_method(struct ksmbd_session *sess, int id) @@ -420,6 +427,7 @@ static struct ksmbd_session *__session_create(int protocol) sess->sequence_number = 1; rwlock_init(&sess->tree_conns_lock); atomic_set(&sess->refcnt, 2); + init_rwsem(&sess->rpc_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 c1c4b20bd5c6..945e1397fe11 100644 --- a/fs/smb/server/mgmt/user_session.h +++ b/fs/smb/server/mgmt/user_session.h @@ -63,6 +63,7 @@ struct ksmbd_session { rwlock_t tree_conns_lock; atomic_t refcnt; + struct rw_semaphore rpc_lock; }; static inline int test_session_flag(struct ksmbd_session *sess, int bit) -- 2.39.2