{"id":2231999,"url":"http://patchwork.ozlabs.org/api/1.1/patches/2231999/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-cifs-client/patch/20260501225152.90136-3-kai.aizen.dev@gmail.com/","project":{"id":12,"url":"http://patchwork.ozlabs.org/api/1.1/projects/12/?format=json","name":"Linux CIFS Client","link_name":"linux-cifs-client","list_id":"linux-cifs.vger.kernel.org","list_email":"linux-cifs@vger.kernel.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20260501225152.90136-3-kai.aizen.dev@gmail.com>","date":"2026-05-01T22:51:52","name":"[5.15.y] ksmbd: add chann_lock to protect ksmbd_chann_list xarray","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"4fc41ac8f3ca798ee4e1b43e8adac63228b83371","submitter":{"id":93301,"url":"http://patchwork.ozlabs.org/api/1.1/people/93301/?format=json","name":"Kai Aizen","email":"kai.aizen.dev@gmail.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linux-cifs-client/patch/20260501225152.90136-3-kai.aizen.dev@gmail.com/mbox/","series":[{"id":502504,"url":"http://patchwork.ozlabs.org/api/1.1/series/502504/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-cifs-client/list/?series=502504","date":"2026-05-01T22:51:52","name":"[5.15.y] ksmbd: add chann_lock to protect ksmbd_chann_list xarray","version":1,"mbox":"http://patchwork.ozlabs.org/series/502504/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2231999/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2231999/checks/","tags":{},"headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-cifs@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256\n header.s=20251104 header.b=VEKCZymA;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c04:e001:36c::12fc:5321; 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init_rwsem for\n chann_lock is added directly after the refcnt initialisation.\n - Function bodies for free_channel_list, ksmbd_chann_del,\n lookup_chann_list, and the two xa_store sites in\n ntlm_authenticate / krb5_authenticate are byte-identical to\n mainline at the time of the fix.\n\nCVE: CVE-2026-23226\nCc: stable@vger.kernel.org # 5.15.y\nReported-by: Igor Stepansky \nSigned-off-by: Namjae Jeon \nSigned-off-by: Steve French \n[backport for linux-5.15.y, verified 2026-05-01]\n---\n fs/ksmbd/mgmt/user_session.c | 5 +++++\n fs/ksmbd/mgmt/user_session.h | 1 +\n fs/ksmbd/smb2pdu.c | 12 +++++++++++-\n 3 files changed, 17 insertions(+), 1 deletion(-)\n\n--\n2.43.0","diff":"diff --git a/fs/ksmbd/mgmt/user_session.c b/fs/ksmbd/mgmt/user_session.c\n--- a/fs/ksmbd/mgmt/user_session.c\n+++ b/fs/ksmbd/mgmt/user_session.c\n@@ -30,12 +30,14 @@ static void free_channel_list(struct ksmbd_session *sess)\n \tstruct channel *chann;\n \tunsigned long index;\n\n+\tdown_write(&sess->chann_lock);\n \txa_for_each(&sess->ksmbd_chann_list, index, chann) {\n \t\txa_erase(&sess->ksmbd_chann_list, index);\n \t\tkfree(chann);\n \t}\n\n \txa_destroy(&sess->ksmbd_chann_list);\n+\tup_write(&sess->chann_lock);\n }\n\n static void __session_rpc_close(struct ksmbd_session *sess,\n@@ -201,7 +203,9 @@ static int ksmbd_chann_del(struct ksmbd_conn *conn, struct ksmbd_session *sess)\n {\n \tstruct channel *chann;\n\n+\tdown_write(&sess->chann_lock);\n \tchann = xa_erase(&sess->ksmbd_chann_list, (long)conn);\n+\tup_write(&sess->chann_lock);\n \tif (!chann)\n \t\treturn -ENOENT;\n\n@@ -395,6 +399,7 @@ static struct ksmbd_session *__session_create(int protocol)\n \tsess->sequence_number = 1;\n \trwlock_init(&sess->tree_conns_lock);\n \tatomic_set(&sess->refcnt, 1);\n+\tinit_rwsem(&sess->chann_lock);\n\n \tret = __init_smb2_session(sess);\n \tif (ret)\ndiff --git a/fs/ksmbd/mgmt/user_session.h b/fs/ksmbd/mgmt/user_session.h\n--- a/fs/ksmbd/mgmt/user_session.h\n+++ b/fs/ksmbd/mgmt/user_session.h\n@@ -48,6 +48,7 @@ struct ksmbd_session {\n \tchar\t\t\t\tsess_key[CIFS_KEY_SIZE];\n\n \tstruct hlist_node\t\thlist;\n+\tstruct rw_semaphore\t\tchann_lock;\n \tstruct xarray\t\t\tksmbd_chann_list;\n \tstruct xarray\t\t\ttree_conns;\n \tstruct ida\t\t\ttree_conn_ida;\ndiff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c\n--- a/fs/ksmbd/smb2pdu.c\n+++ b/fs/ksmbd/smb2pdu.c\n@@ -78,7 +78,13 @@ static inline bool check_session_id(struct ksmbd_conn *conn, u64 id)\n\n struct channel *lookup_chann_list(struct ksmbd_session *sess, struct ksmbd_conn *conn)\n {\n-\treturn xa_load(&sess->ksmbd_chann_list, (long)conn);\n+\tstruct channel *chann;\n+\n+\tdown_read(&sess->chann_lock);\n+\tchann = xa_load(&sess->ksmbd_chann_list, (long)conn);\n+\tup_read(&sess->chann_lock);\n+\n+\treturn chann;\n }\n\n /**\n@@ -1570,7 +1576,9 @@ static int ntlm_authenticate(struct ksmbd_work *work,\n \t\t\t\treturn -ENOMEM;\n\n \t\t\tchann->conn = conn;\n+\t\t\tdown_write(&sess->chann_lock);\n \t\t\txa_store(&sess->ksmbd_chann_list, (long)conn, chann, GFP_KERNEL);\n+\t\t\tup_write(&sess->chann_lock);\n \t\t}\n \t}\n\n@@ -1667,7 +1675,9 @@ static int krb5_authenticate(struct ksmbd_work *work,\n \t\t\t\treturn -ENOMEM;\n\n \t\t\tchann->conn = conn;\n+\t\t\tdown_write(&sess->chann_lock);\n \t\t\txa_store(&sess->ksmbd_chann_list, (long)conn, chann, GFP_KERNEL);\n+\t\t\tup_write(&sess->chann_lock);\n \t\t}\n \t}\n\n","prefixes":["5.15.y"]}