From: Namjae Jeon linkinjeon@kernel.org

mainline inclusion from mainline-v6.10-rc2 commit ee426bfb9d09b29987369b897fe9b6485ac2be27 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYRCR CVE: CVE-2024-49988

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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When sending an oplock break request, opinfo->conn is used, But freed ->conn can be used on multichannel. This patch add a reference count to the ksmbd_conn struct so that it can be freed when it is no longer used.

Signed-off-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Long Li leo.lilong@huawei.com --- fs/smb/server/connection.c | 4 ++- fs/smb/server/connection.h | 1 + fs/smb/server/oplock.c | 55 +++++++++++--------------------------- fs/smb/server/vfs_cache.c | 3 +++ 4 files changed, 23 insertions(+), 40 deletions(-)

diff --git a/fs/smb/server/connection.c b/fs/smb/server/connection.c index 7889df8112b4..cac80e7bfefc 100644 --- a/fs/smb/server/connection.c +++ b/fs/smb/server/connection.c @@ -39,7 +39,8 @@ void ksmbd_conn_free(struct ksmbd_conn *conn) xa_destroy(&conn->sessions); kvfree(conn->request_buf); kfree(conn->preauth_info); - kfree(conn); + if (atomic_dec_and_test(&conn->refcnt)) + kfree(conn); }

/** @@ -68,6 +69,7 @@ struct ksmbd_conn *ksmbd_conn_alloc(void) conn->um = NULL; atomic_set(&conn->req_running, 0); atomic_set(&conn->r_count, 0); + atomic_set(&conn->refcnt, 1); conn->total_credits = 1; conn->outstanding_credits = 0;

diff --git a/fs/smb/server/connection.h b/fs/smb/server/connection.h index b93e5437793e..82343afc8d04 100644 --- a/fs/smb/server/connection.h +++ b/fs/smb/server/connection.h @@ -106,6 +106,7 @@ struct ksmbd_conn { bool signing_negotiated; __le16 signing_algorithm; bool binding; + atomic_t refcnt; };

struct ksmbd_conn_ops { diff --git a/fs/smb/server/oplock.c b/fs/smb/server/oplock.c index e546ffa57b55..8ee86478287f 100644 --- a/fs/smb/server/oplock.c +++ b/fs/smb/server/oplock.c @@ -51,6 +51,7 @@ static struct oplock_info *alloc_opinfo(struct ksmbd_work *work, init_waitqueue_head(&opinfo->oplock_brk); atomic_set(&opinfo->refcount, 1); atomic_set(&opinfo->breaking_cnt, 0); + atomic_inc(&opinfo->conn->refcnt);

return opinfo; } @@ -124,6 +125,8 @@ static void free_opinfo(struct oplock_info *opinfo) { if (opinfo->is_lease) free_lease(opinfo); + if (opinfo->conn && atomic_dec_and_test(&opinfo->conn->refcnt)) + kfree(opinfo->conn); kfree(opinfo); }

@@ -163,9 +166,7 @@ static struct oplock_info *opinfo_get_list(struct ksmbd_inode *ci) !atomic_inc_not_zero(&opinfo->refcount)) opinfo = NULL; else { - atomic_inc(&opinfo->conn->r_count); if (ksmbd_conn_releasing(opinfo->conn)) { - atomic_dec(&opinfo->conn->r_count); atomic_dec(&opinfo->refcount); opinfo = NULL; } @@ -177,26 +178,11 @@ static struct oplock_info *opinfo_get_list(struct ksmbd_inode *ci) return opinfo; }

-static void opinfo_conn_put(struct oplock_info *opinfo) +void opinfo_put(struct oplock_info *opinfo) { - struct ksmbd_conn *conn; - if (!opinfo) return;

- conn = opinfo->conn; - /* - * Checking waitqueue to dropping pending requests on - * disconnection. waitqueue_active is safe because it - * uses atomic operation for condition. - */ - if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q)) - wake_up(&conn->r_count_q); - opinfo_put(opinfo); -} - -void opinfo_put(struct oplock_info *opinfo) -{ if (!atomic_dec_and_test(&opinfo->refcount)) return;

@@ -1127,14 +1113,11 @@ void smb_send_parent_lease_break_noti(struct ksmbd_file *fp, if (!atomic_inc_not_zero(&opinfo->refcount)) continue;

- atomic_inc(&opinfo->conn->r_count); - if (ksmbd_conn_releasing(opinfo->conn)) { - atomic_dec(&opinfo->conn->r_count); + if (ksmbd_conn_releasing(opinfo->conn)) continue; - }

oplock_break(opinfo, SMB2_OPLOCK_LEVEL_NONE); - opinfo_conn_put(opinfo); + opinfo_put(opinfo); } } up_read(&p_ci->m_lock); @@ -1167,13 +1150,10 @@ void smb_lazy_parent_lease_break_close(struct ksmbd_file *fp) if (!atomic_inc_not_zero(&opinfo->refcount)) continue;

- atomic_inc(&opinfo->conn->r_count); - if (ksmbd_conn_releasing(opinfo->conn)) { - atomic_dec(&opinfo->conn->r_count); + if (ksmbd_conn_releasing(opinfo->conn)) continue; - } oplock_break(opinfo, SMB2_OPLOCK_LEVEL_NONE); - opinfo_conn_put(opinfo); + opinfo_put(opinfo); } } up_read(&p_ci->m_lock); @@ -1252,7 +1232,7 @@ int smb_grant_oplock(struct ksmbd_work *work, int req_op_level, u64 pid, prev_opinfo = opinfo_get_list(ci); if (!prev_opinfo || (prev_opinfo->level == SMB2_OPLOCK_LEVEL_NONE && lctx)) { - opinfo_conn_put(prev_opinfo); + opinfo_put(prev_opinfo); goto set_lev; } prev_op_has_lease = prev_opinfo->is_lease; @@ -1262,19 +1242,19 @@ int smb_grant_oplock(struct ksmbd_work *work, int req_op_level, u64 pid, if (share_ret < 0 && prev_opinfo->level == SMB2_OPLOCK_LEVEL_EXCLUSIVE) { err = share_ret; - opinfo_conn_put(prev_opinfo); + opinfo_put(prev_opinfo); goto err_out; }

if (prev_opinfo->level != SMB2_OPLOCK_LEVEL_BATCH && prev_opinfo->level != SMB2_OPLOCK_LEVEL_EXCLUSIVE) { - opinfo_conn_put(prev_opinfo); + opinfo_put(prev_opinfo); goto op_break_not_needed; }

list_add(&work->interim_entry, &prev_opinfo->interim_list); err = oplock_break(prev_opinfo, SMB2_OPLOCK_LEVEL_II); - opinfo_conn_put(prev_opinfo); + opinfo_put(prev_opinfo); if (err == -ENOENT) goto set_lev; /* Check all oplock was freed by close */ @@ -1337,14 +1317,14 @@ static void smb_break_all_write_oplock(struct ksmbd_work *work, return; if (brk_opinfo->level != SMB2_OPLOCK_LEVEL_BATCH && brk_opinfo->level != SMB2_OPLOCK_LEVEL_EXCLUSIVE) { - opinfo_conn_put(brk_opinfo); + opinfo_put(brk_opinfo); return; }

brk_opinfo->open_trunc = is_trunc; list_add(&work->interim_entry, &brk_opinfo->interim_list); oplock_break(brk_opinfo, SMB2_OPLOCK_LEVEL_II); - opinfo_conn_put(brk_opinfo); + opinfo_put(brk_opinfo); }

/** @@ -1376,11 +1356,8 @@ void smb_break_all_levII_oplock(struct ksmbd_work *work, struct ksmbd_file *fp, if (!atomic_inc_not_zero(&brk_op->refcount)) continue;

- atomic_inc(&brk_op->conn->r_count); - if (ksmbd_conn_releasing(brk_op->conn)) { - atomic_dec(&brk_op->conn->r_count); + if (ksmbd_conn_releasing(brk_op->conn)) continue; - }

rcu_read_unlock(); if (brk_op->is_lease && (brk_op->o_lease->state & @@ -1411,7 +1388,7 @@ void smb_break_all_levII_oplock(struct ksmbd_work *work, struct ksmbd_file *fp, brk_op->open_trunc = is_trunc; oplock_break(brk_op, SMB2_OPLOCK_LEVEL_NONE); next: - opinfo_conn_put(brk_op); + opinfo_put(brk_op); rcu_read_lock(); } rcu_read_unlock(); diff --git a/fs/smb/server/vfs_cache.c b/fs/smb/server/vfs_cache.c index 8b2e37c8716e..271a23abc82f 100644 --- a/fs/smb/server/vfs_cache.c +++ b/fs/smb/server/vfs_cache.c @@ -710,6 +710,8 @@ static bool session_fd_check(struct ksmbd_tree_connect *tcon, list_for_each_entry_rcu(op, &ci->m_op_list, op_entry) { if (op->conn != conn) continue; + if (op->conn && atomic_dec_and_test(&op->conn->refcnt)) + kfree(op->conn); op->conn = NULL; } up_write(&ci->m_lock); @@ -807,6 +809,7 @@ int ksmbd_reopen_durable_fd(struct ksmbd_work *work, struct ksmbd_file *fp) if (op->conn) continue; op->conn = fp->conn; + atomic_inc(&op->conn->refcnt); } up_write(&ci->m_lock);