diff options
| author | Paulo Alcantara <pc@manguebit.com> | 2023-04-21 21:52:32 +0300 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2023-05-02 17:41:09 +0300 |
| commit | 90c49fce1c43e1cc152695e20363ff5087897c09 (patch) | |
| tree | cdb9f89842318870f9bbe9fed18bdb02d6af5489 /fs/cifs/connect.c | |
| parent | 1810769e3a51375ca35d7a5e5f79542858ca495a (diff) | |
| download | linux-90c49fce1c43e1cc152695e20363ff5087897c09.tar.xz | |
cifs: fix potential use-after-free bugs in TCP_Server_Info::hostname
TCP_Server_Info::hostname may be updated once or many times during
reconnect, so protect its access outside reconnect path as well and
then prevent any potential use-after-free bugs.
Cc: stable@vger.kernel.org
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/cifs/connect.c')
| -rw-r--r-- | fs/cifs/connect.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 7bfef741f758..c71505a29482 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -403,8 +403,10 @@ static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const cha if (server->hostname != target) { hostname = extract_hostname(target); if (!IS_ERR(hostname)) { + spin_lock(&server->srv_lock); kfree(server->hostname); server->hostname = hostname; + spin_unlock(&server->srv_lock); } else { cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n", __func__, PTR_ERR(hostname)); @@ -561,9 +563,7 @@ cifs_echo_request(struct work_struct *work) goto requeue_echo; rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS; - if (rc) - cifs_dbg(FYI, "Unable to send echo request to server: %s\n", - server->hostname); + cifs_server_dbg(FYI, "send echo request: rc = %d\n", rc); /* Check witness registrations */ cifs_swn_check(); @@ -1404,6 +1404,8 @@ static int match_server(struct TCP_Server_Info *server, struct smb3_fs_context * { struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr; + lockdep_assert_held(&server->srv_lock); + if (ctx->nosharesock) return 0; @@ -1810,7 +1812,9 @@ cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx) if (tcon == NULL) return -ENOMEM; + spin_lock(&server->srv_lock); scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname); + spin_unlock(&server->srv_lock); xid = get_xid(); tcon->ses = ses; |