Hi Jianqi, On 09/12/24 09:52, jianqi.ren.cn@xxxxxxxxxxxxx wrote:
From: Paulo Alcantara <pc@xxxxxxxxxxxxx> [ Upstream commit 58acd1f497162e7d282077f816faa519487be045 ] Skip sessions that are being teared down (status == SES_EXITING) to avoid UAF. Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Paulo Alcantara (Red Hat) <pc@xxxxxxxxxxxxx> Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx> Signed-off-by: Jianqi Ren <jianqi.ren.cn@xxxxxxxxxxxxx> --- fs/smb/client/ioctl.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/fs/smb/client/ioctl.c b/fs/smb/client/ioctl.c index ae9905e2b9d4..173c8c76d31f 100644 --- a/fs/smb/client/ioctl.c +++ b/fs/smb/client/ioctl.c @@ -246,17 +246,23 @@ static int cifs_dump_full_key(struct cifs_tcon *tcon, struct smb3_full_key_debug spin_lock(&cifs_tcp_ses_lock); list_for_each_entry(server_it, &cifs_tcp_ses_list, tcp_ses_list) { list_for_each_entry(ses_it, &server_it->smb_ses_list, smb_ses_list) { - if (ses_it->Suid == out.session_id) { + spin_lock(&ses_it->ses_lock); + if (ses_it->ses_status != SES_EXITING && + ses_it->Suid == out.session_id) { ses = ses_it; /* * since we are using the session outside the crit * section, we need to make sure it won't be released * so increment its refcount */ + + lockdep_assert_held(&cifs_tcp_ses_lock);
^^ This doesn't exist in upstream commit, why is this needed ? Thanks, Harshit
ses->ses_count++; + spin_unlock(&ses_it->ses_lock); found = true; goto search_end; } + spin_unlock(&ses_it->ses_lock); } } search_end: