6.1-stable review patch. If anyone has any objections, please let me know.
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From: Paulo Alcantara pc@manguebit.com
commit 58acd1f497162e7d282077f816faa519487be045 upstream.
Skip sessions that are being teared down (status == SES_EXITING) to avoid UAF.
Cc: stable@vger.kernel.org Signed-off-by: Paulo Alcantara (Red Hat) pc@manguebit.com Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Jianqi Ren jianqi.ren.cn@windriver.com Signed-off-by: He Zhe zhe.he@windriver.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/smb/client/ioctl.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
--- a/fs/smb/client/ioctl.c +++ b/fs/smb/client/ioctl.c @@ -246,7 +246,9 @@ static int cifs_dump_full_key(struct cif 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 @@ -254,9 +256,11 @@ static int cifs_dump_full_key(struct cif * so increment its refcount */ ses->ses_count++; + spin_unlock(&ses_it->ses_lock); found = true; goto search_end; } + spin_unlock(&ses_it->ses_lock); } } search_end: