From ba54b13c835609b3976714d3dde010c57d0fe23e Mon Sep 17 00:00:00 2001 From: Paulo Alcantara Date: Sat, 28 Nov 2020 16:54:02 -0300 Subject: cifs: fix potential use-after-free in cifs_echo_request() commit 212253367dc7b49ed3fc194ce71b0992eacaecf2 upstream. This patch fixes a potential use-after-free bug in cifs_echo_request(). For instance, thread 1 -------- cifs_demultiplex_thread() clean_demultiplex_info() kfree(server) thread 2 (workqueue) -------- apic_timer_interrupt() smp_apic_timer_interrupt() irq_exit() __do_softirq() run_timer_softirq() call_timer_fn() cifs_echo_request() <- use-after-free in server ptr Signed-off-by: Paulo Alcantara (SUSE) CC: Stable Reviewed-by: Ronnie Sahlberg Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/cifs/connect.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs') diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 6335ca143292..6285085195c1 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -777,6 +777,8 @@ static void clean_demultiplex_info(struct TCP_Server_Info *server) list_del_init(&server->tcp_ses_list); spin_unlock(&cifs_tcp_ses_lock); + cancel_delayed_work_sync(&server->echo); + spin_lock(&GlobalMid_Lock); server->tcpStatus = CifsExiting; spin_unlock(&GlobalMid_Lock); -- cgit v1.2.3