From: Paulo Alcantara <[email protected]>
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) <[email protected]>
CC: Stable <[email protected]>
Reviewed-by: Ronnie Sahlberg <[email protected]>
Signed-off-by: Steve French <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
fs/cifs/connect.c | 2 ++
1 file changed, 2 insertions(+)
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -975,6 +975,8 @@ static void clean_demultiplex_info(struc
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);
