YueHaibing 9a5e3aba2c net/x25: Fix null-ptr-deref in x25_disconnect ... commit 8999dc89497ab1c80d0718828e838c7cd5f6bffe upstream. We should check null before do x25_neigh_put in x25_disconnect, otherwise may cause null-ptr-deref like this: #include <sys/socket.h> #include <linux/x25.h> int main() { int sck_x25; sck_x25 = socket(AF_X25, SOCK_SEQPACKET, 0); close(sck_x25); return 0; } BUG: kernel NULL pointer dereference, address: 00000000000000d8 CPU: 0 PID: 4817 Comm: t2 Not tainted 5.7.0-rc3+ #159 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3- RIP: 0010:x25_disconnect+0x91/0xe0 Call Trace: x25_release+0x18a/0x1b0 __sock_release+0x3d/0xc0 sock_close+0x13/0x20 __fput+0x107/0x270 ____fput+0x9/0x10 task_work_run+0x6d/0xb0 exit_to_usermode_loop+0x102/0x110 do_syscall_64+0x23c/0x260 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Reported-by: syzbot+6db548b615e5aeefdce2@syzkaller.appspotmail.com Fixes: 4becb7ee5b3d ("net/x25: Fix x25_neigh refcnt leak when x25 disconnect") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2020-08-05 10:06:02 +02:00
..
af_x25.c	net/x25: fix nonblocking connect	2020-01-29 16:43:24 +01:00
Kconfig	x25: remove blank lines at EOF	2018-07-24 14:10:42 -07:00
Makefile
sysctl_net_x25.c
x25_dev.c	net/x25: Fix x25_neigh refcnt leak when receiving frame	2020-04-29 16:31:21 +02:00
x25_facilities.c
x25_forward.c
x25_in.c
x25_link.c
x25_out.c
x25_proc.c	proc: introduce proc_create_seq{,_data}	2018-05-16 07:23:35 +02:00
x25_route.c
x25_subr.c	net/x25: Fix null-ptr-deref in x25_disconnect	2020-08-05 10:06:02 +02:00
x25_timer.c