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From ed50e1600b4483c049ce76e6bd3b665a6a9300ed Mon Sep 17 00:00:00 2001
From: Jouni Hogander <jouni.hogander@unikie.com>
Date: Wed, 13 Nov 2019 12:08:01 +0200
Subject: [PATCH] slcan: Fix memory leak in error path
Git-commit: ed50e1600b4483c049ce76e6bd3b665a6a9300ed
Patch-mainline: v5.4-rc8
References: bsc#1051510

This patch is fixing memory leak reported by Syzkaller:

Bug: memory leak unreferenced object 0xffff888067f65500 (size 4096):  comm "syz-executor043", pid 454, jiffies 4294759719 (age 11.930s)  hex dump (first 32 bytes):    73 6c 63 61 6e 30 00 00 00 00 00 00 00 00 00 00 slcan0..........    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................  backtrace:    [<00000000a06eec0d>] __kmalloc+0x18b/0x2c0    [<0000000083306e66>] kvmalloc_node+0x3a/0xc0    [<000000006ac27f87>] alloc_netdev_mqs+0x17a/0x1080    [<0000000061a996c9>] slcan_open+0x3ae/0x9a0    [<000000001226f0f9>] tty_ldisc_open.isra.1+0x76/0xc0    [<0000000019289631>] tty_set_ldisc+0x28c/0x5f0    [<000000004de5a617>] tty_ioctl+0x48d/0x1590    [<00000000daef496f>] do_vfs_ioctl+0x1c7/0x1510    [<0000000059068dbc>] ksys_ioctl+0x99/0xb0    [<000000009a6eb334>] __x64_sys_ioctl+0x78/0xb0    [<0000000053d0332e>] do_syscall_64+0x16f/0x580    [<0000000021b83b99>] entry_SYSCALL_64_after_hwframe+0x44/0xa9    [<000000008ea75434>] 0xffffffffffffffff

Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Jouni Hogander <jouni.hogander@unikie.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/can/slcan.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c
index bb6032211043..0a9f42e5fedf 100644
--- a/drivers/net/can/slcan.c
+++ b/drivers/net/can/slcan.c
@@ -617,6 +617,7 @@ static int slcan_open(struct tty_struct *tty)
 	sl->tty = NULL;
 	tty->disc_data = NULL;
 	clear_bit(SLF_INUSE, &sl->flags);
+	free_netdev(sl->dev);
 
 err_exit:
 	rtnl_unlock();
-- 
2.16.4