From 103921f069ae9189806fe5913beb40c1def7ae56 Mon Sep 17 00:00:00 2001 From: Jouni Hogander Date: Wed, 13 Nov 2019 13:45:02 +0200 Subject: [PATCH] slip: Fix memory leak in slip_open error path commit 3b5a39979dafea9d0cd69c7ae06088f7a84cdafa upstream. Driver/net/can/slcan.c is derived from slip.c. Memory leak was detected by Syzkaller in slcan. Same issue exists in slip.c and this patch is addressing the leak in slip.c. Here is the slcan memory leak trace 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>] 0xfffffffffffffff Cc: "David S. Miller" Cc: Oliver Hartkopp Cc: Lukas Bulwahn Signed-off-by: Jouni Hogander Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- drivers/net/slip/slip.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/slip/slip.c b/drivers/net/slip/slip.c index 65df455c056e1..7bf5f7f48dd02 100644 --- a/drivers/net/slip/slip.c +++ b/drivers/net/slip/slip.c @@ -867,6 +867,7 @@ err_free_chan: sl->tty = NULL; tty->disc_data = NULL; clear_bit(SLF_INUSE, &sl->flags); + free_netdev(sl->dev); err_exit: rtnl_unlock(); -- 2.47.2