From: Jouni Hogander jouni.hogander@unikie.com
[ Upstream commit 3b5a39979dafea9d0cd69c7ae06088f7a84cdafa ]
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" davem@davemloft.net Cc: Oliver Hartkopp socketcan@hartkopp.net Cc: Lukas Bulwahn lukas.bulwahn@gmail.com Signed-off-by: Jouni Hogander jouni.hogander@unikie.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- 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 436dd78c396a7..2901b7db9d2e1 100644 --- a/drivers/net/slip/slip.c +++ b/drivers/net/slip/slip.c @@ -859,6 +859,7 @@ static int slip_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();