From c90c53658977e7035ad5f59719238607c1a76071 Mon Sep 17 00:00:00 2001
From: Jouni Hogander <jouni.hogander@unikie.com>
Date: Wed, 20 Nov 2019 09:08:16 +0200
Subject: [PATCH] net-sysfs: Fix reference count leak in
rx|netdev_queue_add_kobject
Git-commit: b8eb718348b8fb30b5a7d0a8fce26fb3f4ac741b
Patch-mainline: v5.4
References: git-fixes
kobject_init_and_add takes reference even when it fails. This has
to be given up by the caller in error handling. Otherwise memory
allocated by kobject_init_and_add is never freed. Originally found
by Syzkaller:
BUG: memory leak
unreferenced object 0xffff8880679f8b08 (size 8):
comm "netdev_register", pid 269, jiffies 4294693094 (age 12.132s)
hex dump (first 8 bytes):
72 78 2d 30 00 36 20 d4 rx-0.6 .
backtrace:
[<000000008c93818e>] __kmalloc_track_caller+0x16e/0x290
[<000000001f2e4e49>] kvasprintf+0xb1/0x140
[<000000007f313394>] kvasprintf_const+0x56/0x160
[<00000000aeca11c8>] kobject_set_name_vargs+0x5b/0x140
[<0000000073a0367c>] kobject_init_and_add+0xd8/0x170
[<0000000088838e4b>] net_rx_queue_update_kobjects+0x152/0x560
[<000000006be5f104>] netdev_register_kobject+0x210/0x380
[<00000000e31dab9d>] register_netdevice+0xa1b/0xf00
[<00000000f68b2465>] __tun_chr_ioctl+0x20d5/0x3dd0
[<000000004c50599f>] tun_chr_ioctl+0x2f/0x40
[<00000000bbd4c317>] do_vfs_ioctl+0x1c7/0x1510
[<00000000d4c59e8f>] ksys_ioctl+0x99/0xb0
[<00000000946aea81>] __x64_sys_ioctl+0x78/0xb0
[<0000000038d946e5>] do_syscall_64+0x16f/0x580
[<00000000e0aa5d8f>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[<00000000285b3d1a>] 0xffffffffffffffff
Cc: David Miller <davem@davemloft.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: Denis Kirjanov <denis.kirjanov@suse.com>
---
net/core/net-sysfs.c | 24 +++++++++++++-----------
1 file changed, 13 insertions(+), 11 deletions(-)
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 69ab2e80f211..5b8866bcd45b 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -890,21 +890,23 @@ static int rx_queue_add_kobject(struct net_device *dev, int index)
error = kobject_init_and_add(kobj, &rx_queue_ktype, NULL,
"rx-%u", index);
if (error)
- return error;
+ goto err;
dev_hold(queue->dev);
if (dev->sysfs_rx_queue_group) {
error = sysfs_create_group(kobj, dev->sysfs_rx_queue_group);
- if (error) {
- kobject_put(kobj);
- return error;
- }
+ if (error)
+ goto err;
}
kobject_uevent(kobj, KOBJ_ADD);
return error;
+
+err:
+ kobject_put(kobj);
+ return error;
}
#endif /* CONFIG_SYSFS */
@@ -1420,21 +1422,21 @@ static int netdev_queue_add_kobject(struct net_device *dev, int index)
error = kobject_init_and_add(kobj, &netdev_queue_ktype, NULL,
"tx-%u", index);
if (error)
- return error;
+ goto err;
dev_hold(queue->dev);
#ifdef CONFIG_BQL
error = sysfs_create_group(kobj, &dql_group);
- if (error) {
- kobject_put(kobj);
- return error;
- }
+ if (error)
+ goto err;
#endif
kobject_uevent(kobj, KOBJ_ADD);
- return 0;
+err:
+ kobject_put(kobj);
+ return error;
}
#endif /* CONFIG_SYSFS */
--
2.16.4