From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Hulk Robot <hulkci@huawei.com>,
Jason Wang <jasowang@redhat.com>,
Yang Yingliang <yangyingliang@huawei.com>,
"David S. Miller" <davem@davemloft.net>
Subject: [PATCH 4.14 13/45] tun: fix use-after-free when register netdev failed
Date: Wed, 18 Sep 2019 08:18:51 +0200 [thread overview]
Message-ID: <20190918061224.247780405@linuxfoundation.org> (raw)
In-Reply-To: <20190918061222.854132812@linuxfoundation.org>
From: Yang Yingliang <yangyingliang@huawei.com>
[ Upstream commit 77f22f92dff8e7b45c7786a430626d38071d4670 ]
I got a UAF repport in tun driver when doing fuzzy test:
[ 466.269490] ==================================================================
[ 466.271792] BUG: KASAN: use-after-free in tun_chr_read_iter+0x2ca/0x2d0
[ 466.271806] Read of size 8 at addr ffff888372139250 by task tun-test/2699
[ 466.271810]
[ 466.271824] CPU: 1 PID: 2699 Comm: tun-test Not tainted 5.3.0-rc1-00001-g5a9433db2614-dirty #427
[ 466.271833] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
[ 466.271838] Call Trace:
[ 466.271858] dump_stack+0xca/0x13e
[ 466.271871] ? tun_chr_read_iter+0x2ca/0x2d0
[ 466.271890] print_address_description+0x79/0x440
[ 466.271906] ? vprintk_func+0x5e/0xf0
[ 466.271920] ? tun_chr_read_iter+0x2ca/0x2d0
[ 466.271935] __kasan_report+0x15c/0x1df
[ 466.271958] ? tun_chr_read_iter+0x2ca/0x2d0
[ 466.271976] kasan_report+0xe/0x20
[ 466.271987] tun_chr_read_iter+0x2ca/0x2d0
[ 466.272013] do_iter_readv_writev+0x4b7/0x740
[ 466.272032] ? default_llseek+0x2d0/0x2d0
[ 466.272072] do_iter_read+0x1c5/0x5e0
[ 466.272110] vfs_readv+0x108/0x180
[ 466.299007] ? compat_rw_copy_check_uvector+0x440/0x440
[ 466.299020] ? fsnotify+0x888/0xd50
[ 466.299040] ? __fsnotify_parent+0xd0/0x350
[ 466.299064] ? fsnotify_first_mark+0x1e0/0x1e0
[ 466.304548] ? vfs_write+0x264/0x510
[ 466.304569] ? ksys_write+0x101/0x210
[ 466.304591] ? do_preadv+0x116/0x1a0
[ 466.304609] do_preadv+0x116/0x1a0
[ 466.309829] do_syscall_64+0xc8/0x600
[ 466.309849] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 466.309861] RIP: 0033:0x4560f9
[ 466.309875] Code: 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
[ 466.309889] RSP: 002b:00007ffffa5166e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000127
[ 466.322992] RAX: ffffffffffffffda RBX: 0000000000400460 RCX: 00000000004560f9
[ 466.322999] RDX: 0000000000000003 RSI: 00000000200008c0 RDI: 0000000000000003
[ 466.323007] RBP: 00007ffffa516700 R08: 0000000000000004 R09: 0000000000000000
[ 466.323014] R10: 0000000000000000 R11: 0000000000000206 R12: 000000000040cb10
[ 466.323021] R13: 0000000000000000 R14: 00000000006d7018 R15: 0000000000000000
[ 466.323057]
[ 466.323064] Allocated by task 2605:
[ 466.335165] save_stack+0x19/0x80
[ 466.336240] __kasan_kmalloc.constprop.8+0xa0/0xd0
[ 466.337755] kmem_cache_alloc+0xe8/0x320
[ 466.339050] getname_flags+0xca/0x560
[ 466.340229] user_path_at_empty+0x2c/0x50
[ 466.341508] vfs_statx+0xe6/0x190
[ 466.342619] __do_sys_newstat+0x81/0x100
[ 466.343908] do_syscall_64+0xc8/0x600
[ 466.345303] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 466.347034]
[ 466.347517] Freed by task 2605:
[ 466.348471] save_stack+0x19/0x80
[ 466.349476] __kasan_slab_free+0x12e/0x180
[ 466.350726] kmem_cache_free+0xc8/0x430
[ 466.351874] putname+0xe2/0x120
[ 466.352921] filename_lookup+0x257/0x3e0
[ 466.354319] vfs_statx+0xe6/0x190
[ 466.355498] __do_sys_newstat+0x81/0x100
[ 466.356889] do_syscall_64+0xc8/0x600
[ 466.358037] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 466.359567]
[ 466.360050] The buggy address belongs to the object at ffff888372139100
[ 466.360050] which belongs to the cache names_cache of size 4096
[ 466.363735] The buggy address is located 336 bytes inside of
[ 466.363735] 4096-byte region [ffff888372139100, ffff88837213a100)
[ 466.367179] The buggy address belongs to the page:
[ 466.368604] page:ffffea000dc84e00 refcount:1 mapcount:0 mapping:ffff8883df1b4f00 index:0x0 compound_mapcount: 0
[ 466.371582] flags: 0x2fffff80010200(slab|head)
[ 466.372910] raw: 002fffff80010200 dead000000000100 dead000000000122 ffff8883df1b4f00
[ 466.375209] raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
[ 466.377778] page dumped because: kasan: bad access detected
[ 466.379730]
[ 466.380288] Memory state around the buggy address:
[ 466.381844] ffff888372139100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 466.384009] ffff888372139180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 466.386131] >ffff888372139200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 466.388257] ^
[ 466.390234] ffff888372139280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 466.392512] ffff888372139300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 466.394667] ==================================================================
tun_chr_read_iter() accessed the memory which freed by free_netdev()
called by tun_set_iff():
CPUA CPUB
tun_set_iff()
alloc_netdev_mqs()
tun_attach()
tun_chr_read_iter()
tun_get()
tun_do_read()
tun_ring_recv()
register_netdevice() <-- inject error
goto err_detach
tun_detach_all() <-- set RCV_SHUTDOWN
free_netdev() <-- called from
err_free_dev path
netdev_freemem() <-- free the memory
without check refcount
(In this path, the refcount cannot prevent
freeing the memory of dev, and the memory
will be used by dev_put() called by
tun_chr_read_iter() on CPUB.)
(Break from tun_ring_recv(),
because RCV_SHUTDOWN is set)
tun_put()
dev_put() <-- use the memory
freed by netdev_freemem()
Put the publishing of tfile->tun after register_netdevice(),
so tun_get() won't get the tun pointer that freed by
err_detach path if register_netdevice() failed.
Fixes: eb0fb363f920 ("tuntap: attach queue 0 before registering netdevice")
Reported-by: Hulk Robot <hulkci@huawei.com>
Suggested-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/tun.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -630,7 +630,8 @@ static void tun_detach_all(struct net_de
module_put(THIS_MODULE);
}
-static int tun_attach(struct tun_struct *tun, struct file *file, bool skip_filter)
+static int tun_attach(struct tun_struct *tun, struct file *file,
+ bool skip_filter, bool publish_tun)
{
struct tun_file *tfile = file->private_data;
struct net_device *dev = tun->dev;
@@ -672,7 +673,8 @@ static int tun_attach(struct tun_struct
tfile->queue_index = tun->numqueues;
tfile->socket.sk->sk_shutdown &= ~RCV_SHUTDOWN;
- rcu_assign_pointer(tfile->tun, tun);
+ if (publish_tun)
+ rcu_assign_pointer(tfile->tun, tun);
rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
tun->numqueues++;
@@ -2011,7 +2013,7 @@ static int tun_set_iff(struct net *net,
if (err < 0)
return err;
- err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER);
+ err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER, true);
if (err < 0)
return err;
@@ -2100,13 +2102,17 @@ static int tun_set_iff(struct net *net,
NETIF_F_HW_VLAN_STAG_TX);
INIT_LIST_HEAD(&tun->disabled);
- err = tun_attach(tun, file, false);
+ err = tun_attach(tun, file, false, false);
if (err < 0)
goto err_free_flow;
err = register_netdevice(tun->dev);
if (err < 0)
goto err_detach;
+ /* free_netdev() won't check refcnt, to aovid race
+ * with dev_put() we need publish tun after registration.
+ */
+ rcu_assign_pointer(tfile->tun, tun);
}
netif_carrier_on(tun->dev);
@@ -2252,7 +2258,7 @@ static int tun_set_queue(struct file *fi
ret = security_tun_dev_attach_queue(tun->security);
if (ret < 0)
goto unlock;
- ret = tun_attach(tun, file, false);
+ ret = tun_attach(tun, file, false, true);
} else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
tun = rtnl_dereference(tfile->tun);
if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached)
next prev parent reply other threads:[~2019-09-18 6:20 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-18 6:18 [PATCH 4.14 00/45] 4.14.145-stable review Greg Kroah-Hartman
2019-09-18 6:18 ` [PATCH 4.14 01/45] bridge/mdb: remove wrong use of NLM_F_MULTI Greg Kroah-Hartman
2019-09-18 6:18 ` [PATCH 4.14 02/45] cdc_ether: fix rndis support for Mediatek based smartphones Greg Kroah-Hartman
2019-09-18 6:18 ` [PATCH 4.14 03/45] ipv6: Fix the link time qualifier of ping_v6_proc_exit_net() Greg Kroah-Hartman
2019-09-18 6:18 ` [PATCH 4.14 04/45] isdn/capi: check message length in capi_write() Greg Kroah-Hartman
2019-09-18 6:18 ` [PATCH 4.14 05/45] net: Fix null de-reference of device refcount Greg Kroah-Hartman
2019-09-18 6:18 ` [PATCH 4.14 06/45] net: gso: Fix skb_segment splat when splitting gso_size mangled skb having linear-headed frag_list Greg Kroah-Hartman
2019-09-18 6:18 ` [PATCH 4.14 07/45] net: phylink: Fix flow control resolution Greg Kroah-Hartman
2019-09-18 6:18 ` [PATCH 4.14 08/45] sch_hhf: ensure quantum and hhf_non_hh_weight are non-zero Greg Kroah-Hartman
2019-09-18 6:18 ` [PATCH 4.14 09/45] sctp: Fix the link time qualifier of sctp_ctrlsock_exit() Greg Kroah-Hartman
2019-09-18 6:18 ` [PATCH 4.14 10/45] sctp: use transport pf_retrans in sctp_do_8_2_transport_strike Greg Kroah-Hartman
2019-09-18 6:18 ` [PATCH 4.14 11/45] tcp: fix tcp_ecn_withdraw_cwr() to clear TCP_ECN_QUEUE_CWR Greg Kroah-Hartman
2019-09-18 6:18 ` [PATCH 4.14 12/45] tipc: add NULL pointer check before calling kfree_rcu Greg Kroah-Hartman
2019-09-18 6:18 ` Greg Kroah-Hartman [this message]
2019-09-18 6:18 ` [PATCH 4.14 14/45] btrfs: compression: add helper for type to string conversion Greg Kroah-Hartman
2019-09-18 6:18 ` [PATCH 4.14 15/45] btrfs: correctly validate compression type Greg Kroah-Hartman
2019-09-18 6:18 ` [PATCH 4.14 16/45] Revert "MIPS: SiByte: Enable swiotlb for SWARM, LittleSur and BigSur" Greg Kroah-Hartman
2019-09-18 6:18 ` [PATCH 4.14 17/45] gpiolib: acpi: Add gpiolib_acpi_run_edge_events_on_boot option and blacklist Greg Kroah-Hartman
2019-09-18 6:18 ` [PATCH 4.14 18/45] gpio: fix line flag validation in linehandle_create Greg Kroah-Hartman
2019-09-18 6:18 ` [PATCH 4.14 19/45] gpio: fix line flag validation in lineevent_create Greg Kroah-Hartman
2019-09-18 6:18 ` [PATCH 4.14 20/45] Btrfs: fix assertion failure during fsync and use of stale transaction Greg Kroah-Hartman
2019-09-18 6:18 ` [PATCH 4.14 21/45] genirq: Prevent NULL pointer dereference in resend_irqs() Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 22/45] KVM: s390: Do not leak kernel stack data in the KVM_S390_INTERRUPT ioctl Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 23/45] KVM: x86: work around leak of uninitialized stack contents Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 24/45] KVM: nVMX: handle page fault in vmread Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 25/45] MIPS: VDSO: Prevent use of smp_processor_id() Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 26/45] MIPS: VDSO: Use same -m%-float cflag as the kernel proper Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 27/45] powerpc: Add barrier_nospec to raw_copy_in_user() Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 28/45] drm/meson: Add support for XBGR8888 & ABGR8888 formats Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 29/45] clk: rockchip: Dont yell about bad mmc phases when getting Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 30/45] mtd: rawnand: mtk: Fix wrongly assigned OOB buffer pointer issue Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 31/45] PCI: Always allow probing with driver_override Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 32/45] ubifs: Correctly use tnc_next() in search_dh_cookie() Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 33/45] driver core: Fix use-after-free and double free on glue directory Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 34/45] crypto: talitos - check AES key size Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 35/45] crypto: talitos - fix CTR alg blocksize Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 36/45] crypto: talitos - check data blocksize in ablkcipher Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 37/45] crypto: talitos - fix ECB algs ivsize Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 38/45] crypto: talitos - Do not modify req->cryptlen on decryption Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 39/45] crypto: talitos - HMAC SNOOP NO AFEU mode requires SW icv checking Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 40/45] firmware: ti_sci: Always request response from firmware Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 41/45] drm/mediatek: mtk_drm_drv.c: Add of_node_put() before goto Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 42/45] Revert "Bluetooth: btusb: driver to enable the usb-wakeup feature" Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 43/45] platform/x86: pmc_atom: Add CB4063 Beckhoff Automation board to critclk_systems DMI table Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 44/45] nvmem: Use the same permissions for eeprom as for nvmem Greg Kroah-Hartman
2019-09-18 6:19 ` [PATCH 4.14 45/45] x86/build: Add -Wnoaddress-of-packed-member to REALMODE_CFLAGS, to silence GCC9 build warning Greg Kroah-Hartman
2019-09-18 13:19 ` [PATCH 4.14 00/45] 4.14.145-stable review kernelci.org bot
2019-09-18 13:55 ` Naresh Kamboju
2019-09-18 16:28 ` Jon Hunter
2019-09-18 16:28 ` Jon Hunter
2019-09-18 19:37 ` Guenter Roeck
2019-09-19 1:26 ` shuah
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