Commits · 8d008e64a2ebe6567c3f5e048b05842a0297350b · nexedi / linux

12 Jan, 2019 9 commits

mISDN: hfcsusb: Use struct_size() in kzalloc() · 8d008e64

Gustavo A. R. Silva authored Jan 08, 2019

One of the more common cases of allocation size calculations is finding the
size of a structure that has a zero-sized array at the end, along with memory
for some number of elements for that array. For example:

struct foo {
    int stuff;
    void *entry[];
};

instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can now
use the new struct_size() helper:

instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);

This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

8d008e64

net: clear skb->tstamp in bridge forwarding path · 41d1c883

Paolo Abeni authored Jan 08, 2019

Matteo reported forwarding issues inside the linux bridge,
if the enslaved interfaces use the fq qdisc.

Similar to commit 8203e2d8 ("net: clear skb->tstamp in
forwarding paths"), we need to clear the tstamp field in
the bridge forwarding path.

Fixes: 80b14dee ("net: Add a new socket option for a future transmit time.")
Fixes: fb420d5d ("tcp/fq: move back to CLOCK_MONOTONIC")
Reported-and-tested-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

41d1c883

Merge branch 'bpfilter-fixes' · 3f4261d4

David S. Miller authored Jan 11, 2019

Taehee Yoo says:

====================
net: bpfilter: fix two bugs in bpfilter

This patches fix two bugs in the bpfilter_umh which are related in
iptables command.

The first patch adds an exit code for UMH process.
This provides an opportunity to cleanup members of the umh_info
to modules which use the UMH.
In order to identify UMH processes, a new flag PF_UMH is added.

The second patch makes the bpfilter_umh use UMH cleanup callback.

The third patch adds re-start routine for the bpfilter_umh.
The bpfilter_umh does not re-start after error occurred.
because there is no re-start routine in the module.

The fourth patch ensures that the bpfilter.ko module will not removed while
it's being used.
The bpfilter.ko is not protected by locks or module reference counter.
Therefore that can be removed while module is being used.
In order to protect that, mutex is used.

The first and second patch are preparation patches for the third and
fourth patch.

TEST #1
   while :
   do
	modprobe bpfilter
	kill -9 <pid of the bpfilter_umh>
	iptables -vnL
   done

TEST #2
   while :
   do
	iptables -I FORWARD -m string --string ap --algo kmp &
	iptables -F &
	modprobe -rv bpfilter &
   done

TEST #3
   while :
   do
	modprobe bpfilter &
	modprobe -rv bpfilter &
   done

The TEST1 makes a failure of iptables command.
This is fixed by the third patch.

The TEST2 makes a panic because of a race condition in the bpfilter_umh
module.
This is fixed by the fourth patch.

The TEST3 makes a double-create UMH process.
This is fixed by the third and fourth patch.

v4 :
 - declare the exit_umh() as static inline
 - check stop flag in the load_umh() to avoid a double-create UMH
v3 :
 - Avoid unnecessary list lookup for non-UMH processes
 - Add a new PF_UMH flag
v2 : add the first and second patch
v1 : Initial patch
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

3f4261d4

net: bpfilter: disallow to remove bpfilter module while being used · 71a85084

Taehee Yoo authored Jan 09, 2019

The bpfilter.ko module can be removed while functions of the bpfilter.ko
are executing. so panic can occurred. in order to protect that, locks can
be used. a bpfilter_lock protects routines in the
__bpfilter_process_sockopt() but it's not enough because __exit routine
can be executed concurrently.

Now, the bpfilter_umh can not run in parallel.
So, the module do not removed while it's being used and it do not
double-create UMH process.
The members of the umh_info and the bpfilter_umh_ops are protected by
the bpfilter_umh_ops.lock.

test commands:
   while :
   do
	iptables -I FORWARD -m string --string ap --algo kmp &
	modprobe -rv bpfilter &
   done

splat looks like:
[  298.623435] BUG: unable to handle kernel paging request at fffffbfff807440b
[  298.628512] #PF error: [normal kernel read fault]
[  298.633018] PGD 124327067 P4D 124327067 PUD 11c1a3067 PMD 119eb2067 PTE 0
[  298.638859] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[  298.638859] CPU: 0 PID: 2997 Comm: iptables Not tainted 4.20.0+ #154
[  298.638859] RIP: 0010:__mutex_lock+0x6b9/0x16a0
[  298.638859] Code: c0 00 00 e8 89 82 ff ff 80 bd 8f fc ff ff 00 0f 85 d9 05 00 00 48 8b 85 80 fc ff ff 48 bf 00 00 00 00 00 fc ff df 48 c1 e8 03 <80> 3c 38 00 0f 85 1d 0e 00 00 48 8b 85 c8 fc ff ff 49 39 47 58 c6
[  298.638859] RSP: 0018:ffff88810e7777a0 EFLAGS: 00010202
[  298.638859] RAX: 1ffffffff807440b RBX: ffff888111bd4d80 RCX: 0000000000000000
[  298.638859] RDX: 1ffff110235ff806 RSI: ffff888111bd5538 RDI: dffffc0000000000
[  298.638859] RBP: ffff88810e777b30 R08: 0000000080000002 R09: 0000000000000000
[  298.638859] R10: 0000000000000000 R11: 0000000000000000 R12: fffffbfff168a42c
[  298.638859] R13: ffff888111bd4d80 R14: ffff8881040e9a05 R15: ffffffffc03a2000
[  298.638859] FS:  00007f39e3758700(0000) GS:ffff88811ae00000(0000) knlGS:0000000000000000
[  298.638859] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  298.638859] CR2: fffffbfff807440b CR3: 000000011243e000 CR4: 00000000001006f0
[  298.638859] Call Trace:
[  298.638859]  ? mutex_lock_io_nested+0x1560/0x1560
[  298.638859]  ? kasan_kmalloc+0xa0/0xd0
[  298.638859]  ? kmem_cache_alloc+0x1c2/0x260
[  298.638859]  ? __alloc_file+0x92/0x3c0
[  298.638859]  ? alloc_empty_file+0x43/0x120
[  298.638859]  ? alloc_file_pseudo+0x220/0x330
[  298.638859]  ? sock_alloc_file+0x39/0x160
[  298.638859]  ? __sys_socket+0x113/0x1d0
[  298.638859]  ? __x64_sys_socket+0x6f/0xb0
[  298.638859]  ? do_syscall_64+0x138/0x560
[  298.638859]  ? entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  298.638859]  ? __alloc_file+0x92/0x3c0
[  298.638859]  ? init_object+0x6b/0x80
[  298.638859]  ? cyc2ns_read_end+0x10/0x10
[  298.638859]  ? cyc2ns_read_end+0x10/0x10
[  298.638859]  ? hlock_class+0x140/0x140
[  298.638859]  ? sched_clock_local+0xd4/0x140
[  298.638859]  ? sched_clock_local+0xd4/0x140
[  298.638859]  ? check_flags.part.37+0x440/0x440
[  298.638859]  ? __lock_acquire+0x4f90/0x4f90
[  298.638859]  ? set_rq_offline.part.89+0x140/0x140
[ ... ]

Fixes: d2ba09c1 ("net: add skeleton of bpfilter kernel module")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

71a85084

net: bpfilter: restart bpfilter_umh when error occurred · 61fbf593

Taehee Yoo authored Jan 09, 2019

The bpfilter_umh will be stopped via __stop_umh() when the bpfilter
error occurred.
The bpfilter_umh() couldn't start again because there is no restart
routine.

The section of the bpfilter_umh_{start/end} is no longer .init.rodata
because these area should be reused in the restart routine. hence
the section name is changed to .bpfilter_umh.

The bpfilter_ops->start() is restart callback. it will be called when
bpfilter_umh is stopped.
The stop bit means bpfilter_umh is stopped. this bit is set by both
start and stop routine.

Before this patch,
Test commands:
   $ iptables -vnL
   $ kill -9 <pid of bpfilter_umh>
   $ iptables -vnL
   [  480.045136] bpfilter: write fail -32
   $ iptables -vnL

All iptables commands will fail.

After this patch,
Test commands:
   $ iptables -vnL
   $ kill -9 <pid of bpfilter_umh>
   $ iptables -vnL
   $ iptables -vnL

Now, all iptables commands will work.

Fixes: d2ba09c1 ("net: add skeleton of bpfilter kernel module")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

61fbf593

net: bpfilter: use cleanup callback to release umh_info · 5b4cb650

Taehee Yoo authored Jan 09, 2019

Now, UMH process is killed, do_exit() calls the umh_info->cleanup callback
to release members of the umh_info.
This patch makes bpfilter_umh's cleanup routine to use the
umh_info->cleanup callback.
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5b4cb650

umh: add exit routine for UMH process · 73ab1cb2

Taehee Yoo authored Jan 09, 2019

A UMH process which is created by the fork_usermode_blob() such as
bpfilter needs to release members of the umh_info when process is
terminated.
But the do_exit() does not release members of the umh_info. hence module
which uses UMH needs own code to detect whether UMH process is
terminated or not.
But this implementation needs extra code for checking the status of
UMH process. it eventually makes the code more complex.

The new PF_UMH flag is added and it is used to identify UMH processes.
The exit_umh() does not release members of the umh_info.
Hence umh_info->cleanup callback should release both members of the
umh_info and the private data.
Suggested-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

73ab1cb2

isdn: i4l: isdn_tty: Fix some concurrency double-free bugs · 2ff33d66

Jia-Ju Bai authored Jan 08, 2019

The functions isdn_tty_tiocmset() and isdn_tty_set_termios() may be
concurrently executed.

isdn_tty_tiocmset
  isdn_tty_modem_hup
    line 719: kfree(info->dtmf_state);
    line 721: kfree(info->silence_state);
    line 723: kfree(info->adpcms);
    line 725: kfree(info->adpcmr);

isdn_tty_set_termios
  isdn_tty_modem_hup
    line 719: kfree(info->dtmf_state);
    line 721: kfree(info->silence_state);
    line 723: kfree(info->adpcms);
    line 725: kfree(info->adpcmr);

Thus, some concurrency double-free bugs may occur.

These possible bugs are found by a static tool written by myself and
my manual code review.

To fix these possible bugs, the mutex lock "modem_info_mutex" used in
isdn_tty_tiocmset() is added in isdn_tty_set_termios().
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2ff33d66

vhost/vsock: fix vhost vsock cid hashing inconsistent · 7fbe078c

Zha Bin authored Jan 08, 2019

The vsock core only supports 32bit CID, but the Virtio-vsock spec define
CID (dst_cid and src_cid) as u64 and the upper 32bits is reserved as
zero. This inconsistency causes one bug in vhost vsock driver. The
scenarios is:

  0. A hash table (vhost_vsock_hash) is used to map an CID to a vsock
  object. And hash_min() is used to compute the hash key. hash_min() is
  defined as:
  (sizeof(val) <= 4 ? hash_32(val, bits) : hash_long(val, bits)).
  That means the hash algorithm has dependency on the size of macro
  argument 'val'.
  0. In function vhost_vsock_set_cid(), a 64bit CID is passed to
  hash_min() to compute the hash key when inserting a vsock object into
  the hash table.
  0. In function vhost_vsock_get(), a 32bit CID is passed to hash_min()
  to compute the hash key when looking up a vsock for an CID.

Because the different size of the CID, hash_min() returns different hash
key, thus fails to look up the vsock object for an CID.

To fix this bug, we keep CID as u64 in the IOCTLs and virtio message
headers, but explicitly convert u64 to u32 when deal with the hash table
and vsock core.

Fixes: 834e772c ("vhost/vsock: fix use-after-free in network stack callers")
Link: https://github.com/stefanha/virtio/blob/vsock/trunk/content.texSigned-off-by: Zha Bin <zhabin@linux.alibaba.com>
Reviewed-by: Liu Jiang <gerry@linux.alibaba.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

7fbe078c

11 Jan, 2019 11 commits

Merge branch 'stmmac-fixes' · 5fea7f10

David S. Miller authored Jan 11, 2019

Jose Abreu says:

====================
net: stmmac: Misc Fixes

Some small fixes for stmmac targeting -net. Detailed info in commit log.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

5fea7f10