<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/net/llc, branch v5.3-rc8</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 281</title>
<updated>2019-06-05T15:36:36+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2019-05-29T14:17:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0e9facca1b882b4034acc8f38a4f2ab6797f270a'/>
<id>0e9facca1b882b4034acc8f38a4f2ab6797f270a</id>
<content type='text'>
Based on 1 normalized pattern(s):

  this program can be redistributed or modified under the terms of the
  gnu general public license version 2 as published by the free
  software foundation this program is distributed without any warranty
  or implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license version 2 for more
  details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 1 file(s).

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Alexios Zavras &lt;alexios.zavras@intel.com&gt;
Reviewed-by: Allison Randal &lt;allison@lohutok.net&gt;
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.551133917@linutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Based on 1 normalized pattern(s):

  this program can be redistributed or modified under the terms of the
  gnu general public license version 2 as published by the free
  software foundation this program is distributed without any warranty
  or implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license version 2 for more
  details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 1 file(s).

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Alexios Zavras &lt;alexios.zavras@intel.com&gt;
Reviewed-by: Allison Randal &lt;allison@lohutok.net&gt;
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.551133917@linutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>llc: fix skb leak in llc_build_and_send_ui_pkt()</title>
<updated>2019-05-29T00:25:23+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2019-05-28T00:35:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8fb44d60d4142cd2a440620cd291d346e23c131e'/>
<id>8fb44d60d4142cd2a440620cd291d346e23c131e</id>
<content type='text'>
If llc_mac_hdr_init() returns an error, we must drop the skb
since no llc_build_and_send_ui_pkt() caller will take care of this.

BUG: memory leak
unreferenced object 0xffff8881202b6800 (size 2048):
  comm "syz-executor907", pid 7074, jiffies 4294943781 (age 8.590s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    1a 00 07 40 00 00 00 00 00 00 00 00 00 00 00 00  ...@............
  backtrace:
    [&lt;00000000e25b5abe&gt;] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline]
    [&lt;00000000e25b5abe&gt;] slab_post_alloc_hook mm/slab.h:439 [inline]
    [&lt;00000000e25b5abe&gt;] slab_alloc mm/slab.c:3326 [inline]
    [&lt;00000000e25b5abe&gt;] __do_kmalloc mm/slab.c:3658 [inline]
    [&lt;00000000e25b5abe&gt;] __kmalloc+0x161/0x2c0 mm/slab.c:3669
    [&lt;00000000a1ae188a&gt;] kmalloc include/linux/slab.h:552 [inline]
    [&lt;00000000a1ae188a&gt;] sk_prot_alloc+0xd6/0x170 net/core/sock.c:1608
    [&lt;00000000ded25bbe&gt;] sk_alloc+0x35/0x2f0 net/core/sock.c:1662
    [&lt;000000002ecae075&gt;] llc_sk_alloc+0x35/0x170 net/llc/llc_conn.c:950
    [&lt;00000000551f7c47&gt;] llc_ui_create+0x7b/0x140 net/llc/af_llc.c:173
    [&lt;0000000029027f0e&gt;] __sock_create+0x164/0x250 net/socket.c:1430
    [&lt;000000008bdec225&gt;] sock_create net/socket.c:1481 [inline]
    [&lt;000000008bdec225&gt;] __sys_socket+0x69/0x110 net/socket.c:1523
    [&lt;00000000b6439228&gt;] __do_sys_socket net/socket.c:1532 [inline]
    [&lt;00000000b6439228&gt;] __se_sys_socket net/socket.c:1530 [inline]
    [&lt;00000000b6439228&gt;] __x64_sys_socket+0x1e/0x30 net/socket.c:1530
    [&lt;00000000cec820c1&gt;] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301
    [&lt;000000000c32554f&gt;] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: memory leak
unreferenced object 0xffff88811d750d00 (size 224):
  comm "syz-executor907", pid 7074, jiffies 4294943781 (age 8.600s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 f0 0c 24 81 88 ff ff 00 68 2b 20 81 88 ff ff  ...$.....h+ ....
  backtrace:
    [&lt;0000000053026172&gt;] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline]
    [&lt;0000000053026172&gt;] slab_post_alloc_hook mm/slab.h:439 [inline]
    [&lt;0000000053026172&gt;] slab_alloc_node mm/slab.c:3269 [inline]
    [&lt;0000000053026172&gt;] kmem_cache_alloc_node+0x153/0x2a0 mm/slab.c:3579
    [&lt;00000000fa8f3c30&gt;] __alloc_skb+0x6e/0x210 net/core/skbuff.c:198
    [&lt;00000000d96fdafb&gt;] alloc_skb include/linux/skbuff.h:1058 [inline]
    [&lt;00000000d96fdafb&gt;] alloc_skb_with_frags+0x5f/0x250 net/core/skbuff.c:5327
    [&lt;000000000a34a2e7&gt;] sock_alloc_send_pskb+0x269/0x2a0 net/core/sock.c:2225
    [&lt;00000000ee39999b&gt;] sock_alloc_send_skb+0x32/0x40 net/core/sock.c:2242
    [&lt;00000000e034d810&gt;] llc_ui_sendmsg+0x10a/0x540 net/llc/af_llc.c:933
    [&lt;00000000c0bc8445&gt;] sock_sendmsg_nosec net/socket.c:652 [inline]
    [&lt;00000000c0bc8445&gt;] sock_sendmsg+0x54/0x70 net/socket.c:671
    [&lt;000000003b687167&gt;] __sys_sendto+0x148/0x1f0 net/socket.c:1964
    [&lt;00000000922d78d9&gt;] __do_sys_sendto net/socket.c:1976 [inline]
    [&lt;00000000922d78d9&gt;] __se_sys_sendto net/socket.c:1972 [inline]
    [&lt;00000000922d78d9&gt;] __x64_sys_sendto+0x2a/0x30 net/socket.c:1972
    [&lt;00000000cec820c1&gt;] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301
    [&lt;000000000c32554f&gt;] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If llc_mac_hdr_init() returns an error, we must drop the skb
since no llc_build_and_send_ui_pkt() caller will take care of this.

BUG: memory leak
unreferenced object 0xffff8881202b6800 (size 2048):
  comm "syz-executor907", pid 7074, jiffies 4294943781 (age 8.590s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    1a 00 07 40 00 00 00 00 00 00 00 00 00 00 00 00  ...@............
  backtrace:
    [&lt;00000000e25b5abe&gt;] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline]
    [&lt;00000000e25b5abe&gt;] slab_post_alloc_hook mm/slab.h:439 [inline]
    [&lt;00000000e25b5abe&gt;] slab_alloc mm/slab.c:3326 [inline]
    [&lt;00000000e25b5abe&gt;] __do_kmalloc mm/slab.c:3658 [inline]
    [&lt;00000000e25b5abe&gt;] __kmalloc+0x161/0x2c0 mm/slab.c:3669
    [&lt;00000000a1ae188a&gt;] kmalloc include/linux/slab.h:552 [inline]
    [&lt;00000000a1ae188a&gt;] sk_prot_alloc+0xd6/0x170 net/core/sock.c:1608
    [&lt;00000000ded25bbe&gt;] sk_alloc+0x35/0x2f0 net/core/sock.c:1662
    [&lt;000000002ecae075&gt;] llc_sk_alloc+0x35/0x170 net/llc/llc_conn.c:950
    [&lt;00000000551f7c47&gt;] llc_ui_create+0x7b/0x140 net/llc/af_llc.c:173
    [&lt;0000000029027f0e&gt;] __sock_create+0x164/0x250 net/socket.c:1430
    [&lt;000000008bdec225&gt;] sock_create net/socket.c:1481 [inline]
    [&lt;000000008bdec225&gt;] __sys_socket+0x69/0x110 net/socket.c:1523
    [&lt;00000000b6439228&gt;] __do_sys_socket net/socket.c:1532 [inline]
    [&lt;00000000b6439228&gt;] __se_sys_socket net/socket.c:1530 [inline]
    [&lt;00000000b6439228&gt;] __x64_sys_socket+0x1e/0x30 net/socket.c:1530
    [&lt;00000000cec820c1&gt;] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301
    [&lt;000000000c32554f&gt;] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: memory leak
unreferenced object 0xffff88811d750d00 (size 224):
  comm "syz-executor907", pid 7074, jiffies 4294943781 (age 8.600s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 f0 0c 24 81 88 ff ff 00 68 2b 20 81 88 ff ff  ...$.....h+ ....
  backtrace:
    [&lt;0000000053026172&gt;] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline]
    [&lt;0000000053026172&gt;] slab_post_alloc_hook mm/slab.h:439 [inline]
    [&lt;0000000053026172&gt;] slab_alloc_node mm/slab.c:3269 [inline]
    [&lt;0000000053026172&gt;] kmem_cache_alloc_node+0x153/0x2a0 mm/slab.c:3579
    [&lt;00000000fa8f3c30&gt;] __alloc_skb+0x6e/0x210 net/core/skbuff.c:198
    [&lt;00000000d96fdafb&gt;] alloc_skb include/linux/skbuff.h:1058 [inline]
    [&lt;00000000d96fdafb&gt;] alloc_skb_with_frags+0x5f/0x250 net/core/skbuff.c:5327
    [&lt;000000000a34a2e7&gt;] sock_alloc_send_pskb+0x269/0x2a0 net/core/sock.c:2225
    [&lt;00000000ee39999b&gt;] sock_alloc_send_skb+0x32/0x40 net/core/sock.c:2242
    [&lt;00000000e034d810&gt;] llc_ui_sendmsg+0x10a/0x540 net/llc/af_llc.c:933
    [&lt;00000000c0bc8445&gt;] sock_sendmsg_nosec net/socket.c:652 [inline]
    [&lt;00000000c0bc8445&gt;] sock_sendmsg+0x54/0x70 net/socket.c:671
    [&lt;000000003b687167&gt;] __sys_sendto+0x148/0x1f0 net/socket.c:1964
    [&lt;00000000922d78d9&gt;] __do_sys_sendto net/socket.c:1976 [inline]
    [&lt;00000000922d78d9&gt;] __se_sys_sendto net/socket.c:1972 [inline]
    [&lt;00000000922d78d9&gt;] __x64_sys_sendto+0x2a/0x30 net/socket.c:1972
    [&lt;00000000cec820c1&gt;] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301
    [&lt;000000000c32554f&gt;] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>treewide: Add SPDX license identifier - Makefile/Kconfig</title>
<updated>2019-05-21T08:50:46+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2019-05-19T12:07:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ec8f24b7faaf3d4799a7c3f4c1b87f6b02778ad1'/>
<id>ec8f24b7faaf3d4799a7c3f4c1b87f6b02778ad1</id>
<content type='text'>
Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>llc: Check address length before reading address field</title>
<updated>2019-04-12T17:25:03+00:00</updated>
<author>
<name>Tetsuo Handa</name>
<email>penguin-kernel@I-love.SAKURA.ne.jp</email>
</author>
<published>2019-04-12T10:55:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c68e747d0a98f44a4e49071940a692fa83630e47'/>
<id>c68e747d0a98f44a4e49071940a692fa83630e47</id>
<content type='text'>
KMSAN will complain if valid address length passed to bind() is shorter
than sizeof(struct sockaddr_llc) bytes.

Signed-off-by: Tetsuo Handa &lt;penguin-kernel@I-love.SAKURA.ne.jp&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
KMSAN will complain if valid address length passed to bind() is shorter
than sizeof(struct sockaddr_llc) bytes.

Signed-off-by: Tetsuo Handa &lt;penguin-kernel@I-love.SAKURA.ne.jp&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>llc: do not use sk_eat_skb()</title>
<updated>2018-10-23T02:59:20+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2018-10-22T16:24:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=604d415e2bd642b7e02c80e719e0396b9d4a77a6'/>
<id>604d415e2bd642b7e02c80e719e0396b9d4a77a6</id>
<content type='text'>
syzkaller triggered a use-after-free [1], caused by a combination of
skb_get() in llc_conn_state_process() and usage of sk_eat_skb()

sk_eat_skb() is assuming the skb about to be freed is only used by
the current thread. TCP/DCCP stacks enforce this because current
thread holds the socket lock.

llc_conn_state_process() wants to make sure skb does not disappear,
and holds a reference on the skb it manipulates. But as soon as this
skb is added to socket receive queue, another thread can consume it.

This means that llc must use regular skb_unlink() and kfree_skb()
so that both producer and consumer can safely work on the same skb.

[1]
BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
BUG: KASAN: use-after-free in refcount_read include/linux/refcount.h:43 [inline]
BUG: KASAN: use-after-free in skb_unref include/linux/skbuff.h:967 [inline]
BUG: KASAN: use-after-free in kfree_skb+0xb7/0x580 net/core/skbuff.c:655
Read of size 4 at addr ffff8801d1f6fba4 by task ksoftirqd/1/18

CPU: 1 PID: 18 Comm: ksoftirqd/1 Not tainted 4.19.0-rc8+ #295
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c4/0x2b6 lib/dump_stack.c:113
 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
 kasan_check_read+0x11/0x20 mm/kasan/kasan.c:272
 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
 refcount_read include/linux/refcount.h:43 [inline]
 skb_unref include/linux/skbuff.h:967 [inline]
 kfree_skb+0xb7/0x580 net/core/skbuff.c:655
 llc_sap_state_process+0x9b/0x550 net/llc/llc_sap.c:224
 llc_sap_rcv+0x156/0x1f0 net/llc/llc_sap.c:297
 llc_sap_handler+0x65e/0xf80 net/llc/llc_sap.c:438
 llc_rcv+0x79e/0xe20 net/llc/llc_input.c:208
 __netif_receive_skb_one_core+0x14d/0x200 net/core/dev.c:4913
 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:5023
 process_backlog+0x218/0x6f0 net/core/dev.c:5829
 napi_poll net/core/dev.c:6249 [inline]
 net_rx_action+0x7c5/0x1950 net/core/dev.c:6315
 __do_softirq+0x30c/0xb03 kernel/softirq.c:292
 run_ksoftirqd+0x94/0x100 kernel/softirq.c:653
 smpboot_thread_fn+0x68b/0xa00 kernel/smpboot.c:164
 kthread+0x35a/0x420 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413

Allocated by task 18:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
 kmem_cache_alloc_node+0x144/0x730 mm/slab.c:3644
 __alloc_skb+0x119/0x770 net/core/skbuff.c:193
 alloc_skb include/linux/skbuff.h:995 [inline]
 llc_alloc_frame+0xbc/0x370 net/llc/llc_sap.c:54
 llc_station_ac_send_xid_r net/llc/llc_station.c:52 [inline]
 llc_station_rcv+0x1dc/0x1420 net/llc/llc_station.c:111
 llc_rcv+0xc32/0xe20 net/llc/llc_input.c:220
 __netif_receive_skb_one_core+0x14d/0x200 net/core/dev.c:4913
 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:5023
 process_backlog+0x218/0x6f0 net/core/dev.c:5829
 napi_poll net/core/dev.c:6249 [inline]
 net_rx_action+0x7c5/0x1950 net/core/dev.c:6315
 __do_softirq+0x30c/0xb03 kernel/softirq.c:292

Freed by task 16383:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kmem_cache_free+0x83/0x290 mm/slab.c:3756
 kfree_skbmem+0x154/0x230 net/core/skbuff.c:582
 __kfree_skb+0x1d/0x20 net/core/skbuff.c:642
 sk_eat_skb include/net/sock.h:2366 [inline]
 llc_ui_recvmsg+0xec2/0x1610 net/llc/af_llc.c:882
 sock_recvmsg_nosec net/socket.c:794 [inline]
 sock_recvmsg+0xd0/0x110 net/socket.c:801
 ___sys_recvmsg+0x2b6/0x680 net/socket.c:2278
 __sys_recvmmsg+0x303/0xb90 net/socket.c:2390
 do_sys_recvmmsg+0x181/0x1a0 net/socket.c:2466
 __do_sys_recvmmsg net/socket.c:2484 [inline]
 __se_sys_recvmmsg net/socket.c:2480 [inline]
 __x64_sys_recvmmsg+0xbe/0x150 net/socket.c:2480
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801d1f6fac0
 which belongs to the cache skbuff_head_cache of size 232
The buggy address is located 228 bytes inside of
 232-byte region [ffff8801d1f6fac0, ffff8801d1f6fba8)
The buggy address belongs to the page:
page:ffffea000747dbc0 count:1 mapcount:0 mapping:ffff8801d9be7680 index:0xffff8801d1f6fe80
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea0007346e88 ffffea000705b108 ffff8801d9be7680
raw: ffff8801d1f6fe80 ffff8801d1f6f0c0 000000010000000b 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d1f6fa80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
 ffff8801d1f6fb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
&gt;ffff8801d1f6fb80: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc
                               ^
 ffff8801d1f6fc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801d1f6fc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
syzkaller triggered a use-after-free [1], caused by a combination of
skb_get() in llc_conn_state_process() and usage of sk_eat_skb()

sk_eat_skb() is assuming the skb about to be freed is only used by
the current thread. TCP/DCCP stacks enforce this because current
thread holds the socket lock.

llc_conn_state_process() wants to make sure skb does not disappear,
and holds a reference on the skb it manipulates. But as soon as this
skb is added to socket receive queue, another thread can consume it.

This means that llc must use regular skb_unlink() and kfree_skb()
so that both producer and consumer can safely work on the same skb.

[1]
BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
BUG: KASAN: use-after-free in refcount_read include/linux/refcount.h:43 [inline]
BUG: KASAN: use-after-free in skb_unref include/linux/skbuff.h:967 [inline]
BUG: KASAN: use-after-free in kfree_skb+0xb7/0x580 net/core/skbuff.c:655
Read of size 4 at addr ffff8801d1f6fba4 by task ksoftirqd/1/18

CPU: 1 PID: 18 Comm: ksoftirqd/1 Not tainted 4.19.0-rc8+ #295
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c4/0x2b6 lib/dump_stack.c:113
 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
 kasan_check_read+0x11/0x20 mm/kasan/kasan.c:272
 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
 refcount_read include/linux/refcount.h:43 [inline]
 skb_unref include/linux/skbuff.h:967 [inline]
 kfree_skb+0xb7/0x580 net/core/skbuff.c:655
 llc_sap_state_process+0x9b/0x550 net/llc/llc_sap.c:224
 llc_sap_rcv+0x156/0x1f0 net/llc/llc_sap.c:297
 llc_sap_handler+0x65e/0xf80 net/llc/llc_sap.c:438
 llc_rcv+0x79e/0xe20 net/llc/llc_input.c:208
 __netif_receive_skb_one_core+0x14d/0x200 net/core/dev.c:4913
 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:5023
 process_backlog+0x218/0x6f0 net/core/dev.c:5829
 napi_poll net/core/dev.c:6249 [inline]
 net_rx_action+0x7c5/0x1950 net/core/dev.c:6315
 __do_softirq+0x30c/0xb03 kernel/softirq.c:292
 run_ksoftirqd+0x94/0x100 kernel/softirq.c:653
 smpboot_thread_fn+0x68b/0xa00 kernel/smpboot.c:164
 kthread+0x35a/0x420 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413

Allocated by task 18:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
 kmem_cache_alloc_node+0x144/0x730 mm/slab.c:3644
 __alloc_skb+0x119/0x770 net/core/skbuff.c:193
 alloc_skb include/linux/skbuff.h:995 [inline]
 llc_alloc_frame+0xbc/0x370 net/llc/llc_sap.c:54
 llc_station_ac_send_xid_r net/llc/llc_station.c:52 [inline]
 llc_station_rcv+0x1dc/0x1420 net/llc/llc_station.c:111
 llc_rcv+0xc32/0xe20 net/llc/llc_input.c:220
 __netif_receive_skb_one_core+0x14d/0x200 net/core/dev.c:4913
 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:5023
 process_backlog+0x218/0x6f0 net/core/dev.c:5829
 napi_poll net/core/dev.c:6249 [inline]
 net_rx_action+0x7c5/0x1950 net/core/dev.c:6315
 __do_softirq+0x30c/0xb03 kernel/softirq.c:292

Freed by task 16383:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kmem_cache_free+0x83/0x290 mm/slab.c:3756
 kfree_skbmem+0x154/0x230 net/core/skbuff.c:582
 __kfree_skb+0x1d/0x20 net/core/skbuff.c:642
 sk_eat_skb include/net/sock.h:2366 [inline]
 llc_ui_recvmsg+0xec2/0x1610 net/llc/af_llc.c:882
 sock_recvmsg_nosec net/socket.c:794 [inline]
 sock_recvmsg+0xd0/0x110 net/socket.c:801
 ___sys_recvmsg+0x2b6/0x680 net/socket.c:2278
 __sys_recvmmsg+0x303/0xb90 net/socket.c:2390
 do_sys_recvmmsg+0x181/0x1a0 net/socket.c:2466
 __do_sys_recvmmsg net/socket.c:2484 [inline]
 __se_sys_recvmmsg net/socket.c:2480 [inline]
 __x64_sys_recvmmsg+0xbe/0x150 net/socket.c:2480
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801d1f6fac0
 which belongs to the cache skbuff_head_cache of size 232
The buggy address is located 228 bytes inside of
 232-byte region [ffff8801d1f6fac0, ffff8801d1f6fba8)
The buggy address belongs to the page:
page:ffffea000747dbc0 count:1 mapcount:0 mapping:ffff8801d9be7680 index:0xffff8801d1f6fe80
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea0007346e88 ffffea000705b108 ffff8801d9be7680
raw: ffff8801d1f6fe80 ffff8801d1f6f0c0 000000010000000b 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d1f6fa80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
 ffff8801d1f6fb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
&gt;ffff8801d1f6fb80: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc
                               ^
 ffff8801d1f6fc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801d1f6fc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net</title>
<updated>2018-10-19T18:03:06+00:00</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2018-10-19T18:03:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2e2d6f0342be7f73a34526077fa96f42f0e8c661'/>
<id>2e2d6f0342be7f73a34526077fa96f42f0e8c661</id>
<content type='text'>
net/sched/cls_api.c has overlapping changes to a call to
nlmsg_parse(), one (from 'net') added rtm_tca_policy instead of NULL
to the 5th argument, and another (from 'net-next') added cb-&gt;extack
instead of NULL to the 6th argument.

net/ipv4/ipmr_base.c is a case of a bug fix in 'net' being done to
code which moved (to mr_table_dump)) in 'net-next'.  Thanks to David
Ahern for the heads up.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
net/sched/cls_api.c has overlapping changes to a call to
nlmsg_parse(), one (from 'net') added rtm_tca_policy instead of NULL
to the 5th argument, and another (from 'net-next') added cb-&gt;extack
instead of NULL to the 6th argument.

net/ipv4/ipmr_base.c is a case of a bug fix in 'net' being done to
code which moved (to mr_table_dump)) in 'net-next'.  Thanks to David
Ahern for the heads up.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>llc: set SOCK_RCU_FREE in llc_sap_add_socket()</title>
<updated>2018-10-16T05:01:37+00:00</updated>
<author>
<name>Cong Wang</name>
<email>xiyou.wangcong@gmail.com</email>
</author>
<published>2018-10-11T18:15:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5a8e7aea953bdb6d4da13aff6f1e7f9c62023499'/>
<id>5a8e7aea953bdb6d4da13aff6f1e7f9c62023499</id>
<content type='text'>
WHen an llc sock is added into the sk_laddr_hash of an llc_sap,
it is not marked with SOCK_RCU_FREE.

This causes that the sock could be freed while it is still being
read by __llc_lookup_established() with RCU read lock. sock is
refcounted, but with RCU read lock, nothing prevents the readers
getting a zero refcnt.

Fix it by setting SOCK_RCU_FREE in llc_sap_add_socket().

Reported-by: syzbot+11e05f04c15e03be5254@syzkaller.appspotmail.com
Signed-off-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
WHen an llc sock is added into the sk_laddr_hash of an llc_sap,
it is not marked with SOCK_RCU_FREE.

This causes that the sock could be freed while it is still being
read by __llc_lookup_established() with RCU read lock. sock is
refcounted, but with RCU read lock, nothing prevents the readers
getting a zero refcnt.

Fix it by setting SOCK_RCU_FREE in llc_sap_add_socket().

Reported-by: syzbot+11e05f04c15e03be5254@syzkaller.appspotmail.com
Signed-off-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>llc: avoid blocking in llc_sap_close()</title>
<updated>2018-09-13T16:04:58+00:00</updated>
<author>
<name>Cong Wang</name>
<email>xiyou.wangcong@gmail.com</email>
</author>
<published>2018-09-11T18:42:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=9708d2b5b7c648e8e0a40d11e8cea12f6277f33c'/>
<id>9708d2b5b7c648e8e0a40d11e8cea12f6277f33c</id>
<content type='text'>
llc_sap_close() is called by llc_sap_put() which
could be called in BH context in llc_rcv(). We can't
block in BH.

There is no reason to block it here, kfree_rcu() should
be sufficient.

Signed-off-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
llc_sap_close() is called by llc_sap_put() which
could be called in BH context in llc_rcv(). We can't
block in BH.

There is no reason to block it here, kfree_rcu() should
be sufficient.

Signed-off-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net</title>
<updated>2018-08-09T18:52:36+00:00</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2018-08-09T18:52:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a736e074680745faa5dc6be8dd3c58ad4850aab9'/>
<id>a736e074680745faa5dc6be8dd3c58ad4850aab9</id>
<content type='text'>
Overlapping changes in RXRPC, changing to ktime_get_seconds() whilst
adding some tracepoints.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Overlapping changes in RXRPC, changing to ktime_get_seconds() whilst
adding some tracepoints.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>llc: use refcount_inc_not_zero() for llc_sap_find()</title>
<updated>2018-08-07T22:54:00+00:00</updated>
<author>
<name>Cong Wang</name>
<email>xiyou.wangcong@gmail.com</email>
</author>
<published>2018-08-07T19:41:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0dcb82254d65f72333aa50ad626d1e9665ad093b'/>
<id>0dcb82254d65f72333aa50ad626d1e9665ad093b</id>
<content type='text'>
llc_sap_put() decreases the refcnt before deleting sap
from the global list. Therefore, there is a chance
llc_sap_find() could find a sap with zero refcnt
in this global list.

Close this race condition by checking if refcnt is zero
or not in llc_sap_find(), if it is zero then it is being
removed so we can just treat it as gone.

Reported-by: &lt;syzbot+278893f3f7803871f7ce@syzkaller.appspotmail.com&gt;
Signed-off-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
llc_sap_put() decreases the refcnt before deleting sap
from the global list. Therefore, there is a chance
llc_sap_find() could find a sap with zero refcnt
in this global list.

Close this race condition by checking if refcnt is zero
or not in llc_sap_find(), if it is zero then it is being
removed so we can just treat it as gone.

Reported-by: &lt;syzbot+278893f3f7803871f7ce@syzkaller.appspotmail.com&gt;
Signed-off-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
</feed>
