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* KASAN: use-after-free Read in ccid_hc_tx_delete
@ 2018-08-27 17:10 ` syzbot
  0 siblings, 0 replies; 13+ messages in thread
From: syzbot @ 2018-08-27 17:10 UTC (permalink / raw)
  To: davem, dccp, gerrit, linux-kernel, netdev, syzkaller-bugs

Hello,

syzbot found the following crash on:

HEAD commit:    aba16dc5cf93 Merge branch 'ida-4.19' of git://git.infradea..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1750d382400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=3b576e333ca31bb2
dashboard link: https://syzkaller.appspot.com/bug?extid=3967c1caf256f4d5aefe
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=119d007a400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+3967c1caf256f4d5aefe@syzkaller.appspotmail.com

8021q: adding VLAN 0 to HW filter on device team0
8021q: adding VLAN 0 to HW filter on device team0
8021q: adding VLAN 0 to HW filter on device team0
hrtimer: interrupt took 33823 ns
==================================================================
BUG: KASAN: use-after-free in ccid_hc_tx_delete+0xe0/0x100  
net/dccp/ccid.c:188
Read of size 8 at addr ffff8801b0726b40 by task syz-executor3/6567

CPU: 1 PID: 6567 Comm: syz-executor3 Not tainted 4.18.0+ #210
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
  <IRQ>
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
  print_address_description+0x6c/0x20b mm/kasan/report.c:256
  kasan_report_error mm/kasan/report.c:354 [inline]
  kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412
  __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
  ccid_hc_tx_delete+0xe0/0x100 net/dccp/ccid.c:188
  dccp_sk_destruct+0x3c/0x80 net/dccp/proto.c:181
  __sk_destruct+0x107/0xa60 net/core/sock.c:1560
  __rcu_reclaim kernel/rcu/rcu.h:236 [inline]
  rcu_do_batch kernel/rcu/tree.c:2576 [inline]
  invoke_rcu_callbacks kernel/rcu/tree.c:2880 [inline]
  __rcu_process_callbacks kernel/rcu/tree.c:2847 [inline]
  rcu_process_callbacks+0xf78/0x27c0 kernel/rcu/tree.c:2864
  __do_softirq+0x2eb/0xa74 kernel/softirq.c:292
  invoke_softirq kernel/softirq.c:372 [inline]
  irq_exit+0x1d6/0x210 kernel/softirq.c:412
  exiting_irq arch/x86/include/asm/apic.h:536 [inline]
  smp_apic_timer_interrupt+0x18e/0x6a0 arch/x86/kernel/apic/apic.c:1056
  apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:864
  </IRQ>
RIP: 0010:memset_erms+0x9/0x10 arch/x86/lib/memset_64.S:65
Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48  
ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 <f3> aa 4c 89 c8  
c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01
RSP: 0018:ffff8801b2aa75b0 EFLAGS: 00010246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: 00000000006080c0 RCX: 0000000000000240
RDX: 0000000000000800 RSI: 0000000000000000 RDI: ffff8801addbc880
RBP: ffff8801b2aa7630 R08: ffff8801d7642a80 R09: ffff8801addbc2c0
R10: ffff8801d7642240 R11: 0000000000000000 R12: ffff8801addbc2c0
R13: ffff8801dac00c40 R14: ffff8801dac00c40 R15: 00000000006080c0
  kmalloc include/linux/slab.h:513 [inline]
  kzalloc include/linux/slab.h:707 [inline]
  perf_event_alloc.part.93+0x1e2/0x33c0 kernel/events/core.c:9927
  perf_event_alloc kernel/events/core.c:10399 [inline]
  __do_sys_perf_event_open+0xa9c/0x2f30 kernel/events/core.c:10500
  __se_sys_perf_event_open kernel/events/core.c:10389 [inline]
  __x64_sys_perf_event_open+0xbe/0x150 kernel/events/core.c:10389
  do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457089
Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fc7df221c78 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007fc7df2226d4 RCX: 0000000000457089
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 000000002001d000
RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d3300 R14: 00000000004c8290 R15: 0000000000000000

Allocated by task 6568:
  save_stack+0x43/0xd0 mm/kasan/kasan.c:448
  set_track mm/kasan/kasan.c:460 [inline]
  kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
  kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
  kmem_cache_alloc+0x12e/0x710 mm/slab.c:3554
  ccid_new+0x25b/0x3e0 net/dccp/ccid.c:151
  dccp_hdlr_ccid+0x27/0x150 net/dccp/feat.c:44
  __dccp_feat_activate+0x184/0x270 net/dccp/feat.c:344
  dccp_feat_activate_values+0x3b6/0x839 net/dccp/feat.c:1538
  dccp_rcv_request_sent_state_process net/dccp/input.c:472 [inline]
  dccp_rcv_state_process+0x11dc/0x1a30 net/dccp/input.c:678
  dccp_v6_do_rcv+0x26f/0xb80 net/dccp/ipv6.c:638
  sk_backlog_rcv include/net/sock.h:931 [inline]
  __release_sock+0x12f/0x3a0 net/core/sock.c:2336
  release_sock+0xad/0x2c0 net/core/sock.c:2849
  inet_wait_for_connect net/ipv4/af_inet.c:588 [inline]
  __inet_stream_connect+0x61f/0x1160 net/ipv4/af_inet.c:680
  inet_stream_connect+0x58/0xa0 net/ipv4/af_inet.c:719
  __sys_connect+0x37d/0x4c0 net/socket.c:1662
  __do_sys_connect net/socket.c:1673 [inline]
  __se_sys_connect net/socket.c:1670 [inline]
  __x64_sys_connect+0x73/0xb0 net/socket.c:1670
  do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 6582:
  save_stack+0x43/0xd0 mm/kasan/kasan.c:448
  set_track mm/kasan/kasan.c:460 [inline]
  __kasan_slab_free+0x11a/0x170 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+0x86/0x280 mm/slab.c:3756
  ccid_hc_tx_delete+0xc3/0x100 net/dccp/ccid.c:190
  dccp_hdlr_ccid+0x7d/0x150 net/dccp/feat.c:53
  __dccp_feat_activate+0x184/0x270 net/dccp/feat.c:344
  dccp_feat_activate_values+0x3b6/0x839 net/dccp/feat.c:1538
  dccp_create_openreq_child+0x47a/0x620 net/dccp/minisocks.c:127
  dccp_v6_request_recv_sock+0x253/0x2040 net/dccp/ipv6.c:466
  dccp_check_req+0x46e/0x6c0 net/dccp/minisocks.c:196
  dccp_v6_rcv+0x88e/0x1d9c net/dccp/ipv6.c:744
  ip6_input_finish+0x407/0x1a40 net/ipv6/ip6_input.c:383
  NF_HOOK include/linux/netfilter.h:287 [inline]
  ip6_input+0xe9/0x600 net/ipv6/ip6_input.c:426
  dst_input include/net/dst.h:450 [inline]
  ip6_rcv_finish+0x17a/0x330 net/ipv6/ip6_input.c:76
  NF_HOOK include/linux/netfilter.h:287 [inline]
  ipv6_rcv+0x11e/0x650 net/ipv6/ip6_input.c:271
  __netif_receive_skb_one_core+0x14d/0x200 net/core/dev.c:4892
  __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:5002
  process_backlog+0x219/0x760 net/core/dev.c:5808
  napi_poll net/core/dev.c:6228 [inline]
  net_rx_action+0x799/0x1900 net/core/dev.c:6294
  __do_softirq+0x2eb/0xa74 kernel/softirq.c:292

The buggy address belongs to the object at ffff8801b0726b40
  which belongs to the cache ccid2_hc_tx_sock of size 1240
The buggy address is located 0 bytes inside of
  1240-byte region [ffff8801b0726b40, ffff8801b0727018)
The buggy address belongs to the page:
page:ffffea0006c1c980 count:1 mapcount:0 mapping:ffff8801cd8b6680 index:0x0  
compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffff8801cd8b3648 ffffea0006c1e308 ffff8801cd8b6680
raw: 0000000000000000 ffff8801b0726040 0000000100000005 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
  ffff8801b0726a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8801b0726a80: fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc
> ffff8801b0726b00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
                                            ^
  ffff8801b0726b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8801b0726c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with  
syzbot.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches

^ permalink raw reply	[flat|nested] 13+ messages in thread
* KASAN: use-after-free Read in ccid_hc_tx_delete
@ 2018-08-27 17:10 ` syzbot
  0 siblings, 0 replies; 13+ messages in thread
From: syzbot @ 2018-08-27 17:10 UTC (permalink / raw)
  To: dccp

Hello,

syzbot found the following crash on:

HEAD commit:    aba16dc5cf93 Merge branch 'ida-4.19' of git://git.infradea..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x\x1750d382400000
kernel config:  https://syzkaller.appspot.com/x/.config?x;576e333ca31bb2
dashboard link: https://syzkaller.appspot.com/bug?extid967c1caf256f4d5aefe
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x\x119d007a400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+3967c1caf256f4d5aefe@syzkaller.appspotmail.com

8021q: adding VLAN 0 to HW filter on device team0
8021q: adding VLAN 0 to HW filter on device team0
8021q: adding VLAN 0 to HW filter on device team0
hrtimer: interrupt took 33823 ns
=================================
BUG: KASAN: use-after-free in ccid_hc_tx_delete+0xe0/0x100  
net/dccp/ccid.c:188
Read of size 8 at addr ffff8801b0726b40 by task syz-executor3/6567

CPU: 1 PID: 6567 Comm: syz-executor3 Not tainted 4.18.0+ #210
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
  <IRQ>
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
  print_address_description+0x6c/0x20b mm/kasan/report.c:256
  kasan_report_error mm/kasan/report.c:354 [inline]
  kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412
  __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
  ccid_hc_tx_delete+0xe0/0x100 net/dccp/ccid.c:188
  dccp_sk_destruct+0x3c/0x80 net/dccp/proto.c:181
  __sk_destruct+0x107/0xa60 net/core/sock.c:1560
  __rcu_reclaim kernel/rcu/rcu.h:236 [inline]
  rcu_do_batch kernel/rcu/tree.c:2576 [inline]
  invoke_rcu_callbacks kernel/rcu/tree.c:2880 [inline]
  __rcu_process_callbacks kernel/rcu/tree.c:2847 [inline]
  rcu_process_callbacks+0xf78/0x27c0 kernel/rcu/tree.c:2864
  __do_softirq+0x2eb/0xa74 kernel/softirq.c:292
  invoke_softirq kernel/softirq.c:372 [inline]
  irq_exit+0x1d6/0x210 kernel/softirq.c:412
  exiting_irq arch/x86/include/asm/apic.h:536 [inline]
  smp_apic_timer_interrupt+0x18e/0x6a0 arch/x86/kernel/apic/apic.c:1056
  apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:864
  </IRQ>
RIP: 0010:memset_erms+0x9/0x10 arch/x86/lib/memset_64.S:65
Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48  
ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 <f3> aa 4c 89 c8  
c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01
RSP: 0018:ffff8801b2aa75b0 EFLAGS: 00010246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: 00000000006080c0 RCX: 0000000000000240
RDX: 0000000000000800 RSI: 0000000000000000 RDI: ffff8801addbc880
RBP: ffff8801b2aa7630 R08: ffff8801d7642a80 R09: ffff8801addbc2c0
R10: ffff8801d7642240 R11: 0000000000000000 R12: ffff8801addbc2c0
R13: ffff8801dac00c40 R14: ffff8801dac00c40 R15: 00000000006080c0
  kmalloc include/linux/slab.h:513 [inline]
  kzalloc include/linux/slab.h:707 [inline]
  perf_event_alloc.part.93+0x1e2/0x33c0 kernel/events/core.c:9927
  perf_event_alloc kernel/events/core.c:10399 [inline]
  __do_sys_perf_event_open+0xa9c/0x2f30 kernel/events/core.c:10500
  __se_sys_perf_event_open kernel/events/core.c:10389 [inline]
  __x64_sys_perf_event_open+0xbe/0x150 kernel/events/core.c:10389
  do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457089
Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fc7df221c78 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007fc7df2226d4 RCX: 0000000000457089
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 000000002001d000
RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d3300 R14: 00000000004c8290 R15: 0000000000000000

Allocated by task 6568:
  save_stack+0x43/0xd0 mm/kasan/kasan.c:448
  set_track mm/kasan/kasan.c:460 [inline]
  kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
  kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
  kmem_cache_alloc+0x12e/0x710 mm/slab.c:3554
  ccid_new+0x25b/0x3e0 net/dccp/ccid.c:151
  dccp_hdlr_ccid+0x27/0x150 net/dccp/feat.c:44
  __dccp_feat_activate+0x184/0x270 net/dccp/feat.c:344
  dccp_feat_activate_values+0x3b6/0x839 net/dccp/feat.c:1538
  dccp_rcv_request_sent_state_process net/dccp/input.c:472 [inline]
  dccp_rcv_state_process+0x11dc/0x1a30 net/dccp/input.c:678
  dccp_v6_do_rcv+0x26f/0xb80 net/dccp/ipv6.c:638
  sk_backlog_rcv include/net/sock.h:931 [inline]
  __release_sock+0x12f/0x3a0 net/core/sock.c:2336
  release_sock+0xad/0x2c0 net/core/sock.c:2849
  inet_wait_for_connect net/ipv4/af_inet.c:588 [inline]
  __inet_stream_connect+0x61f/0x1160 net/ipv4/af_inet.c:680
  inet_stream_connect+0x58/0xa0 net/ipv4/af_inet.c:719
  __sys_connect+0x37d/0x4c0 net/socket.c:1662
  __do_sys_connect net/socket.c:1673 [inline]
  __se_sys_connect net/socket.c:1670 [inline]
  __x64_sys_connect+0x73/0xb0 net/socket.c:1670
  do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 6582:
  save_stack+0x43/0xd0 mm/kasan/kasan.c:448
  set_track mm/kasan/kasan.c:460 [inline]
  __kasan_slab_free+0x11a/0x170 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+0x86/0x280 mm/slab.c:3756
  ccid_hc_tx_delete+0xc3/0x100 net/dccp/ccid.c:190
  dccp_hdlr_ccid+0x7d/0x150 net/dccp/feat.c:53
  __dccp_feat_activate+0x184/0x270 net/dccp/feat.c:344
  dccp_feat_activate_values+0x3b6/0x839 net/dccp/feat.c:1538
  dccp_create_openreq_child+0x47a/0x620 net/dccp/minisocks.c:127
  dccp_v6_request_recv_sock+0x253/0x2040 net/dccp/ipv6.c:466
  dccp_check_req+0x46e/0x6c0 net/dccp/minisocks.c:196
  dccp_v6_rcv+0x88e/0x1d9c net/dccp/ipv6.c:744
  ip6_input_finish+0x407/0x1a40 net/ipv6/ip6_input.c:383
  NF_HOOK include/linux/netfilter.h:287 [inline]
  ip6_input+0xe9/0x600 net/ipv6/ip6_input.c:426
  dst_input include/net/dst.h:450 [inline]
  ip6_rcv_finish+0x17a/0x330 net/ipv6/ip6_input.c:76
  NF_HOOK include/linux/netfilter.h:287 [inline]
  ipv6_rcv+0x11e/0x650 net/ipv6/ip6_input.c:271
  __netif_receive_skb_one_core+0x14d/0x200 net/core/dev.c:4892
  __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:5002
  process_backlog+0x219/0x760 net/core/dev.c:5808
  napi_poll net/core/dev.c:6228 [inline]
  net_rx_action+0x799/0x1900 net/core/dev.c:6294
  __do_softirq+0x2eb/0xa74 kernel/softirq.c:292

The buggy address belongs to the object at ffff8801b0726b40
  which belongs to the cache ccid2_hc_tx_sock of size 1240
The buggy address is located 0 bytes inside of
  1240-byte region [ffff8801b0726b40, ffff8801b0727018)
The buggy address belongs to the page:
page:ffffea0006c1c980 count:1 mapcount:0 mapping:ffff8801cd8b6680 index:0x0  
compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffff8801cd8b3648 ffffea0006c1e308 ffff8801cd8b6680
raw: 0000000000000000 ffff8801b0726040 0000000100000005 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
  ffff8801b0726a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8801b0726a80: fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc
> ffff8801b0726b00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
                                            ^
  ffff8801b0726b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8801b0726c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
=================================


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with  
syzbot.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches

^ permalink raw reply	[flat|nested] 13+ messages in thread
* Re: KASAN: use-after-free Read in ccid_hc_tx_delete
@ 2018-12-14 21:58   ` syzbot
  0 siblings, 0 replies; 13+ messages in thread
From: syzbot @ 2018-12-14 21:58 UTC (permalink / raw)
  To: davem, dccp, gerrit, linux-kernel, netdev, syzkaller-bugs

syzbot has found a reproducer for the following crash on:

HEAD commit:    eb6cf9f8cb9d Merge tag 'arm64-fixes' of git://git.kernel.o..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11a09b6d400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c8970c89a0efbb23
dashboard link: https://syzkaller.appspot.com/bug?extid=3967c1caf256f4d5aefe
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
userspace arch: i386
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12a4895d400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1271cf05400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+3967c1caf256f4d5aefe@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in ccid_hc_tx_delete+0xe0/0x100  
net/dccp/ccid.c:188
Read of size 8 at addr ffff8881bdce7980 by task syz-executor384/6286

CPU: 1 PID: 6286 Comm: syz-executor384 Not tainted 4.20.0-rc6+ #276
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
  <IRQ>
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x244/0x39d lib/dump_stack.c:113
  print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256
  kasan_report_error mm/kasan/report.c:354 [inline]
  kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412
  __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
  ccid_hc_tx_delete+0xe0/0x100 net/dccp/ccid.c:188
  dccp_hdlr_ccid+0x7d/0x150 net/dccp/feat.c:53
  __dccp_feat_activate+0x188/0x280 net/dccp/feat.c:344
  dccp_feat_activate_values+0x3c1/0x80a net/dccp/feat.c:1538
  dccp_create_openreq_child+0x47a/0x630 net/dccp/minisocks.c:127
  dccp_v6_request_recv_sock+0x278/0x2020 net/dccp/ipv6.c:466
  dccp_check_req+0x47d/0x6d0 net/dccp/minisocks.c:196
  dccp_v6_rcv+0x874/0x1ce9 net/dccp/ipv6.c:744
  ip6_input_finish+0x3fc/0x1aa0 net/ipv6/ip6_input.c:384
  NF_HOOK include/linux/netfilter.h:289 [inline]
  ip6_input+0xe9/0x600 net/ipv6/ip6_input.c:427
  dst_input include/net/dst.h:450 [inline]
  ip6_rcv_finish+0x17a/0x330 net/ipv6/ip6_input.c:76
  NF_HOOK include/linux/netfilter.h:289 [inline]
  ipv6_rcv+0x115/0x640 net/ipv6/ip6_input.c:272
  __netif_receive_skb_one_core+0x14d/0x200 net/core/dev.c:4946
  __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:5056
  process_backlog+0x24e/0x7a0 net/core/dev.c:5864
  napi_poll net/core/dev.c:6287 [inline]
  net_rx_action+0x7fa/0x19b0 net/core/dev.c:6353
  __do_softirq+0x308/0xb7e kernel/softirq.c:292
  do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1027
  </IRQ>
  do_softirq.part.14+0x126/0x160 kernel/softirq.c:337
  do_softirq kernel/softirq.c:329 [inline]
  __local_bh_enable_ip+0x21d/0x260 kernel/softirq.c:189
  local_bh_enable include/linux/bottom_half.h:32 [inline]
  rcu_read_unlock_bh include/linux/rcupdate.h:696 [inline]
  ip6_finish_output2+0xcef/0x2940 net/ipv6/ip6_output.c:121
  ip6_finish_output+0x58c/0xc60 net/ipv6/ip6_output.c:154
  NF_HOOK_COND include/linux/netfilter.h:278 [inline]
  ip6_output+0x232/0x9d0 net/ipv6/ip6_output.c:171
  dst_output include/net/dst.h:444 [inline]
  NF_HOOK include/linux/netfilter.h:289 [inline]
  ip6_xmit+0xf1c/0x2510 net/ipv6/ip6_output.c:275
  inet6_csk_xmit+0x375/0x630 net/ipv6/inet6_connection_sock.c:139
  dccp_transmit_skb+0x98c/0x12e0 net/dccp/output.c:142
  dccp_send_ack+0x1d9/0x360 net/dccp/output.c:595
  dccp_rcv_request_sent_state_process net/dccp/input.c:501 [inline]
  dccp_rcv_state_process+0x152e/0x1b7e net/dccp/input.c:680
  dccp_v6_do_rcv+0x271/0xbf0 net/dccp/ipv6.c:638
  sk_backlog_rcv include/net/sock.h:932 [inline]
  __release_sock+0x12f/0x3a0 net/core/sock.c:2276
  release_sock+0xad/0x2c0 net/core/sock.c:2789
  inet_wait_for_connect net/ipv4/af_inet.c:588 [inline]
  __inet_stream_connect+0x641/0x1150 net/ipv4/af_inet.c:680
  inet_stream_connect+0x58/0xa0 net/ipv4/af_inet.c:719
  __sys_connect+0x37d/0x4c0 net/socket.c:1664
  __do_sys_connect net/socket.c:1675 [inline]
  __se_sys_connect net/socket.c:1672 [inline]
  __ia32_sys_connect+0x72/0xb0 net/socket.c:1672
  do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline]
  do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397
  entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f22a29
Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90  
90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90  
90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f7edc1fc EFLAGS: 00000293 ORIG_RAX: 000000000000016a
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020419000
RDX: 000000000000001c RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00000000003d0f00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 6269:
  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+0x12e/0x730 mm/slab.c:3554
  ccid_new+0x25b/0x3e0 net/dccp/ccid.c:151
  dccp_hdlr_ccid+0x27/0x150 net/dccp/feat.c:44
  __dccp_feat_activate+0x188/0x280 net/dccp/feat.c:344
  dccp_feat_activate_values+0x3c1/0x80a net/dccp/feat.c:1538
  dccp_rcv_request_sent_state_process net/dccp/input.c:472 [inline]
  dccp_rcv_state_process+0x1320/0x1b7e net/dccp/input.c:680
  dccp_v6_do_rcv+0x271/0xbf0 net/dccp/ipv6.c:638
  sk_backlog_rcv include/net/sock.h:932 [inline]
  __release_sock+0x12f/0x3a0 net/core/sock.c:2276
  release_sock+0xad/0x2c0 net/core/sock.c:2789
  inet_wait_for_connect net/ipv4/af_inet.c:588 [inline]
  __inet_stream_connect+0x641/0x1150 net/ipv4/af_inet.c:680
  inet_stream_connect+0x58/0xa0 net/ipv4/af_inet.c:719
  __sys_connect+0x37d/0x4c0 net/socket.c:1664
  __do_sys_connect net/socket.c:1675 [inline]
  __se_sys_connect net/socket.c:1672 [inline]
  __ia32_sys_connect+0x72/0xb0 net/socket.c:1672
  do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline]
  do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397
  entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

Freed by task 6283:
  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:3760
  ccid_hc_tx_delete+0xc3/0x100 net/dccp/ccid.c:190
  dccp_hdlr_ccid+0x7d/0x150 net/dccp/feat.c:53
  __dccp_feat_activate+0x188/0x280 net/dccp/feat.c:344
  dccp_feat_activate_values+0x3c1/0x80a net/dccp/feat.c:1538
  dccp_create_openreq_child+0x47a/0x630 net/dccp/minisocks.c:127
  dccp_v6_request_recv_sock+0x278/0x2020 net/dccp/ipv6.c:466
  dccp_check_req+0x47d/0x6d0 net/dccp/minisocks.c:196
  dccp_v6_rcv+0x874/0x1ce9 net/dccp/ipv6.c:744
  ip6_input_finish+0x3fc/0x1aa0 net/ipv6/ip6_input.c:384
  NF_HOOK include/linux/netfilter.h:289 [inline]
  ip6_input+0xe9/0x600 net/ipv6/ip6_input.c:427
  dst_input include/net/dst.h:450 [inline]
  ip6_rcv_finish+0x17a/0x330 net/ipv6/ip6_input.c:76
  NF_HOOK include/linux/netfilter.h:289 [inline]
  ipv6_rcv+0x115/0x640 net/ipv6/ip6_input.c:272
  __netif_receive_skb_one_core+0x14d/0x200 net/core/dev.c:4946
  __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:5056
  process_backlog+0x24e/0x7a0 net/core/dev.c:5864
  napi_poll net/core/dev.c:6287 [inline]
  net_rx_action+0x7fa/0x19b0 net/core/dev.c:6353
  __do_softirq+0x308/0xb7e kernel/softirq.c:292

The buggy address belongs to the object at ffff8881bdce7980
  which belongs to the cache ccid2_hc_tx_sock of size 1240
The buggy address is located 0 bytes inside of
  1240-byte region [ffff8881bdce7980, ffff8881bdce7e58)
The buggy address belongs to the page:
page:ffffea0006f73980 count:1 mapcount:0 mapping:ffff8881c5c76680 index:0x0  
compound_mapcount: 0
flags: 0x2fffc0000010200(slab|head)
raw: 02fffc0000010200 ffffea0006f71108 ffffea0006f73908 ffff8881c5c76680
raw: 0000000000000000 ffff8881bdce6380 0000000100000005 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
  ffff8881bdce7880: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
  ffff8881bdce7900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> ffff8881bdce7980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                    ^
  ffff8881bdce7a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8881bdce7a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


^ permalink raw reply	[flat|nested] 13+ messages in thread
* Re: KASAN: use-after-free Read in ccid_hc_tx_delete
@ 2018-12-14 21:58   ` syzbot
  0 siblings, 0 replies; 13+ messages in thread
From: syzbot @ 2018-12-14 21:58 UTC (permalink / raw)
  To: dccp

syzbot has found a reproducer for the following crash on:

HEAD commit:    eb6cf9f8cb9d Merge tag 'arm64-fixes' of git://git.kernel.o..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x\x11a09b6d400000
kernel config:  https://syzkaller.appspot.com/x/.config?x»970c89a0efbb23
dashboard link: https://syzkaller.appspot.com/bug?extid967c1caf256f4d5aefe
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
userspace arch: i386
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x\x12a4895d400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x\x1271cf05400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+3967c1caf256f4d5aefe@syzkaller.appspotmail.com

=================================
BUG: KASAN: use-after-free in ccid_hc_tx_delete+0xe0/0x100  
net/dccp/ccid.c:188
Read of size 8 at addr ffff8881bdce7980 by task syz-executor384/6286

CPU: 1 PID: 6286 Comm: syz-executor384 Not tainted 4.20.0-rc6+ #276
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
  <IRQ>
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x244/0x39d lib/dump_stack.c:113
  print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256
  kasan_report_error mm/kasan/report.c:354 [inline]
  kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412
  __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
  ccid_hc_tx_delete+0xe0/0x100 net/dccp/ccid.c:188
  dccp_hdlr_ccid+0x7d/0x150 net/dccp/feat.c:53
  __dccp_feat_activate+0x188/0x280 net/dccp/feat.c:344
  dccp_feat_activate_values+0x3c1/0x80a net/dccp/feat.c:1538
  dccp_create_openreq_child+0x47a/0x630 net/dccp/minisocks.c:127
  dccp_v6_request_recv_sock+0x278/0x2020 net/dccp/ipv6.c:466
  dccp_check_req+0x47d/0x6d0 net/dccp/minisocks.c:196
  dccp_v6_rcv+0x874/0x1ce9 net/dccp/ipv6.c:744
  ip6_input_finish+0x3fc/0x1aa0 net/ipv6/ip6_input.c:384
  NF_HOOK include/linux/netfilter.h:289 [inline]
  ip6_input+0xe9/0x600 net/ipv6/ip6_input.c:427
  dst_input include/net/dst.h:450 [inline]
  ip6_rcv_finish+0x17a/0x330 net/ipv6/ip6_input.c:76
  NF_HOOK include/linux/netfilter.h:289 [inline]
  ipv6_rcv+0x115/0x640 net/ipv6/ip6_input.c:272
  __netif_receive_skb_one_core+0x14d/0x200 net/core/dev.c:4946
  __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:5056
  process_backlog+0x24e/0x7a0 net/core/dev.c:5864
  napi_poll net/core/dev.c:6287 [inline]
  net_rx_action+0x7fa/0x19b0 net/core/dev.c:6353
  __do_softirq+0x308/0xb7e kernel/softirq.c:292
  do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1027
  </IRQ>
  do_softirq.part.14+0x126/0x160 kernel/softirq.c:337
  do_softirq kernel/softirq.c:329 [inline]
  __local_bh_enable_ip+0x21d/0x260 kernel/softirq.c:189
  local_bh_enable include/linux/bottom_half.h:32 [inline]
  rcu_read_unlock_bh include/linux/rcupdate.h:696 [inline]
  ip6_finish_output2+0xcef/0x2940 net/ipv6/ip6_output.c:121
  ip6_finish_output+0x58c/0xc60 net/ipv6/ip6_output.c:154
  NF_HOOK_COND include/linux/netfilter.h:278 [inline]
  ip6_output+0x232/0x9d0 net/ipv6/ip6_output.c:171
  dst_output include/net/dst.h:444 [inline]
  NF_HOOK include/linux/netfilter.h:289 [inline]
  ip6_xmit+0xf1c/0x2510 net/ipv6/ip6_output.c:275
  inet6_csk_xmit+0x375/0x630 net/ipv6/inet6_connection_sock.c:139
  dccp_transmit_skb+0x98c/0x12e0 net/dccp/output.c:142
  dccp_send_ack+0x1d9/0x360 net/dccp/output.c:595
  dccp_rcv_request_sent_state_process net/dccp/input.c:501 [inline]
  dccp_rcv_state_process+0x152e/0x1b7e net/dccp/input.c:680
  dccp_v6_do_rcv+0x271/0xbf0 net/dccp/ipv6.c:638
  sk_backlog_rcv include/net/sock.h:932 [inline]
  __release_sock+0x12f/0x3a0 net/core/sock.c:2276
  release_sock+0xad/0x2c0 net/core/sock.c:2789
  inet_wait_for_connect net/ipv4/af_inet.c:588 [inline]
  __inet_stream_connect+0x641/0x1150 net/ipv4/af_inet.c:680
  inet_stream_connect+0x58/0xa0 net/ipv4/af_inet.c:719
  __sys_connect+0x37d/0x4c0 net/socket.c:1664
  __do_sys_connect net/socket.c:1675 [inline]
  __se_sys_connect net/socket.c:1672 [inline]
  __ia32_sys_connect+0x72/0xb0 net/socket.c:1672
  do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline]
  do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397
  entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f22a29
Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90  
90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90  
90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f7edc1fc EFLAGS: 00000293 ORIG_RAX: 000000000000016a
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020419000
RDX: 000000000000001c RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00000000003d0f00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 6269:
  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+0x12e/0x730 mm/slab.c:3554
  ccid_new+0x25b/0x3e0 net/dccp/ccid.c:151
  dccp_hdlr_ccid+0x27/0x150 net/dccp/feat.c:44
  __dccp_feat_activate+0x188/0x280 net/dccp/feat.c:344
  dccp_feat_activate_values+0x3c1/0x80a net/dccp/feat.c:1538
  dccp_rcv_request_sent_state_process net/dccp/input.c:472 [inline]
  dccp_rcv_state_process+0x1320/0x1b7e net/dccp/input.c:680
  dccp_v6_do_rcv+0x271/0xbf0 net/dccp/ipv6.c:638
  sk_backlog_rcv include/net/sock.h:932 [inline]
  __release_sock+0x12f/0x3a0 net/core/sock.c:2276
  release_sock+0xad/0x2c0 net/core/sock.c:2789
  inet_wait_for_connect net/ipv4/af_inet.c:588 [inline]
  __inet_stream_connect+0x641/0x1150 net/ipv4/af_inet.c:680
  inet_stream_connect+0x58/0xa0 net/ipv4/af_inet.c:719
  __sys_connect+0x37d/0x4c0 net/socket.c:1664
  __do_sys_connect net/socket.c:1675 [inline]
  __se_sys_connect net/socket.c:1672 [inline]
  __ia32_sys_connect+0x72/0xb0 net/socket.c:1672
  do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline]
  do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397
  entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

Freed by task 6283:
  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:3760
  ccid_hc_tx_delete+0xc3/0x100 net/dccp/ccid.c:190
  dccp_hdlr_ccid+0x7d/0x150 net/dccp/feat.c:53
  __dccp_feat_activate+0x188/0x280 net/dccp/feat.c:344
  dccp_feat_activate_values+0x3c1/0x80a net/dccp/feat.c:1538
  dccp_create_openreq_child+0x47a/0x630 net/dccp/minisocks.c:127
  dccp_v6_request_recv_sock+0x278/0x2020 net/dccp/ipv6.c:466
  dccp_check_req+0x47d/0x6d0 net/dccp/minisocks.c:196
  dccp_v6_rcv+0x874/0x1ce9 net/dccp/ipv6.c:744
  ip6_input_finish+0x3fc/0x1aa0 net/ipv6/ip6_input.c:384
  NF_HOOK include/linux/netfilter.h:289 [inline]
  ip6_input+0xe9/0x600 net/ipv6/ip6_input.c:427
  dst_input include/net/dst.h:450 [inline]
  ip6_rcv_finish+0x17a/0x330 net/ipv6/ip6_input.c:76
  NF_HOOK include/linux/netfilter.h:289 [inline]
  ipv6_rcv+0x115/0x640 net/ipv6/ip6_input.c:272
  __netif_receive_skb_one_core+0x14d/0x200 net/core/dev.c:4946
  __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:5056
  process_backlog+0x24e/0x7a0 net/core/dev.c:5864
  napi_poll net/core/dev.c:6287 [inline]
  net_rx_action+0x7fa/0x19b0 net/core/dev.c:6353
  __do_softirq+0x308/0xb7e kernel/softirq.c:292

The buggy address belongs to the object at ffff8881bdce7980
  which belongs to the cache ccid2_hc_tx_sock of size 1240
The buggy address is located 0 bytes inside of
  1240-byte region [ffff8881bdce7980, ffff8881bdce7e58)
The buggy address belongs to the page:
page:ffffea0006f73980 count:1 mapcount:0 mapping:ffff8881c5c76680 index:0x0  
compound_mapcount: 0
flags: 0x2fffc0000010200(slab|head)
raw: 02fffc0000010200 ffffea0006f71108 ffffea0006f73908 ffff8881c5c76680
raw: 0000000000000000 ffff8881bdce6380 0000000100000005 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
  ffff8881bdce7880: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
  ffff8881bdce7900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> ffff8881bdce7980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                    ^
  ffff8881bdce7a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8881bdce7a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
=================================

^ permalink raw reply	[flat|nested] 13+ messages in thread
* Re: KASAN: use-after-free Read in ccid_hc_tx_delete
  2018-08-27 17:10 ` syzbot
  (?)
@ 2019-11-21 15:00   ` syzbot
  -1 siblings, 0 replies; 13+ messages in thread
From: syzbot @ 2019-11-21 15:00 UTC (permalink / raw)
  To: alsa-devel, dan.carpenter, davem, dccp, gerrit, linux-kernel,
	netdev, perex, syzkaller-bugs, tiwai, tiwai

syzbot has bisected this bug to:

commit f04684b4d85d6371126f476d3268ebf6a0bd57cf
Author: Dan Carpenter <dan.carpenter@oracle.com>
Date:   Thu Jun 21 08:07:21 2018 +0000

     ALSA: lx6464es: Missing error code in snd_lx6464es_create()

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=10dd11cae00000
start commit:   eb6cf9f8 Merge tag 'arm64-fixes' of git://git.kernel.org/p..
git tree:       upstream
final crash:    https://syzkaller.appspot.com/x/report.txt?x=12dd11cae00000
console output: https://syzkaller.appspot.com/x/log.txt?x=14dd11cae00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c8970c89a0efbb23
dashboard link: https://syzkaller.appspot.com/bug?extid=3967c1caf256f4d5aefe
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11022ccd400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=124581db400000

Reported-by: syzbot+3967c1caf256f4d5aefe@syzkaller.appspotmail.com
Fixes: f04684b4d85d ("ALSA: lx6464es: Missing error code in  
snd_lx6464es_create()")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

^ permalink raw reply	[flat|nested] 13+ messages in thread
* Re: [alsa-devel] KASAN: use-after-free Read in ccid_hc_tx_delete
@ 2019-11-21 15:00   ` syzbot
  0 siblings, 0 replies; 13+ messages in thread
From: syzbot @ 2019-11-21 15:00 UTC (permalink / raw)
  To: alsa-devel, dan.carpenter, davem, dccp, gerrit, linux-kernel,
	netdev, perex, syzkaller-bugs, tiwai, tiwai

syzbot has bisected this bug to:

commit f04684b4d85d6371126f476d3268ebf6a0bd57cf
Author: Dan Carpenter <dan.carpenter@oracle.com>
Date:   Thu Jun 21 08:07:21 2018 +0000

     ALSA: lx6464es: Missing error code in snd_lx6464es_create()

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=10dd11cae00000
start commit:   eb6cf9f8 Merge tag 'arm64-fixes' of git://git.kernel.org/p..
git tree:       upstream
final crash:    https://syzkaller.appspot.com/x/report.txt?x=12dd11cae00000
console output: https://syzkaller.appspot.com/x/log.txt?x=14dd11cae00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c8970c89a0efbb23
dashboard link: https://syzkaller.appspot.com/bug?extid=3967c1caf256f4d5aefe
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11022ccd400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=124581db400000

Reported-by: syzbot+3967c1caf256f4d5aefe@syzkaller.appspotmail.com
Fixes: f04684b4d85d ("ALSA: lx6464es: Missing error code in  
snd_lx6464es_create()")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection
_______________________________________________
Alsa-devel mailing list
Alsa-devel@alsa-project.org
https://mailman.alsa-project.org/mailman/listinfo/alsa-devel

^ permalink raw reply	[flat|nested] 13+ messages in thread
* Re: KASAN: use-after-free Read in ccid_hc_tx_delete
@ 2019-11-21 15:00   ` syzbot
  0 siblings, 0 replies; 13+ messages in thread
From: syzbot @ 2019-11-21 15:00 UTC (permalink / raw)
  To: dccp

syzbot has bisected this bug to:

commit f04684b4d85d6371126f476d3268ebf6a0bd57cf
Author: Dan Carpenter <dan.carpenter@oracle.com>
Date:   Thu Jun 21 08:07:21 2018 +0000

     ALSA: lx6464es: Missing error code in snd_lx6464es_create()

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x\x10dd11cae00000
start commit:   eb6cf9f8 Merge tag 'arm64-fixes' of git://git.kernel.org/p..
git tree:       upstream
final crash:    https://syzkaller.appspot.com/x/report.txt?x\x12dd11cae00000
console output: https://syzkaller.appspot.com/x/log.txt?x\x14dd11cae00000
kernel config:  https://syzkaller.appspot.com/x/.config?x»970c89a0efbb23
dashboard link: https://syzkaller.appspot.com/bug?extid967c1caf256f4d5aefe
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x\x11022ccd400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x\x124581db400000

Reported-by: syzbot+3967c1caf256f4d5aefe@syzkaller.appspotmail.com
Fixes: f04684b4d85d ("ALSA: lx6464es: Missing error code in  
snd_lx6464es_create()")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

^ permalink raw reply	[flat|nested] 13+ messages in thread
* Re: KASAN: use-after-free Read in ccid_hc_tx_delete
  2019-11-21 15:00   ` [alsa-devel] " syzbot
  (?)
@ 2019-11-21 20:14     ` Dan Carpenter
  -1 siblings, 0 replies; 13+ messages in thread
From: Dan Carpenter @ 2019-11-21 20:14 UTC (permalink / raw)
  To: syzbot
  Cc: alsa-devel, davem, dccp, gerrit, linux-kernel, netdev, perex,
	syzkaller-bugs, tiwai, tiwai, Eric Dumazet

On Thu, Nov 21, 2019 at 07:00:00AM -0800, syzbot wrote:
> syzbot has bisected this bug to:
> 
> commit f04684b4d85d6371126f476d3268ebf6a0bd57cf
> Author: Dan Carpenter <dan.carpenter@oracle.com>
> Date:   Thu Jun 21 08:07:21 2018 +0000
> 
>     ALSA: lx6464es: Missing error code in snd_lx6464es_create()
> 
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=10dd11cae00000
> start commit:   eb6cf9f8 Merge tag 'arm64-fixes' of git://git.kernel.org/p..
> git tree:       upstream
> final crash:    https://syzkaller.appspot.com/x/report.txt?x=12dd11cae00000
> console output: https://syzkaller.appspot.com/x/log.txt?x=14dd11cae00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=c8970c89a0efbb23
> dashboard link: https://syzkaller.appspot.com/bug?extid=3967c1caf256f4d5aefe
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11022ccd400000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=124581db400000
> 
> Reported-by: syzbot+3967c1caf256f4d5aefe@syzkaller.appspotmail.com
> Fixes: f04684b4d85d ("ALSA: lx6464es: Missing error code in
> snd_lx6464es_create()")
> 
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection

This crash isn't related to my commit, it's seems something specific to
DCCP.

My guess is that the fix is probably something like this.  The old sk
and the new sk re-use the same newdp->dccps_hc_rx/tx_ccid pointers.
The first sk destructor frees it and that causes a use after free when
the second destructor tries to free it.

But I don't know DCCP code at all so I might be totally off and I
haven't tested this at all...  It was just easier to write a patch than
to try to explain in words.  Maybe we should clone the ccid instead of
setting it to NULL.  Or I might be completely wrong.

---
 net/dccp/minisocks.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
index 25187528c308..4cbfcccbbbbb 100644
--- a/net/dccp/minisocks.c
+++ b/net/dccp/minisocks.c
@@ -98,6 +98,8 @@ struct sock *dccp_create_openreq_child(const struct sock *sk,
 		newdp->dccps_timestamp_echo = dreq->dreq_timestamp_echo;
 		newdp->dccps_timestamp_time = dreq->dreq_timestamp_time;
 		newicsk->icsk_rto	    = DCCP_TIMEOUT_INIT;
+		newdp->dccps_hc_rx_ccid     = NULL;
+		newdp->dccps_hc_tx_ccid     = NULL;
 
 		INIT_LIST_HEAD(&newdp->dccps_featneg);
 		/*
-- 
2.11.0





^ permalink raw reply related	[flat|nested] 13+ messages in thread
* Re: [alsa-devel] KASAN: use-after-free Read in ccid_hc_tx_delete
@ 2019-11-21 20:14     ` Dan Carpenter
  0 siblings, 0 replies; 13+ messages in thread
From: Dan Carpenter @ 2019-11-21 20:14 UTC (permalink / raw)
  To: syzbot
  Cc: gerrit, alsa-devel, dccp, tiwai, netdev, tiwai, syzkaller-bugs,
	linux-kernel, Eric Dumazet, davem

On Thu, Nov 21, 2019 at 07:00:00AM -0800, syzbot wrote:
> syzbot has bisected this bug to:
> 
> commit f04684b4d85d6371126f476d3268ebf6a0bd57cf
> Author: Dan Carpenter <dan.carpenter@oracle.com>
> Date:   Thu Jun 21 08:07:21 2018 +0000
> 
>     ALSA: lx6464es: Missing error code in snd_lx6464es_create()
> 
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=10dd11cae00000
> start commit:   eb6cf9f8 Merge tag 'arm64-fixes' of git://git.kernel.org/p..
> git tree:       upstream
> final crash:    https://syzkaller.appspot.com/x/report.txt?x=12dd11cae00000
> console output: https://syzkaller.appspot.com/x/log.txt?x=14dd11cae00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=c8970c89a0efbb23
> dashboard link: https://syzkaller.appspot.com/bug?extid=3967c1caf256f4d5aefe
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11022ccd400000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=124581db400000
> 
> Reported-by: syzbot+3967c1caf256f4d5aefe@syzkaller.appspotmail.com
> Fixes: f04684b4d85d ("ALSA: lx6464es: Missing error code in
> snd_lx6464es_create()")
> 
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection

This crash isn't related to my commit, it's seems something specific to
DCCP.

My guess is that the fix is probably something like this.  The old sk
and the new sk re-use the same newdp->dccps_hc_rx/tx_ccid pointers.
The first sk destructor frees it and that causes a use after free when
the second destructor tries to free it.

But I don't know DCCP code at all so I might be totally off and I
haven't tested this at all...  It was just easier to write a patch than
to try to explain in words.  Maybe we should clone the ccid instead of
setting it to NULL.  Or I might be completely wrong.

---
 net/dccp/minisocks.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
index 25187528c308..4cbfcccbbbbb 100644
--- a/net/dccp/minisocks.c
+++ b/net/dccp/minisocks.c
@@ -98,6 +98,8 @@ struct sock *dccp_create_openreq_child(const struct sock *sk,
 		newdp->dccps_timestamp_echo = dreq->dreq_timestamp_echo;
 		newdp->dccps_timestamp_time = dreq->dreq_timestamp_time;
 		newicsk->icsk_rto	    = DCCP_TIMEOUT_INIT;
+		newdp->dccps_hc_rx_ccid     = NULL;
+		newdp->dccps_hc_tx_ccid     = NULL;
 
 		INIT_LIST_HEAD(&newdp->dccps_featneg);
 		/*
-- 
2.11.0




_______________________________________________
Alsa-devel mailing list
Alsa-devel@alsa-project.org
https://mailman.alsa-project.org/mailman/listinfo/alsa-devel

^ permalink raw reply related	[flat|nested] 13+ messages in thread
* Re: KASAN: use-after-free Read in ccid_hc_tx_delete
@ 2019-11-21 20:14     ` Dan Carpenter
  0 siblings, 0 replies; 13+ messages in thread
From: Dan Carpenter @ 2019-11-21 20:14 UTC (permalink / raw)
  To: dccp

On Thu, Nov 21, 2019 at 07:00:00AM -0800, syzbot wrote:
> syzbot has bisected this bug to:
> 
> commit f04684b4d85d6371126f476d3268ebf6a0bd57cf
> Author: Dan Carpenter <dan.carpenter@oracle.com>
> Date:   Thu Jun 21 08:07:21 2018 +0000
> 
>     ALSA: lx6464es: Missing error code in snd_lx6464es_create()
> 
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x\x10dd11cae00000
> start commit:   eb6cf9f8 Merge tag 'arm64-fixes' of git://git.kernel.org/p..
> git tree:       upstream
> final crash:    https://syzkaller.appspot.com/x/report.txt?x\x12dd11cae00000
> console output: https://syzkaller.appspot.com/x/log.txt?x\x14dd11cae00000
> kernel config:  https://syzkaller.appspot.com/x/.config?xÈ970c89a0efbb23
> dashboard link: https://syzkaller.appspot.com/bug?extid967c1caf256f4d5aefe
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x\x11022ccd400000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x\x124581db400000
> 
> Reported-by: syzbot+3967c1caf256f4d5aefe@syzkaller.appspotmail.com
> Fixes: f04684b4d85d ("ALSA: lx6464es: Missing error code in
> snd_lx6464es_create()")
> 
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection

This crash isn't related to my commit, it's seems something specific to
DCCP.

My guess is that the fix is probably something like this.  The old sk
and the new sk re-use the same newdp->dccps_hc_rx/tx_ccid pointers.
The first sk destructor frees it and that causes a use after free when
the second destructor tries to free it.

But I don't know DCCP code at all so I might be totally off and I
haven't tested this at all...  It was just easier to write a patch than
to try to explain in words.  Maybe we should clone the ccid instead of
setting it to NULL.  Or I might be completely wrong.

---
 net/dccp/minisocks.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
index 25187528c308..4cbfcccbbbbb 100644
--- a/net/dccp/minisocks.c
+++ b/net/dccp/minisocks.c
@@ -98,6 +98,8 @@ struct sock *dccp_create_openreq_child(const struct sock *sk,
 		newdp->dccps_timestamp_echo = dreq->dreq_timestamp_echo;
 		newdp->dccps_timestamp_time = dreq->dreq_timestamp_time;
 		newicsk->icsk_rto	    = DCCP_TIMEOUT_INIT;
+		newdp->dccps_hc_rx_ccid     = NULL;
+		newdp->dccps_hc_tx_ccid     = NULL;
 
 		INIT_LIST_HEAD(&newdp->dccps_featneg);
 		/*
-- 
2.11.0




^ permalink raw reply related	[flat|nested] 13+ messages in thread
* Re: KASAN: use-after-free Read in ccid_hc_tx_delete
  2019-11-21 20:14     ` [alsa-devel] " Dan Carpenter
  (?)
@ 2020-01-21 15:39       ` Dan Carpenter
  -1 siblings, 0 replies; 13+ messages in thread
From: Dan Carpenter @ 2020-01-21 15:39 UTC (permalink / raw)
  To: syzbot
  Cc: alsa-devel, davem, dccp, gerrit, linux-kernel, netdev, perex,
	syzkaller-bugs, tiwai, tiwai, Eric Dumazet

On Thu, Nov 21, 2019 at 11:14:33PM +0300, Dan Carpenter wrote:
> On Thu, Nov 21, 2019 at 07:00:00AM -0800, syzbot wrote:
> > syzbot has bisected this bug to:
> > 
> > commit f04684b4d85d6371126f476d3268ebf6a0bd57cf
> > Author: Dan Carpenter <dan.carpenter@oracle.com>
> > Date:   Thu Jun 21 08:07:21 2018 +0000
> > 
> >     ALSA: lx6464es: Missing error code in snd_lx6464es_create()
> > 
> > bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=10dd11cae00000
> > start commit:   eb6cf9f8 Merge tag 'arm64-fixes' of git://git.kernel.org/p..
> > git tree:       upstream
> > final crash:    https://syzkaller.appspot.com/x/report.txt?x=12dd11cae00000
> > console output: https://syzkaller.appspot.com/x/log.txt?x=14dd11cae00000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=c8970c89a0efbb23
> > dashboard link: https://syzkaller.appspot.com/bug?extid=3967c1caf256f4d5aefe
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11022ccd400000
> > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=124581db400000
> > 
> > Reported-by: syzbot+3967c1caf256f4d5aefe@syzkaller.appspotmail.com
> > Fixes: f04684b4d85d ("ALSA: lx6464es: Missing error code in
> > snd_lx6464es_create()")
> > 
> > For information about bisection process see: https://goo.gl/tpsmEJ#bisection
> 
> This crash isn't related to my commit, it's seems something specific to
> DCCP.
> 
> My guess is that the fix is probably something like this.  The old sk
> and the new sk re-use the same newdp->dccps_hc_rx/tx_ccid pointers.
> The first sk destructor frees it and that causes a use after free when
> the second destructor tries to free it.
> 
> But I don't know DCCP code at all so I might be totally off and I
> haven't tested this at all...  It was just easier to write a patch than
> to try to explain in words.  Maybe we should clone the ccid instead of
> setting it to NULL.  Or I might be completely wrong.
> 
> ---
>  net/dccp/minisocks.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
> index 25187528c308..4cbfcccbbbbb 100644
> --- a/net/dccp/minisocks.c
> +++ b/net/dccp/minisocks.c
> @@ -98,6 +98,8 @@ struct sock *dccp_create_openreq_child(const struct sock *sk,
>  		newdp->dccps_timestamp_echo = dreq->dreq_timestamp_echo;
>  		newdp->dccps_timestamp_time = dreq->dreq_timestamp_time;
>  		newicsk->icsk_rto	    = DCCP_TIMEOUT_INIT;
> +		newdp->dccps_hc_rx_ccid     = NULL;
> +		newdp->dccps_hc_tx_ccid     = NULL;
>  
>  		INIT_LIST_HEAD(&newdp->dccps_featneg);
>  		/*

Could someone take a look at this?  It seem like a pretty serious bug
but DCCP is not very actively maintained and a lot of distributions
disable it.

regards,
dan carpenter

^ permalink raw reply	[flat|nested] 13+ messages in thread
* Re: [alsa-devel] KASAN: use-after-free Read in ccid_hc_tx_delete
@ 2020-01-21 15:39       ` Dan Carpenter
  0 siblings, 0 replies; 13+ messages in thread
From: Dan Carpenter @ 2020-01-21 15:39 UTC (permalink / raw)
  To: syzbot
  Cc: gerrit, alsa-devel, dccp, tiwai, netdev, tiwai, syzkaller-bugs,
	linux-kernel, Eric Dumazet, davem

On Thu, Nov 21, 2019 at 11:14:33PM +0300, Dan Carpenter wrote:
> On Thu, Nov 21, 2019 at 07:00:00AM -0800, syzbot wrote:
> > syzbot has bisected this bug to:
> > 
> > commit f04684b4d85d6371126f476d3268ebf6a0bd57cf
> > Author: Dan Carpenter <dan.carpenter@oracle.com>
> > Date:   Thu Jun 21 08:07:21 2018 +0000
> > 
> >     ALSA: lx6464es: Missing error code in snd_lx6464es_create()
> > 
> > bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=10dd11cae00000
> > start commit:   eb6cf9f8 Merge tag 'arm64-fixes' of git://git.kernel.org/p..
> > git tree:       upstream
> > final crash:    https://syzkaller.appspot.com/x/report.txt?x=12dd11cae00000
> > console output: https://syzkaller.appspot.com/x/log.txt?x=14dd11cae00000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=c8970c89a0efbb23
> > dashboard link: https://syzkaller.appspot.com/bug?extid=3967c1caf256f4d5aefe
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11022ccd400000
> > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=124581db400000
> > 
> > Reported-by: syzbot+3967c1caf256f4d5aefe@syzkaller.appspotmail.com
> > Fixes: f04684b4d85d ("ALSA: lx6464es: Missing error code in
> > snd_lx6464es_create()")
> > 
> > For information about bisection process see: https://goo.gl/tpsmEJ#bisection
> 
> This crash isn't related to my commit, it's seems something specific to
> DCCP.
> 
> My guess is that the fix is probably something like this.  The old sk
> and the new sk re-use the same newdp->dccps_hc_rx/tx_ccid pointers.
> The first sk destructor frees it and that causes a use after free when
> the second destructor tries to free it.
> 
> But I don't know DCCP code at all so I might be totally off and I
> haven't tested this at all...  It was just easier to write a patch than
> to try to explain in words.  Maybe we should clone the ccid instead of
> setting it to NULL.  Or I might be completely wrong.
> 
> ---
>  net/dccp/minisocks.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
> index 25187528c308..4cbfcccbbbbb 100644
> --- a/net/dccp/minisocks.c
> +++ b/net/dccp/minisocks.c
> @@ -98,6 +98,8 @@ struct sock *dccp_create_openreq_child(const struct sock *sk,
>  		newdp->dccps_timestamp_echo = dreq->dreq_timestamp_echo;
>  		newdp->dccps_timestamp_time = dreq->dreq_timestamp_time;
>  		newicsk->icsk_rto	    = DCCP_TIMEOUT_INIT;
> +		newdp->dccps_hc_rx_ccid     = NULL;
> +		newdp->dccps_hc_tx_ccid     = NULL;
>  
>  		INIT_LIST_HEAD(&newdp->dccps_featneg);
>  		/*

Could someone take a look at this?  It seem like a pretty serious bug
but DCCP is not very actively maintained and a lot of distributions
disable it.

regards,
dan carpenter
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^ permalink raw reply	[flat|nested] 13+ messages in thread
* Re: KASAN: use-after-free Read in ccid_hc_tx_delete
@ 2020-01-21 15:39       ` Dan Carpenter
  0 siblings, 0 replies; 13+ messages in thread
From: Dan Carpenter @ 2020-01-21 15:39 UTC (permalink / raw)
  To: dccp

On Thu, Nov 21, 2019 at 11:14:33PM +0300, Dan Carpenter wrote:
> On Thu, Nov 21, 2019 at 07:00:00AM -0800, syzbot wrote:
> > syzbot has bisected this bug to:
> > 
> > commit f04684b4d85d6371126f476d3268ebf6a0bd57cf
> > Author: Dan Carpenter <dan.carpenter@oracle.com>
> > Date:   Thu Jun 21 08:07:21 2018 +0000
> > 
> >     ALSA: lx6464es: Missing error code in snd_lx6464es_create()
> > 
> > bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x\x10dd11cae00000
> > start commit:   eb6cf9f8 Merge tag 'arm64-fixes' of git://git.kernel.org/p..
> > git tree:       upstream
> > final crash:    https://syzkaller.appspot.com/x/report.txt?x\x12dd11cae00000
> > console output: https://syzkaller.appspot.com/x/log.txt?x\x14dd11cae00000
> > kernel config:  https://syzkaller.appspot.com/x/.config?xÈ970c89a0efbb23
> > dashboard link: https://syzkaller.appspot.com/bug?extid967c1caf256f4d5aefe
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x\x11022ccd400000
> > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x\x124581db400000
> > 
> > Reported-by: syzbot+3967c1caf256f4d5aefe@syzkaller.appspotmail.com
> > Fixes: f04684b4d85d ("ALSA: lx6464es: Missing error code in
> > snd_lx6464es_create()")
> > 
> > For information about bisection process see: https://goo.gl/tpsmEJ#bisection
> 
> This crash isn't related to my commit, it's seems something specific to
> DCCP.
> 
> My guess is that the fix is probably something like this.  The old sk
> and the new sk re-use the same newdp->dccps_hc_rx/tx_ccid pointers.
> The first sk destructor frees it and that causes a use after free when
> the second destructor tries to free it.
> 
> But I don't know DCCP code at all so I might be totally off and I
> haven't tested this at all...  It was just easier to write a patch than
> to try to explain in words.  Maybe we should clone the ccid instead of
> setting it to NULL.  Or I might be completely wrong.
> 
> ---
>  net/dccp/minisocks.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
> index 25187528c308..4cbfcccbbbbb 100644
> --- a/net/dccp/minisocks.c
> +++ b/net/dccp/minisocks.c
> @@ -98,6 +98,8 @@ struct sock *dccp_create_openreq_child(const struct sock *sk,
>  		newdp->dccps_timestamp_echo = dreq->dreq_timestamp_echo;
>  		newdp->dccps_timestamp_time = dreq->dreq_timestamp_time;
>  		newicsk->icsk_rto	    = DCCP_TIMEOUT_INIT;
> +		newdp->dccps_hc_rx_ccid     = NULL;
> +		newdp->dccps_hc_tx_ccid     = NULL;
>  
>  		INIT_LIST_HEAD(&newdp->dccps_featneg);
>  		/*

Could someone take a look at this?  It seem like a pretty serious bug
but DCCP is not very actively maintained and a lot of distributions
disable it.

regards,
dan carpenter

^ permalink raw reply	[flat|nested] 13+ messages in thread
end of thread, other threads:[~2020-01-21 15:40 UTC | newest]

Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-08-27 17:10 KASAN: use-after-free Read in ccid_hc_tx_delete syzbot
2018-08-27 17:10 ` syzbot
2018-12-14 21:58 ` syzbot
2018-12-14 21:58   ` syzbot
2019-11-21 15:00 ` syzbot
2019-11-21 15:00   ` syzbot
2019-11-21 15:00   ` [alsa-devel] " syzbot
2019-11-21 20:14   ` Dan Carpenter
2019-11-21 20:14     ` Dan Carpenter
2019-11-21 20:14     ` [alsa-devel] " Dan Carpenter
2020-01-21 15:39     ` Dan Carpenter
2020-01-21 15:39       ` Dan Carpenter
2020-01-21 15:39       ` [alsa-devel] " Dan Carpenter

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