Hello,
syzbot found the following issue on:
HEAD commit: 13af6c74 Linux 4.19.136
git tree: linux-4.19.y
console output:
https://syzkaller.appspot.com/x/log.txt?x=17cc1114900000
kernel config:
https://syzkaller.appspot.com/x/.config?x=5b7578d3b5457a49
dashboard link:
https://syzkaller.appspot.com/bug?extid=2bb1968c6e2f8782c289
compiler: gcc (GCC) 10.1.0-syz 20200507
syz repro:
https://syzkaller.appspot.com/x/repro.syz?x=102c1114900000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by:
syzbot+2bb196...@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: use-after-free in hci_chan_del+0x13e/0x180 net/bluetooth/hci_conn.c:1666
Read of size 8 at addr ffff88808e7c5198 by task syz-executor.0/6469
CPU: 0 PID: 6469 Comm: syz-executor.0 Not tainted 4.19.136-syzkaller #0
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+0x1fc/0x2fe lib/dump_stack.c:118
print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
kasan_report_error.cold+0x8a/0x1c7 mm/kasan/report.c:354
kasan_report mm/kasan/report.c:412 [inline]
__asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433
hci_chan_del+0x13e/0x180 net/bluetooth/hci_conn.c:1666
l2cap_conn_del+0x44f/0x6b0 net/bluetooth/l2cap_core.c:1736
l2cap_disconn_cfm net/bluetooth/l2cap_core.c:7435 [inline]
l2cap_disconn_cfm+0x85/0xa0 net/bluetooth/l2cap_core.c:7428
hci_disconn_cfm include/net/bluetooth/hci_core.h:1261 [inline]
hci_conn_hash_flush+0x114/0x220 net/bluetooth/hci_conn.c:1495
hci_dev_do_close+0x624/0xe70 net/bluetooth/hci_core.c:1666
hci_unregister_dev+0x17c/0x7f0 net/bluetooth/hci_core.c:3271
vhci_release+0x70/0xe0 drivers/bluetooth/hci_vhci.c:354
__fput+0x2ce/0x890 fs/file_table.c:278
task_work_run+0x148/0x1c0 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0xbb2/0x2b70 kernel/exit.c:887
do_group_exit+0x125/0x310 kernel/exit.c:990
__do_sys_exit_group kernel/exit.c:1001 [inline]
__se_sys_exit_group kernel/exit.c:999 [inline]
__x64_sys_exit_group+0x3a/0x50 kernel/exit.c:999
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45cc79
Code: 00 00 00 84 00 48 05 98 16 00 00 48 89 44 24 10 48 89 04 24 48 c7 44 24 08 00 00 00 00 e8 2f 18 fc ff 64 48 8b 04 25 f8 ff ff <ff> 48 8b 40 30 48 8b 80 d0 00 00 00 48 89 04 24 e8 e2 02 fd ff 48
RSP: 002b:00007ffed10481e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000045cc79
RDX: 00000000004166d1 RSI: 0000000000ca85f0 RDI: 0000000000000043
RBP: 00000000004c2903 R08: 000000000000000b R09: 0000000000000000
R10: 0000000001b9f940 R11: 0000000000000246 R12: 0000000000000003
R13: 00007ffed1048330 R14: 00000000001622a8 R15: 00007ffed1048340
Allocated by task 18856:
kmem_cache_alloc_trace+0x12f/0x380 mm/slab.c:3625
kmalloc include/linux/slab.h:515 [inline]
sock_alloc_inode+0x5f/0x250 net/socket.c:247
alloc_inode+0x5d/0x180 fs/inode.c:211
new_inode_pseudo+0x14/0xe0 fs/inode.c:911
sock_alloc+0x3c/0x260 net/socket.c:547
__sock_create+0xba/0x740 net/socket.c:1240
sock_create net/socket.c:1316 [inline]
__sys_socket+0xef/0x200 net/socket.c:1346
__do_sys_socket net/socket.c:1355 [inline]
__se_sys_socket net/socket.c:1353 [inline]
__x64_sys_socket+0x6f/0xb0 net/socket.c:1353
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Freed by task 0:
__cache_free mm/slab.c:3503 [inline]
kfree+0xcc/0x210 mm/slab.c:3822
__rcu_reclaim kernel/rcu/rcu.h:231 [inline]
rcu_do_batch kernel/rcu/tree.c:2584 [inline]
invoke_rcu_callbacks kernel/rcu/tree.c:2897 [inline]
__rcu_process_callbacks kernel/rcu/tree.c:2864 [inline]
rcu_process_callbacks+0xa0d/0x18b0 kernel/rcu/tree.c:2881
__do_softirq+0x26c/0x9a0 kernel/softirq.c:292
The buggy address belongs to the object at ffff88808e7c5180
which belongs to the cache kmalloc-128 of size 128
The buggy address is located 24 bytes inside of
128-byte region [ffff88808e7c5180, ffff88808e7c5200)
The buggy address belongs to the page:
page:ffffea000239f140 count:1 mapcount:0 mapping:ffff88812c39c640 index:0x0
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffffea000237b448 ffffea0002335188 ffff88812c39c640
raw: 0000000000000000 ffff88808e7c5000 0000000100000015 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88808e7c5080: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
ffff88808e7c5100: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff88808e7c5180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88808e7c5200: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
ffff88808e7c5280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================
---
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