Message-ID: <000000000000b7b62e0610db6b8a@google.com>
Date: Thu, 08 Feb 2024 01:27:31 -0800
From: syzbot <syzbot+3f0a39be7a2035700868@...kaller.appspotmail.com>
To: johan.hedberg@...il.com, linux-bluetooth@...r.kernel.org, 
	linux-kernel@...r.kernel.org, luiz.dentz@...il.com, marcel@...tmann.org, 
	syzkaller-bugs@...glegroups.com
Subject: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in __hci_acl_create_connection_sync

Hello,

syzbot found the following issue on:

HEAD commit:    b1d3a0e70c38 Add linux-next specific files for 20240208
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=15530be4180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=bb693ba195662a06
dashboard link: https://syzkaller.appspot.com/bug?extid=3f0a39be7a2035700868
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11d95147e80000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=107c2d8fe80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/176a6b395bbe/disk-b1d3a0e7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/02d7d46f81bd/vmlinux-b1d3a0e7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/18a5a5030e19/bzImage-b1d3a0e7.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3f0a39be7a2035700868@...kaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in __hci_acl_create_connection_sync+0x6ce/0x990 net/bluetooth/hci_sync.c:6518
Write of size 2 at addr ffff88806b80c036 by task kworker/u9:4/5087

CPU: 0 PID: 5087 Comm: kworker/u9:4 Not tainted 6.8.0-rc3-next-20240208-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Workqueue: hci4 hci_cmd_sync_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 __hci_acl_create_connection_sync+0x6ce/0x990 net/bluetooth/hci_sync.c:6518
 hci_cmd_sync_work+0x22b/0x400 net/bluetooth/hci_sync.c:306
 process_one_work kernel/workqueue.c:3102 [inline]
 process_scheduled_works+0x9d7/0x1730 kernel/workqueue.c:3182
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3263
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:242
 </TASK>

Allocated by task 6357:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 kmalloc_trace+0x1d9/0x360 mm/slub.c:4013
 kmalloc include/linux/slab.h:590 [inline]
 kzalloc include/linux/slab.h:711 [inline]
 hci_conn_add+0xc7/0x13a0 net/bluetooth/hci_conn.c:914
 hci_conn_add_unset net/bluetooth/hci_conn.c:1016 [inline]
 hci_connect_acl+0x15d/0x470 net/bluetooth/hci_conn.c:1632
 hci_connect_sco+0x3f/0x350 net/bluetooth/hci_conn.c:1692
 sco_connect net/bluetooth/sco.c:266 [inline]
 sco_sock_connect+0x2ce/0x950 net/bluetooth/sco.c:591
 __sys_connect_file net/socket.c:2048 [inline]
 __sys_connect+0x2df/0x310 net/socket.c:2065
 __do_sys_connect net/socket.c:2075 [inline]
 __se_sys_connect net/socket.c:2072 [inline]
 __x64_sys_connect+0x7a/0x90 net/socket.c:2072
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

Freed by task 5087:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:586
 poison_slab_object+0xa6/0xe0 mm/kasan/common.c:240
 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2122 [inline]
 slab_free mm/slub.c:4296 [inline]
 kfree+0x14a/0x380 mm/slub.c:4406
 device_release+0x99/0x1c0
 kobject_cleanup lib/kobject.c:682 [inline]
 kobject_release lib/kobject.c:716 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1f5/0x430 lib/kobject.c:733
 hci_conn_cleanup net/bluetooth/hci_conn.c:176 [inline]
 hci_conn_del+0x8f0/0xc70 net/bluetooth/hci_conn.c:1126
 hci_abort_conn_sync+0x583/0xde0 net/bluetooth/hci_sync.c:5361
 __hci_acl_create_connection_sync+0x60c/0x990 net/bluetooth/hci_sync.c:6554
 hci_cmd_sync_work+0x22b/0x400 net/bluetooth/hci_sync.c:306
 process_one_work kernel/workqueue.c:3102 [inline]
 process_scheduled_works+0x9d7/0x1730 kernel/workqueue.c:3182
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3263
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:242

The buggy address belongs to the object at ffff88806b80c000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 54 bytes inside of
 freed 4096-byte region [ffff88806b80c000, ffff88806b80d000)

The buggy address belongs to the physical page:
page:ffffea0001ae0200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6b808
head:ffffea0001ae0200 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff80000000840(slab|head|node=0|zone=1|lastcpupid=0xfff)
page_type: 0xffffffff()
raw: 00fff80000000840 ffff888014c42140 ffffea000073c600 dead000000000002
raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5397, tgid 5397 (syz-executor270), ts 117997642770, free_ts 25758092955
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1539
 prep_new_page mm/page_alloc.c:1546 [inline]
 get_page_from_freelist+0x34eb/0x3680 mm/page_alloc.c:3353
 __alloc_pages+0x256/0x6a0 mm/page_alloc.c:4609
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 alloc_slab_page+0x5f/0x160 mm/slub.c:2191
 allocate_slab mm/slub.c:2354 [inline]
 new_slab+0x84/0x2f0 mm/slub.c:2407
 ___slab_alloc+0xc73/0x1260 mm/slub.c:3541
 __slab_alloc mm/slub.c:3626 [inline]
 __slab_alloc_node mm/slub.c:3679 [inline]
 slab_alloc_node mm/slub.c:3851 [inline]
 __do_kmalloc_node mm/slub.c:3981 [inline]
 __kmalloc+0x2e3/0x4a0 mm/slub.c:3995
 kmalloc include/linux/slab.h:594 [inline]
 tomoyo_realpath_from_path+0xcf/0x5e0 security/tomoyo/realpath.c:251
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x2b7/0x740 security/tomoyo/file.c:822
 tomoyo_path_symlink+0xde/0x120 security/tomoyo/tomoyo.c:212
 security_path_symlink+0xe3/0x140 security/security.c:1870
 do_symlinkat+0x136/0x3a0 fs/namei.c:4502
 __do_sys_symlink fs/namei.c:4525 [inline]
 __se_sys_symlink fs/namei.c:4523 [inline]
 __x64_sys_symlink+0x7e/0x90 fs/namei.c:4523
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
page last free pid 1 tgid 1 stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1140 [inline]
 free_unref_page_prepare+0x968/0xa90 mm/page_alloc.c:2388
 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2528
 free_contig_range+0x9e/0x160 mm/page_alloc.c:6574
 destroy_args+0x8a/0x890 mm/debug_vm_pgtable.c:1028
 debug_vm_pgtable+0x4be/0x550 mm/debug_vm_pgtable.c:1408
 do_one_initcall+0x238/0x830 init/main.c:1233
 do_initcall_level+0x157/0x210 init/main.c:1295
 do_initcalls+0x3f/0x80 init/main.c:1311
 kernel_init_freeable+0x430/0x5d0 init/main.c:1542
 kernel_init+0x1d/0x2b0 init/main.c:1432
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:242

Memory state around the buggy address:
 ffff88806b80bf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88806b80bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88806b80c000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff88806b80c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88806b80c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
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