[syzbot] [bluetooth?] BUG: sleeping function called from invalid context in hci_le_create_big_complete_evt

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 480e035fc4c7 Merge tag 'drm-next-2024-03-13' of https://gi..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=12154da9180000
kernel config: https://syzkaller.appspot.com/x/.config?x=1e5b814e91787669
dashboard link: https://syzkaller.appspot.com/bug?extid=2fb0835e0c9cefc34614
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=14136223180000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11ee2e75180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/5f73b6ef963d/disk-480e035f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/46c949396aad/vmlinux-480e035f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e3b4d0f5a5f8/bzImage-480e035f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2fb083...@syzkaller.appspotmail.com

BUG: sleeping function called from invalid context at kernel/locking/mutex.c:585
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 5070, name: kworker/u9:2
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
4 locks held by kworker/u9:2/5070:
#0: ffff888015be3948 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline]
#0: ffff888015be3948 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x1770 kernel/workqueue.c:3335
#1: ffffc90003b6fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline]
#1: ffffc90003b6fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x1770 kernel/workqueue.c:3335
#2: ffff8880665d0078 (&hdev->lock){+.+.}-{3:3}, at: hci_le_create_big_complete_evt+0xcf/0xae0 net/bluetooth/hci_event.c:6914
#3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
#3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
#3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: hci_le_create_big_complete_evt+0xdb/0xae0 net/bluetooth/hci_event.c:6915
CPU: 0 PID: 5070 Comm: kworker/u9:2 Not tainted 6.8.0-syzkaller-08073-g480e035fc4c7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: hci0 hci_rx_work
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
__might_resched+0x5d4/0x780 kernel/sched/core.c:10187
__mutex_lock_common kernel/locking/mutex.c:585 [inline]
__mutex_lock+0xc1/0xd70 kernel/locking/mutex.c:752
hci_connect_cfm include/net/bluetooth/hci_core.h:2004 [inline]
hci_le_create_big_complete_evt+0x3d9/0xae0 net/bluetooth/hci_event.c:6939
hci_event_func net/bluetooth/hci_event.c:7514 [inline]
hci_event_packet+0xa53/0x1540 net/bluetooth/hci_event.c:7569
hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4171
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
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:243
</TASK>

=============================
[ BUG: Invalid wait context ]
6.8.0-syzkaller-08073-g480e035fc4c7 #0 Tainted: G W
-----------------------------
kworker/u9:2/5070 is trying to lock:
ffffffff8f4f5aa8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2004 [inline]
ffffffff8f4f5aa8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_le_create_big_complete_evt+0x3d9/0xae0 net/bluetooth/hci_event.c:6939
other info that might help us debug this:
context-{4:4}
4 locks held by kworker/u9:2/5070:
#0: ffff888015be3948 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline]
#0: ffff888015be3948 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x1770 kernel/workqueue.c:3335
#1: ffffc90003b6fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline]
#1: ffffc90003b6fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x1770 kernel/workqueue.c:3335
#2: ffff8880665d0078 (&hdev->lock){+.+.}-{3:3}, at: hci_le_create_big_complete_evt+0xcf/0xae0 net/bluetooth/hci_event.c:6914
#3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
#3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
#3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: hci_le_create_big_complete_evt+0xdb/0xae0 net/bluetooth/hci_event.c:6915
stack backtrace:
CPU: 0 PID: 5070 Comm: kworker/u9:2 Tainted: G W 6.8.0-syzkaller-08073-g480e035fc4c7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: hci0 hci_rx_work
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
print_lock_invalid_wait_context kernel/locking/lockdep.c:4751 [inline]
check_wait_context kernel/locking/lockdep.c:4821 [inline]
__lock_acquire+0x1507/0x1fd0 kernel/locking/lockdep.c:5087
lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
hci_connect_cfm include/net/bluetooth/hci_core.h:2004 [inline]
hci_le_create_big_complete_evt+0x3d9/0xae0 net/bluetooth/hci_event.c:6939
hci_event_func net/bluetooth/hci_event.c:7514 [inline]
hci_event_packet+0xa53/0x1540 net/bluetooth/hci_event.c:7569
hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4171
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
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:243
</TASK>
==================================================================
BUG: KASAN: slab-use-after-free in hci_le_create_big_complete_evt+0x383/0xae0
Read of size 8 at addr ffff88807cb1c000 by task kworker/u9:2/5070

CPU: 0 PID: 5070 Comm: kworker/u9:2 Tainted: G W 6.8.0-syzkaller-08073-g480e035fc4c7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: hci0 hci_rx_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_le_create_big_complete_evt+0x383/0xae0
hci_event_func net/bluetooth/hci_event.c:7514 [inline]
hci_event_packet+0xa53/0x1540 net/bluetooth/hci_event.c:7569
hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4171
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
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:243
</TASK>

Allocated by task 5070:
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+0x1db/0x360 mm/slub.c:3997
kmalloc include/linux/slab.h:628 [inline]
kzalloc include/linux/slab.h:749 [inline]
hci_conn_add+0xc7/0x13a0 net/bluetooth/hci_conn.c:914
hci_le_big_sync_established_evt+0x1cf/0xb90 net/bluetooth/hci_event.c:6980
hci_event_func net/bluetooth/hci_event.c:7514 [inline]
hci_event_packet+0xa53/0x1540 net/bluetooth/hci_event.c:7569
hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4171
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
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:243

Freed by task 5070:
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:579
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:2106 [inline]
slab_free mm/slub.c:4280 [inline]
kfree+0x14a/0x380 mm/slub.c:4390
device_release+0x99/0x1c0
kobject_cleanup lib/kobject.c:689 [inline]
kobject_release lib/kobject.c:720 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x22f/0x480 lib/kobject.c:737
hci_conn_cleanup net/bluetooth/hci_conn.c:176 [inline]
hci_conn_del+0x900/0xc80 net/bluetooth/hci_conn.c:1126
hci_le_create_big_complete_evt+0x619/0xae0 net/bluetooth/hci_event.c:6941
hci_event_func net/bluetooth/hci_event.c:7514 [inline]
hci_event_packet+0xa53/0x1540 net/bluetooth/hci_event.c:7569
hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4171
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
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:243

The buggy address belongs to the object at ffff88807cb1c000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 0 bytes inside of
freed 8192-byte region [ffff88807cb1c000, ffff88807cb1e000)

The buggy address belongs to the physical page:
page:ffffea0001f2c600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7cb18
head:ffffea0001f2c600 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
ksm flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888014c42280 ffffea0001f2cc00 dead000000000003
raw: 0000000000000000 0000000080020002 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 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4524, tgid 4524 (S10udev), ts 19996984719, free_ts 17455903844
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1533
prep_new_page mm/page_alloc.c:1540 [inline]
get_page_from_freelist+0x33ea/0x3580 mm/page_alloc.c:3311
__alloc_pages+0x256/0x680 mm/page_alloc.c:4569
__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:2175
allocate_slab mm/slub.c:2338 [inline]
new_slab+0x84/0x2f0 mm/slub.c:2391
___slab_alloc+0xc73/0x1260 mm/slub.c:3525
__slab_alloc mm/slub.c:3610 [inline]
__slab_alloc_node mm/slub.c:3663 [inline]
slab_alloc_node mm/slub.c:3835 [inline]
kmalloc_trace+0x269/0x360 mm/slub.c:3992
kmalloc include/linux/slab.h:628 [inline]
kzalloc include/linux/slab.h:749 [inline]
tomoyo_print_bprm security/tomoyo/audit.c:26 [inline]
tomoyo_init_log+0x11ce/0x2050 security/tomoyo/audit.c:264
tomoyo_supervisor+0x38a/0x11f0 security/tomoyo/common.c:2089
tomoyo_audit_env_log security/tomoyo/environ.c:36 [inline]
tomoyo_env_perm+0x178/0x210 security/tomoyo/environ.c:63
tomoyo_environ security/tomoyo/domain.c:672 [inline]
tomoyo_find_next_domain+0x1384/0x1cf0 security/tomoyo/domain.c:878
tomoyo_bprm_check_security+0x115/0x180 security/tomoyo/tomoyo.c:102
security_bprm_check+0x65/0x90 security/security.c:1185
search_binary_handler fs/exec.c:1765 [inline]
exec_binprm fs/exec.c:1819 [inline]
bprm_execve+0xa56/0x1790 fs/exec.c:1871
do_execveat_common+0x553/0x700 fs/exec.c:1978
do_execve fs/exec.c:2052 [inline]
__do_sys_execve fs/exec.c:2128 [inline]
__se_sys_execve fs/exec.c:2123 [inline]
__x64_sys_execve+0x92/0xb0 fs/exec.c:2123
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:2346
free_unref_page+0x37/0x3f0 mm/page_alloc.c:2486
free_contig_range+0x9e/0x160 mm/page_alloc.c:6547
destroy_args+0x8a/0x890 mm/debug_vm_pgtable.c:1036
debug_vm_pgtable+0x4be/0x550 mm/debug_vm_pgtable.c:1416
do_one_initcall+0x238/0x830 init/main.c:1241
do_initcall_level+0x157/0x210 init/main.c:1303
do_initcalls+0x3f/0x80 init/main.c:1319
kernel_init_freeable+0x435/0x5d0 init/main.c:1550
kernel_init+0x1d/0x2a0 init/main.c:1439
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243

Memory state around the buggy address:
ffff88807cb1bf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88807cb1bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88807cb1c000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88807cb1c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88807cb1c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
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If the report is already addressed, let syzbot know by replying with:
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If you want syzbot to run the reproducer, reply with:
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If you attach or paste a git patch, syzbot will apply it before testing.

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If you want to undo deduplication, reply with:
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[Hillf Danton]

On Sun, 07 Apr 2024 04:33:29 -0700

> syzbot found the following issue on:
>
> HEAD commit: 480e035fc4c7 Merge tag 'drm-next-2024-03-13' of https://gi..
> git tree: upstream

> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11ee2e75180000

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 480e035fc4c7

--- x/net/bluetooth/hci_event.c
+++ y/net/bluetooth/hci_event.c
@@ -6936,8 +6936,8 @@ static void hci_le_create_big_complete_e
continue;
}

- hci_connect_cfm(conn, ev->status);
rcu_read_unlock();
+ hci_connect_cfm(conn, ev->status);
hci_conn_del(conn);
rcu_read_lock();
}
--

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Read in hci_le_create_big_complete_evt

==================================================================
BUG: KASAN: slab-use-after-free in hci_le_create_big_complete_evt+0x383/0xb00
Read of size 8 at addr ffff88801f0b4000 by task kworker/u9:1/4465

CPU: 1 PID: 4465 Comm: kworker/u9:1 Not tainted 6.8.0-syzkaller-08073-g480e035fc4c7-dirty #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: hci0 hci_rx_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_le_create_big_complete_evt+0x383/0xb00

hci_event_func net/bluetooth/hci_event.c:7514 [inline]
hci_event_packet+0xa53/0x1540 net/bluetooth/hci_event.c:7569
hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4171
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
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:243
</TASK>

Allocated by task 4465:

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+0x1db/0x360 mm/slub.c:3997
kmalloc include/linux/slab.h:628 [inline]
kzalloc include/linux/slab.h:749 [inline]
hci_conn_add+0xc7/0x13a0 net/bluetooth/hci_conn.c:914
hci_le_big_sync_established_evt+0x1cf/0xb90 net/bluetooth/hci_event.c:6980
hci_event_func net/bluetooth/hci_event.c:7514 [inline]
hci_event_packet+0xa53/0x1540 net/bluetooth/hci_event.c:7569
hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4171
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
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:243

Freed by task 4465:

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:579
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:2106 [inline]
slab_free mm/slub.c:4280 [inline]
kfree+0x14a/0x380 mm/slub.c:4390
device_release+0x99/0x1c0
kobject_cleanup lib/kobject.c:689 [inline]
kobject_release lib/kobject.c:720 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x22f/0x480 lib/kobject.c:737
hci_conn_cleanup net/bluetooth/hci_conn.c:176 [inline]
hci_conn_del+0x900/0xc80 net/bluetooth/hci_conn.c:1126

hci_le_create_big_complete_evt+0x61b/0xb00 net/bluetooth/hci_event.c:6941

hci_event_func net/bluetooth/hci_event.c:7514 [inline]
hci_event_packet+0xa53/0x1540 net/bluetooth/hci_event.c:7569
hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4171
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
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:243

The buggy address belongs to the object at ffff88801f0b4000

which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 0 bytes inside of

freed 8192-byte region [ffff88801f0b4000, ffff88801f0b6000)

The buggy address belongs to the physical page:

page:ffffea00007c2c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1f0b0
head:ffffea00007c2c00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0

flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()

raw: 00fff00000000840 ffff888014c42280 ffffea00007efc00 dead000000000002

raw: 0000000000000000 0000000080020002 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 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4736, tgid 4736 (dhcpcd), ts 33772916994, free_ts 33772629416

set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1533
prep_new_page mm/page_alloc.c:1540 [inline]
get_page_from_freelist+0x33ea/0x3580 mm/page_alloc.c:3311
__alloc_pages+0x256/0x680 mm/page_alloc.c:4569
__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:2175
allocate_slab mm/slub.c:2338 [inline]
new_slab+0x84/0x2f0 mm/slub.c:2391
___slab_alloc+0xc73/0x1260 mm/slub.c:3525
__slab_alloc mm/slub.c:3610 [inline]
__slab_alloc_node mm/slub.c:3663 [inline]
slab_alloc_node mm/slub.c:3835 [inline]

__do_kmalloc_node mm/slub.c:3965 [inline]
__kmalloc_node_track_caller+0x2d6/0x4e0 mm/slub.c:3986
kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:599
__alloc_skb+0x1f3/0x440 net/core/skbuff.c:668
alloc_skb include/linux/skbuff.h:1318 [inline]
netlink_dump+0x1e6/0xe50 net/netlink/af_netlink.c:2229
netlink_recvmsg+0x6bb/0x11d0 net/netlink/af_netlink.c:1987
sock_recvmsg_nosec net/socket.c:1046 [inline]
sock_recvmsg+0x22f/0x280 net/socket.c:1068
____sys_recvmsg+0x1db/0x470 net/socket.c:2803
___sys_recvmsg net/socket.c:2845 [inline]
__sys_recvmsg+0x2f0/0x3e0 net/socket.c:2875
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x6d/0x75
page last free pid 4736 tgid 4736 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:2346
free_unref_page+0x37/0x3f0 mm/page_alloc.c:2486

discard_slab mm/slub.c:2437 [inline]
__put_partials+0xeb/0x130 mm/slub.c:2906
put_cpu_partial+0x17c/0x250 mm/slub.c:2981
__slab_free+0x2ea/0x3d0 mm/slub.c:4151
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x5e/0xc0 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:322
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook mm/slub.c:3798 [inline]
slab_alloc_node mm/slub.c:3845 [inline]
kmem_cache_alloc_node+0x194/0x380 mm/slub.c:3888
kmalloc_reserve+0xa8/0x2a0 net/core/skbuff.c:577
__alloc_skb+0x1f3/0x440 net/core/skbuff.c:668
netlink_sendmsg+0x637/0xcb0 net/netlink/af_netlink.c:1880
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0x221/0x270 net/socket.c:745
__sys_sendto+0x3a4/0x4f0 net/socket.c:2191
__do_sys_sendto net/socket.c:2203 [inline]
__se_sys_sendto net/socket.c:2199 [inline]
__x64_sys_sendto+0xde/0x100 net/socket.c:2199
do_syscall_64+0xfb/0x240

Memory state around the buggy address:

ffff88801f0b3f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88801f0b3f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88801f0b4000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88801f0b4080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88801f0b4100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit: 480e035f Merge tag 'drm-next-2024-03-13' of https://gi..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=16896499180000

kernel config: https://syzkaller.appspot.com/x/.config?x=1e5b814e91787669
dashboard link: https://syzkaller.appspot.com/bug?extid=2fb0835e0c9cefc34614
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=17b92e05180000

[syzbot]

syzbot has bisected this issue to:

commit a0bfde167b506423111ddb8cd71930497a40fc54
Author: Iulia Tanasescu <iulia.t...@nxp.com>
Date: Tue May 30 14:21:59 2023 +0000

Bluetooth: ISO: Add support for connecting multiple BISes

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=146c679d180000
start commit: 8568bb2ccc27 Add linux-next specific files for 20240405
git tree: linux-next
final oops: https://syzkaller.appspot.com/x/report.txt?x=166c679d180000
console output: https://syzkaller.appspot.com/x/log.txt?x=126c679d180000
kernel config: https://syzkaller.appspot.com/x/.config?x=48ca5acf8d2eb3bc
dashboard link: https://syzkaller.appspot.com/bug?extid=2fb0835e0c9cefc34614
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1338efc5180000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15428f4b180000

Reported-by: syzbot+2fb083...@syzkaller.appspotmail.com
Fixes: a0bfde167b50 ("Bluetooth: ISO: Add support for connecting multiple BISes")

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

[Hillf Danton]

On Sun, 07 Apr 2024 04:33:29 -0700

> syzbot found the following issue on:
>
> HEAD commit: 480e035fc4c7 Merge tag 'drm-next-2024-03-13' of https://gi..
> git tree: upstream

> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11ee2e75180000

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 480e035fc4c7

--- x/net/bluetooth/hci_event.c
+++ y/net/bluetooth/hci_event.c

@@ -6902,7 +6902,7 @@ static void hci_le_create_big_complete_e
struct sk_buff *skb)
{
struct hci_evt_le_create_big_complete *ev = data;
- struct hci_conn *conn;
+ struct hci_conn *conn, *next;
__u8 i = 0;

BT_DBG("%s status 0x%2.2x", hdev->name, ev->status);
@@ -6912,38 +6912,29 @@ static void hci_le_create_big_complete_e
return;

hci_dev_lock(hdev);
- rcu_read_lock();
-
/* Connect all BISes that are bound to the BIG */
- list_for_each_entry_rcu(conn, &hdev->conn_hash.list, list) {
+ list_for_each_entry_safe(conn, next, &hdev->conn_hash.list, list) {
if (bacmp(&conn->dst, BDADDR_ANY) ||
conn->type != ISO_LINK ||
conn->iso_qos.bcast.big != ev->handle)
continue;

- if (hci_conn_set_handle(conn,
- __le16_to_cpu(ev->bis_handle[i++])))
+ if (hci_conn_set_handle(conn, __le16_to_cpu(ev->bis_handle[i++])))
continue;

if (!ev->status) {
conn->state = BT_CONNECTED;
set_bit(HCI_CONN_BIG_CREATED, &conn->flags);
- rcu_read_unlock();
hci_debugfs_create_conn(conn);
hci_conn_add_sysfs(conn);
hci_iso_setup_path(conn);
- rcu_read_lock();
continue;
}

hci_connect_cfm(conn, ev->status);
- rcu_read_unlock();
hci_conn_del(conn);
- rcu_read_lock();
}

- rcu_read_unlock();
-
if (!ev->status && !i)
/* If no BISes have been connected for the BIG,
* terminate. This is in case all bound connections
@@ -6952,7 +6943,6 @@ static void hci_le_create_big_complete_e
*/
hci_cmd_sync_queue(hdev, hci_iso_term_big_sync,
UINT_PTR(ev->handle), NULL);
-
hci_dev_unlock(hdev);
}

--

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+2fb083...@syzkaller.appspotmail.com

Tested on:

commit: 480e035f Merge tag 'drm-next-2024-03-13' of https://gi..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

console output: https://syzkaller.appspot.com/x/log.txt?x=171f2b39180000

kernel config: https://syzkaller.appspot.com/x/.config?x=1e5b814e91787669
dashboard link: https://syzkaller.appspot.com/bug?extid=2fb0835e0c9cefc34614
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=14dfa699180000

Note: testing is done by a robot and is best-effort only.