[moderation] [bluetooth?] KASAN: slab-use-after-free Read in hci_chan_sent

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 234cb065ad82 Add linux-next specific files for 20240605
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=17d51564980000
kernel config: https://syzkaller.appspot.com/x/.config?x=fc762e458631913
dashboard link: https://syzkaller.appspot.com/bug?extid=a07c29578afeddc4b885
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [johan....@gmail.com linux-b...@vger.kernel.org linux-...@vger.kernel.org luiz....@gmail.com mar...@holtmann.org]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f0492dc0386a/disk-234cb065.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/490224339088/vmlinux-234cb065.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5843c0673606/bzImage-234cb065.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a07c29...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in hci_chan_sent+0x67d/0xaf0 net/bluetooth/hci_core.c:3548
Read of size 8 at addr ffff88801e8a9018 by task kworker/u9:0/53

CPU: 1 PID: 53 Comm: kworker/u9:0 Tainted: G W 6.10.0-rc2-next-20240605-syzkaller #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Workqueue: hci1 hci_tx_work
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:91 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:117
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_chan_sent+0x67d/0xaf0 net/bluetooth/hci_core.c:3548
hci_sched_acl_pkt net/bluetooth/hci_core.c:3685 [inline]
hci_sched_acl net/bluetooth/hci_core.c:3725 [inline]
hci_tx_work+0x5c2/0x1590 net/bluetooth/hci_core.c:3818
process_one_work kernel/workqueue.c:3248 [inline]
process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3329
worker_thread+0x86d/0xd50 kernel/workqueue.c:3409
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>

Allocated by task 5127:
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_cache_noprof+0x19c/0x2c0 mm/slub.c:4153
kmalloc_noprof include/linux/slab.h:660 [inline]
kzalloc_noprof include/linux/slab.h:778 [inline]
hci_chan_create+0xc8/0x310 net/bluetooth/hci_conn.c:2724
l2cap_conn_add+0x69/0x8e0 net/bluetooth/l2cap_core.c:6860
l2cap_connect_cfm+0x136/0x1220 net/bluetooth/l2cap_core.c:7241
hci_connect_cfm include/net/bluetooth/hci_core.h:1971 [inline]
hci_remote_features_evt+0x536/0xaf0 net/bluetooth/hci_event.c:3721
hci_event_func net/bluetooth/hci_event.c:7424 [inline]
hci_event_packet+0xac0/0x1540 net/bluetooth/hci_event.c:7476
hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4087
process_one_work kernel/workqueue.c:3248 [inline]
process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3329
worker_thread+0x86d/0xd50 kernel/workqueue.c:3409
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 5122:
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+0xe0/0x150 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:2196 [inline]
slab_free mm/slub.c:4437 [inline]
kfree+0x149/0x360 mm/slub.c:4558
l2cap_conn_del+0x4eb/0x680 net/bluetooth/l2cap_core.c:1795
l2cap_connect_cfm+0x11f/0x1220 net/bluetooth/l2cap_core.c:7237
hci_connect_cfm include/net/bluetooth/hci_core.h:1971 [inline]
hci_conn_failed+0x1f6/0x340 net/bluetooth/hci_conn.c:1257
hci_abort_conn_sync+0x583/0xde0 net/bluetooth/hci_sync.c:5450
hci_cmd_sync_work+0x22b/0x400 net/bluetooth/hci_sync.c:310
process_one_work kernel/workqueue.c:3248 [inline]
process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3329
worker_thread+0x86d/0xd50 kernel/workqueue.c:3409
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

The buggy address belongs to the object at ffff88801e8a9000
which belongs to the cache kmalloc-128 of size 128
The buggy address is located 24 bytes inside of
freed 128-byte region [ffff88801e8a9000, ffff88801e8a9080)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1e8a9
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xfdffffff(slab)
raw: 00fff00000000000 ffff888015041a00 ffffea00006aa9c0 dead000000000004
raw: 0000000000000000 0000000000100010 00000001fdffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 4548, tgid 4548 (udevd), ts 39552199694, free_ts 39550682804
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1470
prep_new_page mm/page_alloc.c:1478 [inline]
get_page_from_freelist+0x2cbd/0x2d70 mm/page_alloc.c:3457
__alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4715
__alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
alloc_slab_page+0x5f/0x120 mm/slub.c:2265
allocate_slab+0x5a/0x2f0 mm/slub.c:2428
new_slab mm/slub.c:2481 [inline]
___slab_alloc+0xcd1/0x14b0 mm/slub.c:3667
__slab_alloc+0x58/0xa0 mm/slub.c:3757
__slab_alloc_node mm/slub.c:3810 [inline]
slab_alloc_node mm/slub.c:3989 [inline]
__kmalloc_cache_noprof+0x1d5/0x2c0 mm/slub.c:4148
kmalloc_noprof include/linux/slab.h:660 [inline]
kzalloc_noprof include/linux/slab.h:778 [inline]
kernfs_get_open_node fs/kernfs/file.c:525 [inline]
kernfs_fop_open+0x829/0xd10 fs/kernfs/file.c:700
do_dentry_open+0x95a/0x1720 fs/open.c:959
do_open fs/namei.c:3654 [inline]
path_openat+0x289f/0x3280 fs/namei.c:3811
do_filp_open+0x235/0x490 fs/namei.c:3838
do_sys_openat2+0x13e/0x1d0 fs/open.c:1409
do_sys_open fs/open.c:1424 [inline]
__do_sys_openat fs/open.c:1440 [inline]
__se_sys_openat fs/open.c:1435 [inline]
__x64_sys_openat+0x247/0x2a0 fs/open.c:1435
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 4545 tgid 4545 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1089 [inline]
free_unref_page+0xd22/0xea0 mm/page_alloc.c:2621
rcu_do_batch kernel/rcu/tree.c:2564 [inline]
rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2838
handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
__do_softirq kernel/softirq.c:588 [inline]
invoke_softirq kernel/softirq.c:428 [inline]
__irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637
irq_exit_rcu+0x9/0x30 kernel/softirq.c:649
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702

Memory state around the buggy address:
ffff88801e8a8f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88801e8a8f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88801e8a9000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88801e8a9080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88801e8a9100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


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