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();
}
--
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