[syzbot] [bluetooth?] KASAN: slab-use-after-free Read in mgmt_pending_remove

[syzbot] [bluetooth?] KASAN: slab-use-after-free Read in mgmt_pending_remove

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    4001bda0cc91 Merge branch 'selftests-vsock-refactor-and-im..
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=17f2897c580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=4dda49799a90cd0f
dashboard link: https://syzkaller.appspot.com/bug?extid=9aa47cd4633a3cf92a80
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11a21c12580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f1a9e5dda198/disk-4001bda0.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e0d7f0aa5468/vmlinux-4001bda0.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9cef7d2ebe50/bzImage-4001bda0.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9aa47cd4633a3cf92a80@syzkaller.appspotmail.com

RAX: ffffffffffffffda RBX: 00007f5543fe5fa0 RCX: 00007f5543d8f6c9
RDX: 0000000000000007 RSI: 0000200000000000 RDI: 0000000000000005
RBP: 00007f5544b69090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007f5543fe6038 R14: 00007f5543fe5fa0 R15: 00007ffe72e0a568
 </TASK>
Bluetooth: hci0: no memory for command
==================================================================
BUG: KASAN: slab-use-after-free in mgmt_pending_remove+0x3b/0x210 net/bluetooth/mgmt_util.c:316
Read of size 8 at addr ffff888077164818 by task syz.0.17/5989

CPU: 0 UID: 0 PID: 5989 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 mgmt_pending_remove+0x3b/0x210 net/bluetooth/mgmt_util.c:316
 set_link_security+0x5c2/0x710 net/bluetooth/mgmt.c:1918
 hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719
 hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 sock_write_iter+0x279/0x360 net/socket.c:1195
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x5c9/0xb30 fs/read_write.c:686
 ksys_write+0x145/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5543d8f6c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5544b69038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5543fe5fa0 RCX: 00007f5543d8f6c9
RDX: 0000000000000007 RSI: 0000200000000000 RDI: 0000000000000005
RBP: 00007f5544b69090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007f5543fe6038 R14: 00007f5543fe5fa0 R15: 00007ffe72e0a568
 </TASK>

Allocated by task 5989:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417
 kasan_kmalloc include/linux/kasan.h:262 [inline]
 __kmalloc_cache_noprof+0x3d5/0x6f0 mm/slub.c:5763
 kmalloc_noprof include/linux/slab.h:957 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 mgmt_pending_new+0x65/0x1e0 net/bluetooth/mgmt_util.c:269
 mgmt_pending_add+0x35/0x140 net/bluetooth/mgmt_util.c:296
 set_link_security+0x557/0x710 net/bluetooth/mgmt.c:1910
 hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719
 hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 sock_write_iter+0x279/0x360 net/socket.c:1195
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x5c9/0xb30 fs/read_write.c:686
 ksys_write+0x145/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5991:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587
 kasan_save_free_info mm/kasan/kasan.h:406 [inline]
 poison_slab_object mm/kasan/common.c:252 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2539 [inline]
 slab_free mm/slub.c:6630 [inline]
 kfree+0x19a/0x6d0 mm/slub.c:6837
 mgmt_pending_free net/bluetooth/mgmt_util.c:311 [inline]
 mgmt_pending_foreach+0x30d/0x380 net/bluetooth/mgmt_util.c:257
 mgmt_index_removed+0x112/0x2f0 net/bluetooth/mgmt.c:9477
 hci_sock_bind+0xbe9/0x1000 net/bluetooth/hci_sock.c:1314
 __sys_bind_socket net/socket.c:1874 [inline]
 __sys_bind+0x2c6/0x3e0 net/socket.c:1905
 __do_sys_bind net/socket.c:1910 [inline]
 __se_sys_bind net/socket.c:1908 [inline]
 __x64_sys_bind+0x7a/0x90 net/socket.c:1908
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888077164800
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 24 bytes inside of
 freed 96-byte region [ffff888077164800, ffff888077164860)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x77164
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801a026280 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080200020 00000000f5000000 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1098, tgid 1098 (kworker/u8:6), ts 87994876358, free_ts 87976357652
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850
 prep_new_page mm/page_alloc.c:1858 [inline]
 get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3884
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:3055 [inline]
 allocate_slab+0x96/0x350 mm/slub.c:3228
 new_slab mm/slub.c:3282 [inline]
 ___slab_alloc+0xe94/0x18a0 mm/slub.c:4651
 __slab_alloc+0x65/0x100 mm/slub.c:4770
 __slab_alloc_node mm/slub.c:4846 [inline]
 slab_alloc_node mm/slub.c:5268 [inline]
 __kmalloc_cache_noprof+0x411/0x6f0 mm/slub.c:5758
 kmalloc_noprof include/linux/slab.h:957 [inline]
 dst_cow_metrics_generic+0x56/0x1c0 net/core/dst.c:193
 dst_metrics_write_ptr include/net/dst.h:136 [inline]
 dst_metric_set include/net/dst.h:197 [inline]
 icmp6_dst_alloc+0x264/0x420 net/ipv6/route.c:3335
 ndisc_send_skb+0x3f1/0x1510 net/ipv6/ndisc.c:491
 ndisc_send_ns+0xcb/0x150 net/ipv6/ndisc.c:670
 addrconf_dad_work+0xaae/0x14b0 net/ipv6/addrconf.c:4282
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
 kthread+0x711/0x8a0 kernel/kthread.c:463
page last free pid 1113 tgid 1113 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2906
 __slab_free+0x2e7/0x390 mm/slub.c:5962
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:352
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4970 [inline]
 slab_alloc_node mm/slub.c:5280 [inline]
 kmem_cache_alloc_node_noprof+0x433/0x710 mm/slub.c:5332
 __alloc_skb+0x112/0x2d0 net/core/skbuff.c:664
 alloc_skb include/linux/skbuff.h:1383 [inline]
 nlmsg_new include/net/netlink.h:1055 [inline]
 nl80211_send_ibss_bssid+0x8d/0x430 net/wireless/nl80211.c:19952
 __cfg80211_ibss_joined+0x34a/0x440 net/wireless/ibss.c:50
 cfg80211_process_wdev_events+0x38a/0x4f0 net/wireless/util.c:1143
 cfg80211_process_rdev_events+0xa1/0x110 net/wireless/util.c:1170
 cfg80211_event_work+0x31/0x70 net/wireless/core.c:334
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158

Memory state around the buggy address:
 ffff888077164700: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
 ffff888077164780: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
>ffff888077164800: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                            ^
 ffff888077164880: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
 ffff888077164900: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Read in mgmt_pending_remove

[Edward Adam Davis]

#syz test

diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 262bf984d2aa..33e725798c34 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -9474,7 +9474,9 @@ void mgmt_index_removed(struct hci_dev *hdev)
 	if (hci_test_quirk(hdev, HCI_QUIRK_RAW_DEVICE))
 		return;
 
+	hci_dev_lock(hdev);
 	mgmt_pending_foreach(0, hdev, true, cmd_complete_rsp, &match);
+	hci_dev_unlock(hdev);
 
 	if (hci_dev_test_flag(hdev, HCI_UNCONFIGURED)) {
 		mgmt_index_event(MGMT_EV_UNCONF_INDEX_REMOVED, hdev, NULL, 0,

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Read in mgmt_pending_remove

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

022][ T5851]  ? kmem_cache_free+0x19b/0x690
[   98.045044][ T5851]  do_exit+0x6b5/0x2300
[   98.045064][ T5851]  ? do_raw_spin_lock+0x121/0x290
[   98.045083][ T5851]  ? __pfx_do_exit+0x10/0x10
[   98.045105][ T5851]  do_group_exit+0x21c/0x2d0
[   98.045124][ T5851]  ? lockdep_hardirqs_on+0x9c/0x150
[   98.045138][ T5851]  get_signal+0x1285/0x1340
[   98.045158][ T5851]  arch_do_signal_or_restart+0xa0/0x790
[   98.045181][ T5851]  ? __pfx_arch_do_signal_or_restart+0x10/0x10
[   98.045206][ T5851]  ? exit_to_user_mode_loop+0x40/0x130
[   98.045220][ T5851]  exit_to_user_mode_loop+0x72/0x130
[   98.045233][ T5851]  do_syscall_64+0x2bd/0xfa0
[   98.045247][ T5851]  ? lockdep_hardirqs_on+0x9c/0x150
[   98.045260][ T5851]  ? entry_SYSCALL_64_after_hwframe+0x77/0x7f
[   98.045274][ T5851]  ? clear_bhb_loop+0x60/0xb0
[   98.045289][ T5851]  entry_SYSCALL_64_after_hwframe+0x77/0x7f
[   98.045302][ T5851] RIP: 0033:0x7f01e85915e7
[   98.045315][ T5851] Code: Unable to access opcode bytes at 0x7f01e85915bd.
[   98.045322][ T5851] RSP: 002b:00007ffd3b28dfa8 EFLAGS: 00000202 ORIG_RAX: 0000000000000029
[   98.045339][ T5851] RAX: 0000000000000003 RBX: 00007f01e87b1300 RCX: 00007f01e85915e7
[   98.045350][ T5851] RDX: 0000000000000006 RSI: 0000000000000001 RDI: 0000000000000002
[   98.045358][ T5851] RBP: 00007ffd3b28e6cc R08: 0000000000000000 R09: 00007ffd3b28e3d7
[   98.045367][ T5851] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000001
[   98.045375][ T5851] R13: 00007f01e87b1280 R14: 0000000000000000 R15: 00007ffd3b28e720
[   98.045390][ T5851]  </TASK>
[   98.378540][   T12] wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[   98.386690][   T12] wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
[   98.389814][ T5858] ieee80211 phy4: Selected rate control algorithm 'minstrel_ht'
[   98.411678][   T79] wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[   98.419746][   T79] wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
[   99.353370][ T5894] chnl_net:caif_netlink_parms(): no params data found
[   99.418057][ T5894] bridge0: port 1(bridge_slave_0) entered blocking state
[   99.425428][ T5894] bridge0: port 1(bridge_slave_0) entered disabled state
[   99.432627][ T5894] bridge_slave_0: entered allmulticast mode
[   99.439520][ T5894] bridge_slave_0: entered promiscuous mode
[   99.447024][ T5894] bridge0: port 2(bridge_slave_1) entered blocking state
[   99.454503][ T5894] bridge0: port 2(bridge_slave_1) entered disabled state
[   99.462695][ T5894] bridge_slave_1: entered allmulticast mode
[   99.470917][ T5894] bridge_slave_1: entered promiscuous mode
[   99.501077][ T5894] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
[   99.512217][ T5894] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
[   99.532942][ T5894] team0: Port device team_slave_0 added
[   99.540510][ T5894] team0: Port device team_slave_1 added
[   99.561110][ T5894] batman_adv: batadv0: Adding interface: batadv_slave_0
[   99.568213][ T5894] batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[   99.594552][ T5894] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
[   99.606103][ T5894] batman_adv: batadv0: Adding interface: batadv_slave_1
[   99.613063][ T5894] batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[   99.639753][ T5894] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
[   99.674242][ T5894] hsr_slave_0: entered promiscuous mode
[   99.680522][ T5894] hsr_slave_1: entered promiscuous mode
[   99.748239][ T5894] netdevsim netdevsim0 netdevsim0: renamed from eth0
[   99.757893][ T5894] netdevsim netdevsim0 netdevsim1: renamed from eth1
[   99.767651][ T5894] netdevsim netdevsim0 netdevsim2: renamed from eth2
[   99.776497][ T5894] netdevsim netdevsim0 netdevsim3: renamed from eth3
[   99.794605][ T5894] bridge0: port 2(bridge_slave_1) entered blocking state
[   99.801694][ T5894] bridge0: port 2(bridge_slave_1) entered forwarding state
[   99.809289][ T5894] bridge0: port 1(bridge_slave_0) entered blocking state
[   99.816402][ T5894] bridge0: port 1(bridge_slave_0) entered forwarding state
[   99.849208][ T5894] 8021q: adding VLAN 0 to HW filter on device bond0
[   99.861911][   T79] bridge0: port 1(bridge_slave_0) entered disabled state
[   99.870963][   T79] bridge0: port 2(bridge_slave_1) entered disabled state
[   99.882660][ T5894] 8021q: adding VLAN 0 to HW filter on device team0
[   99.895117][   T50] bridge0: port 1(bridge_slave_0) entered blocking state
[   99.902499][   T50] bridge0: port 1(bridge_slave_0) entered forwarding state
[   99.914797][   T79] bridge0: port 2(bridge_slave_1) entered blocking state
[   99.921907][   T79] bridge0: port 2(bridge_slave_1) entered forwarding state
[  100.027173][ T5894] 8021q: adding VLAN 0 to HW filter on device batadv0
[  100.059727][ T5894] veth0_vlan: entered promiscuous mode
[  100.069248][ T5894] veth1_vlan: entered promiscuous mode
[  100.089179][ T5894] veth0_macvtap: entered promiscuous mode
[  100.098172][ T5894] veth1_macvtap: entered promiscuous mode
[  100.110792][ T5894] batman_adv: batadv0: Interface activated: batadv_slave_0
[  100.123421][ T5894] batman_adv: batadv0: Interface activated: batadv_slave_1
[  100.135149][   T50] netdevsim netdevsim0 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
[  100.144394][   T50] netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
[  100.154732][   T50] netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
[  100.163861][   T50] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
[  100.247849][   T79] netdevsim netdevsim0 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[  100.282107][   T79] netdevsim netdevsim0 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[  100.345609][   T79] netdevsim netdevsim0 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[  100.431459][   T79] netdevsim netdevsim0 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
2025/11/16 08:20:35 executed programs: 0
[  100.990449][ T5146] Bluetooth: hci1: unexpected cc 0x0c03 length: 249 > 1
[  100.998317][ T5146] Bluetooth: hci1: unexpected cc 0x1003 length: 249 > 9
[  101.007725][ T5146] Bluetooth: hci1: unexpected cc 0x1001 length: 249 > 9
[  101.015889][ T5146] Bluetooth: hci1: unexpected cc 0x0c23 length: 249 > 4
[  101.024741][ T5146] Bluetooth: hci1: unexpected cc 0x0c38 length: 249 > 2
[  101.118697][ T5934] chnl_net:caif_netlink_parms(): no params data found
[  101.161430][ T5934] bridge0: port 1(bridge_slave_0) entered blocking state
[  101.169408][ T5934] bridge0: port 1(bridge_slave_0) entered disabled state
[  101.176899][ T5934] bridge_slave_0: entered allmulticast mode
[  101.183902][ T5934] bridge_slave_0: entered promiscuous mode
[  101.191277][ T5934] bridge0: port 2(bridge_slave_1) entered blocking state
[  101.198558][ T5934] bridge0: port 2(bridge_slave_1) entered disabled state
[  101.205858][ T5934] bridge_slave_1: entered allmulticast mode
[  101.212895][ T5934] bridge_slave_1: entered promiscuous mode
[  101.235387][ T5934] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
[  101.247326][ T5934] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
[  101.273904][ T5934] team0: Port device team_slave_0 added
[  101.280932][ T5934] team0: Port device team_slave_1 added
[  101.298158][ T5934] batman_adv: batadv0: Adding interface: batadv_slave_0
[  101.305607][ T5934] batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[  101.332185][ T5934] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
[  101.344400][ T5934] batman_adv: batadv0: Adding interface: batadv_slave_1
[  101.351729][ T5934] batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[  101.379297][ T5934] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
[  101.409545][ T5934] hsr_slave_0: entered promiscuous mode
[  101.416136][ T5934] hsr_slave_1: entered promiscuous mode
[  101.422075][ T5934] debugfs: 'hsr0' already exists in 'hsr'
[  101.428232][ T5934] Cannot create hsr debugfs directory
[  103.083403][ T5852] Bluetooth: hci1: command tx timeout
[  103.408906][   T79] bridge_slave_1: left allmulticast mode
[  103.416318][   T79] bridge_slave_1: left promiscuous mode
[  103.422340][   T79] bridge0: port 2(bridge_slave_1) entered disabled state
[  103.434700][   T79] bridge_slave_0: left allmulticast mode
[  103.440485][   T79] bridge_slave_0: left promiscuous mode
[  103.446862][   T79] bridge0: port 1(bridge_slave_0) entered disabled state
[  103.557628][   T79] bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
[  103.568674][   T79] bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
[  103.578654][   T79] bond0 (unregistering): Released all slaves
[  103.688535][   T79] hsr_slave_0: left promiscuous mode
[  103.699423][   T79] hsr_slave_1: left promiscuous mode
[  103.705766][   T79] batman_adv: batadv0: Interface deactivated: batadv_slave_0
[  103.714781][   T79] batman_adv: batadv0: Removing interface: batadv_slave_0
[  103.722702][   T79] batman_adv: batadv0: Interface deactivated: batadv_slave_1
[  103.730697][   T79] batman_adv: batadv0: Removing interface: batadv_slave_1
[  103.742099][   T79] veth1_macvtap: left promiscuous mode
[  103.748282][   T79] veth0_macvtap: left promiscuous mode
[  103.753965][   T79] veth1_vlan: left promiscuous mode
[  103.759445][   T79] veth0_vlan: left promiscuous mode
[  103.921563][   T79] team0 (unregistering): Port device team_slave_1 removed
[  103.932559][   T79] team0 (unregistering): Port device team_slave_0 removed
[  104.214906][ T5934] netdevsim netdevsim0 netdevsim0: renamed from eth0
[  104.228969][ T5934] netdevsim netdevsim0 netdevsim1: renamed from eth1
[  104.239124][ T5934] netdevsim netdevsim0 netdevsim2: renamed from eth2
[  104.249179][ T5934] netdevsim netdevsim0 netdevsim3: renamed from eth3
[  104.341776][ T5934] 8021q: adding VLAN 0 to HW filter on device bond0
[  104.358525][ T5934] 8021q: adding VLAN 0 to HW filter on device team0
[  104.375257][ T1085] bridge0: port 1(bridge_slave_0) entered blocking state
[  104.382582][ T1085] bridge0: port 1(bridge_slave_0) entered forwarding state
[  104.401872][ T1085] bridge0: port 2(bridge_slave_1) entered blocking state
[  104.409195][ T1085] bridge0: port 2(bridge_slave_1) entered forwarding state
[  104.738722][ T5934] 8021q: adding VLAN 0 to HW filter on device batadv0
[  104.765852][ T5934] veth0_vlan: entered promiscuous mode
[  104.775508][ T5934] veth1_vlan: entered promiscuous mode
[  104.796938][ T5934] veth0_macvtap: entered promiscuous mode
[  104.805872][ T5934] veth1_macvtap: entered promiscuous mode
[  104.818189][ T5934] batman_adv: batadv0: Interface activated: batadv_slave_0
[  104.830594][ T5934] batman_adv: batadv0: Interface activated: batadv_slave_1
[  104.844301][ T1144] netdevsim netdevsim0 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
[  104.854320][   T12] netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
[  104.866000][   T12] netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
[  104.874997][   T12] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
[  104.897274][ T5934] ieee80211 phy5: Selected rate control algorithm 'minstrel_ht'
[  104.916565][ T1085] wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[  104.917918][ T5934] ieee80211 phy6: Selected rate control algorithm 'minstrel_ht'
[  104.928653][ T1085] wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
SYZFAIL: failed to recv rpc
fd=3 want=4 recv=0 n=0 (errno 9: Bad file descriptor)
[  104.951336][ T1085] wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[  104.959711][ T1085] wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50


syzkaller build log:
go env (err=<nil>)
AR='ar'
CC='gcc'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='g++'
GCCGO='gccgo'
GO111MODULE='auto'
GOAMD64='v1'
GOARCH='amd64'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/syzkaller/.cache/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/syzkaller/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build2571666063=/tmp/go-build -gno-record-gcc-switches'
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMOD='/syzkaller/jobs-2/linux/gopath/src/github.com/google/syzkaller/go.mod'
GOMODCACHE='/syzkaller/jobs-2/linux/gopath/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/syzkaller/jobs-2/linux/gopath'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/syzkaller/.config/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.24.4'
GOWORK=''
PKG_CONFIG='pkg-config'

git status (err=<nil>)
HEAD detached at 07e030dea
nothing to commit, working tree clean


tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
go list -f '{{.Stale}}' -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=07e030dea6e6d9ca88b75bb3be2810f47083b328 -X github.com/google/syzkaller/prog.gitRevisionDate=20251112-115923"  ./sys/syz-sysgen | grep -q false || go install -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=07e030dea6e6d9ca88b75bb3be2810f47083b328 -X github.com/google/syzkaller/prog.gitRevisionDate=20251112-115923"  ./sys/syz-sysgen
make .descriptions
tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
bin/syz-sysgen
touch .descriptions
GOOS=linux GOARCH=amd64 go build -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=07e030dea6e6d9ca88b75bb3be2810f47083b328 -X github.com/google/syzkaller/prog.gitRevisionDate=20251112-115923"  -o ./bin/linux_amd64/syz-execprog github.com/google/syzkaller/tools/syz-execprog
mkdir -p ./bin/linux_amd64
g++ -o ./bin/linux_amd64/syz-executor executor/executor.cc \
	-m64 -O2 -pthread -Wall -Werror -Wparentheses -Wunused-const-variable -Wframe-larger-than=16384 -Wno-stringop-overflow -Wno-array-bounds -Wno-format-overflow -Wno-unused-but-set-variable -Wno-unused-command-line-argument -static-pie -std=c++17 -I. -Iexecutor/_include   -DGOOS_linux=1 -DGOARCH_amd64=1 \
	-DHOSTGOOS_linux=1 -DGIT_REVISION=\"07e030dea6e6d9ca88b75bb3be2810f47083b328\"
/usr/bin/ld: /tmp/ccL2C3R3.o: in function `Connection::Connect(char const*, char const*)':
executor.cc:(.text._ZN10Connection7ConnectEPKcS1_[_ZN10Connection7ConnectEPKcS1_]+0x104): warning: Using 'gethostbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
./tools/check-syzos.sh 2>/dev/null


Error text is too large and was truncated, full error text is at:
https://syzkaller.appspot.com/x/error.txt?x=13ac6658580000


Tested on:

commit:         c9dfb92d Merge branch 'mlx5-next' of git://git.kernel...
git tree:       net-next
kernel config:  https://syzkaller.appspot.com/x/.config?x=4dda49799a90cd0f
dashboard link: https://syzkaller.appspot.com/bug?extid=9aa47cd4633a3cf92a80
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=14445212580000

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Read in mgmt_pending_remove

[Edward Adam Davis]

#syz test

diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index fc866759910d..ad19022ae127 100644
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -1311,7 +1311,9 @@ static int hci_sock_bind(struct socket *sock, struct sockaddr *addr,
 			goto done;
 		}
 
+		hci_dev_lock(hdev);
 		mgmt_index_removed(hdev);
+		hci_dev_unlock(hdev);
 
 		err = hci_dev_open(hdev->id);
 		if (err) {

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Read in mgmt_pending_remove

[syzbot]

Hello,

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

Reported-by: syzbot+9aa47cd4633a3cf92a80@syzkaller.appspotmail.com
Tested-by: syzbot+9aa47cd4633a3cf92a80@syzkaller.appspotmail.com

Tested on:

commit:         c9dfb92d Merge branch 'mlx5-next' of git://git.kernel...
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1629a212580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=4dda49799a90cd0f
dashboard link: https://syzkaller.appspot.com/bug?extid=9aa47cd4633a3cf92a80
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1234dd32580000

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

[PATCH] Bluetooth: hci_sock: Prevent race in socket write iter and sock bind

[Edward Adam Davis]

There is a potential race condition between sock bind and socket write
iter. bind may free the same cmd via mgmt_pending before write iter sends
the cmd, just as syzbot reported in UAF[1].

Here we use hci_dev_lock to synchronize the two, thereby avoiding the
UAF mentioned in [1].

[1]
syzbot reported:
BUG: KASAN: slab-use-after-free in mgmt_pending_remove+0x3b/0x210 net/bluetooth/mgmt_util.c:316
Read of size 8 at addr ffff888077164818 by task syz.0.17/5989
Call Trace:
 mgmt_pending_remove+0x3b/0x210 net/bluetooth/mgmt_util.c:316
 set_link_security+0x5c2/0x710 net/bluetooth/mgmt.c:1918
 hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719
 hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 sock_write_iter+0x279/0x360 net/socket.c:1195

Allocated by task 5989:
 mgmt_pending_add+0x35/0x140 net/bluetooth/mgmt_util.c:296
 set_link_security+0x557/0x710 net/bluetooth/mgmt.c:1910
 hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719
 hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 sock_write_iter+0x279/0x360 net/socket.c:1195

Freed by task 5991:
 mgmt_pending_free net/bluetooth/mgmt_util.c:311 [inline]
 mgmt_pending_foreach+0x30d/0x380 net/bluetooth/mgmt_util.c:257
 mgmt_index_removed+0x112/0x2f0 net/bluetooth/mgmt.c:9477
 hci_sock_bind+0xbe9/0x1000 net/bluetooth/hci_sock.c:1314

Fixes: 6fe26f694c82 ("Bluetooth: MGMT: Protect mgmt_pending list with its own lock")
Reported-by: syzbot+9aa47cd4633a3cf92a80@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=9aa47cd4633a3cf92a80
Tested-by: syzbot+9aa47cd4633a3cf92a80@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
---
 net/bluetooth/hci_sock.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index fc866759910d..ad19022ae127 100644
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -1311,7 +1311,9 @@ static int hci_sock_bind(struct socket *sock, struct sockaddr *addr,
 			goto done;
 		}
 
+		hci_dev_lock(hdev);
 		mgmt_index_removed(hdev);
+		hci_dev_unlock(hdev);
 
 		err = hci_dev_open(hdev->id);
 		if (err) {
-- 
2.43.0

Re: [PATCH] Bluetooth: hci_sock: Prevent race in socket write iter and sock bind

[patchwork-bot+bluetooth]

Hello:

This patch was applied to bluetooth/bluetooth-next.git (master)
by Luiz Augusto von Dentz <luiz.von.dentz@intel.com>:

On Sun, 16 Nov 2025 17:04:43 +0800 you wrote:
> There is a potential race condition between sock bind and socket write
> iter. bind may free the same cmd via mgmt_pending before write iter sends
> the cmd, just as syzbot reported in UAF[1].
> 
> Here we use hci_dev_lock to synchronize the two, thereby avoiding the
> UAF mentioned in [1].
> 
> [...]

Here is the summary with links:
  - Bluetooth: hci_sock: Prevent race in socket write iter and sock bind
    https://git.kernel.org/bluetooth/bluetooth-next/c/1f738d68430c

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html