syzbot


KASAN: slab-use-after-free Read in mgmt_remove_adv_monitor_complete (3)

Status: upstream: reported C repro on 2025/05/14 04:27
Subsystems: bluetooth
[Documentation on labels]
Reported-by: syzbot+feb0dc579bbe30a13190@syzkaller.appspotmail.com
Fix commit: Bluetooth: MGMT: Fix UAF on mgmt_remove_adv_monitor_complete
Patched on: [ci-qemu-gce-upstream-auto ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-net-this-kasan-gce ci-upstream-rust-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-qemu-native-arm64-kvm ci-qemu2-riscv64 ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce]
First crash: 39d, last: 12d
Discussions (3)
Title Replies (including bot) Last reply
[syzbot] [bluetooth?] KASAN: slab-use-after-free Read in hci_sock_get_channel 0 (6) 2025/06/03 20:32
[syzbot] [bluetooth?] KASAN: slab-use-after-free Read in mgmt_remove_adv_monitor_complete (3) 0 (8) 2025/06/03 20:30
[syzbot] [bluetooth?] BUG: corrupted list in mgmt_pending_remove 1 (6) 2025/06/02 18:02
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: slab-use-after-free Read in mgmt_remove_adv_monitor_complete (2) bluetooth 1 171d 167d 0/29 auto-obsoleted due to no activity on 2025/04/08 14:04
upstream KASAN: slab-use-after-free Read in mgmt_remove_adv_monitor_complete bluetooth 1 266d 247d 0/29 auto-obsoleted due to no activity on 2024/11/24 12:41
Last patch testing requests (11)
Created Duration User Patch Repo Result
2025/06/03 20:30 20m luiz.dentz@gmail.com patch upstream OK log
2025/06/02 18:00 20m luiz.dentz@gmail.com patch upstream report log
2025/05/28 19:03 20m luiz.dentz@gmail.com patch upstream OK log
2025/05/24 04:48 20m retest repro upstream report log
2025/05/23 08:20 20m dmantipov@yandex.ru patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 94305e83eccb3120c921cd3a015cd74731140bac OK log
2025/05/20 13:30 20m dmantipov@yandex.ru patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git a5806cd506af5a7c19bcd596e4708b5c464bfd21 OK log
2025/05/18 07:26 20m hdanton@sina.com patch upstream OK log
2025/05/18 04:47 20m hdanton@sina.com patch upstream report log
2025/05/17 23:28 13m hdanton@sina.com patch upstream error
2025/05/14 11:43 14m hdanton@sina.com patch upstream error
2025/05/14 07:10 9m dmantipov@yandex.ru patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 9f35e33144ae5377d6a8de86dd3bd4d995c6ac65 error

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in mgmt_remove_adv_monitor_complete+0xe5/0x540 net/bluetooth/mgmt.c:5407
Read of size 8 at addr ffff88804c336818 by task kworker/u5:5/5358

CPU: 0 UID: 0 PID: 5358 Comm: kworker/u5:5 Not tainted 6.15.0-syzkaller-12426-ge271ed52b344 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: hci0 hci_cmd_sync_work
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xd2/0x2b0 mm/kasan/report.c:521
 kasan_report+0x118/0x150 mm/kasan/report.c:634
 mgmt_remove_adv_monitor_complete+0xe5/0x540 net/bluetooth/mgmt.c:5407
 hci_cmd_sync_work+0x261/0x3a0 net/bluetooth/hci_sync.c:334
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 9602:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4359
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 mgmt_pending_new+0x65/0x240 net/bluetooth/mgmt_util.c:252
 mgmt_pending_add+0x34/0x120 net/bluetooth/mgmt_util.c:279
 remove_adv_monitor+0x103/0x1b0 net/bluetooth/mgmt.c:5455
 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:712 [inline]
 __sock_sendmsg+0x219/0x270 net/socket.c:727
 sock_write_iter+0x258/0x330 net/socket.c:1131
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x54b/0xa90 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/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 9609:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2381 [inline]
 slab_free mm/slub.c:4643 [inline]
 kfree+0x18e/0x440 mm/slub.c:4842
 mgmt_pending_foreach+0xc9/0x120 net/bluetooth/mgmt_util.c:242
 mgmt_index_removed+0x10d/0x2f0 net/bluetooth/mgmt.c:9367
 hci_sock_bind+0xbe9/0x1000 net/bluetooth/hci_sock.c:1314
 __sys_bind_socket net/socket.c:1810 [inline]
 __sys_bind+0x2c6/0x3e0 net/socket.c:1841
 __do_sys_bind net/socket.c:1846 [inline]
 __se_sys_bind net/socket.c:1844 [inline]
 __x64_sys_bind+0x7a/0x90 net/socket.c:1844
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88804c336800
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 24 bytes inside of
 freed 96-byte region [ffff88804c336800, ffff88804c336860)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4c336
anon flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000000 ffff88801a441280 0000000000000000 dead000000000001
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 4756, tgid 4756 (kworker/0:3), ts 139942970900, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704
 prep_new_page mm/page_alloc.c:1712 [inline]
 get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3669
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419
 alloc_slab_page mm/slub.c:2451 [inline]
 allocate_slab+0x8a/0x3b0 mm/slub.c:2619
 new_slab mm/slub.c:2673 [inline]
 ___slab_alloc+0xbfc/0x1480 mm/slub.c:3859
 __slab_alloc mm/slub.c:3949 [inline]
 __slab_alloc_node mm/slub.c:4024 [inline]
 slab_alloc_node mm/slub.c:4185 [inline]
 __kmalloc_cache_noprof+0x296/0x3d0 mm/slub.c:4354
 kmalloc_noprof include/linux/slab.h:905 [inline]
 dst_cow_metrics_generic+0x56/0x1c0 net/core/dst.c:193
 dst_metrics_write_ptr include/net/dst.h:133 [inline]
 dst_metric_set include/net/dst.h:194 [inline]
 icmp6_dst_alloc+0x264/0x420 net/ipv6/route.c:3337
 mld_sendpack+0x678/0xd80 net/ipv6/mcast.c:1857
 mld_send_cr net/ipv6/mcast.c:2169 [inline]
 mld_ifc_work+0x835/0xde0 net/ipv6/mcast.c:2702
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88804c336700: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff88804c336780: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
>ffff88804c336800: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                            ^
 ffff88804c336880: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
 ffff88804c336900: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
==================================================================

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/06 20:36 upstream e271ed52b344 3d899f2c .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in mgmt_remove_adv_monitor_complete
2025/06/01 07:10 upstream 4cb6c8af8591 3d2f584d .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in mgmt_remove_adv_monitor_complete
2025/05/30 06:01 upstream e0797d3b91de 3d2f584d .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in mgmt_remove_adv_monitor_complete
2025/05/30 04:04 upstream e0797d3b91de 3d2f584d .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in mgmt_remove_adv_monitor_complete
2025/05/10 04:20 upstream ea34704d6ad7 77908e5f .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in mgmt_remove_adv_monitor_complete
* Struck through repros no longer work on HEAD.