KASAN: use-after-free Read in mgmt_pending_remove

Status: fixed on 2023/02/24 14:17
Subsystems: bluetooth
[Documentation on labels]
Reported-by: syzbot+915a8416bf15895b8e07@syzkaller.appspotmail.com
Fix commit: 3cfbc6ac22d6 Bluetooth: hci_sync: fix double mgmt_pending_free() in remove_adv_monitor() Bluetooth: hci_sync: fix double mgmt_pending_free() in remove_adv_monitor()
First crash: 1450d, last: 1426d
Cause bisection: introduced by (bisect log) [release commit]:
commit 3d7cb6b04c3f3115719235cc6866b10326de34cd
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date: Sun Jul 31 21:03:01 2022 +0000

  Linux 5.19

Crash: WARNING: ODEBUG bug in netdev_run_todo (log)
Repro: C syz .config
  
▶ ▼ Discussions (2)
Title Replies (including bot) Last reply
[PATCH] Bluetooth: hci_sync: fix double mgmt_pending_free() in remove_adv_monitor() 2 (2) 2022/08/17 18:52
[syzbot] KASAN: use-after-free Read in mgmt_pending_remove 0 (1) 2022/08/17 10:42
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 KASAN: use-after-free Read in mgmt_pending_remove 19 1 558d 558d 0/3 auto-obsoleted due to no activity on 2025/05/01 22:08
linux-6.1 KASAN: use-after-free Read in mgmt_pending_remove 19 1 275d 275d 0/3 auto-obsoleted due to no activity on 2026/02/08 16:52
upstream KASAN: slab-use-after-free Read in mgmt_pending_remove bluetooth 19 syz 2 263d 259d 29/29 fixed on 2026/01/07 12:29
linux-5.15 BUG: corrupted list in mgmt_pending_remove 8 1 125d 125d 0/3 auto-obsoleted due to no activity on 2026/07/08 05:18
upstream BUG: corrupted list in mgmt_pending_remove bluetooth 19 syz, C error 44 429d 700d 29/29 fixed on 2025/08/06 17:37
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
2022/08/17 11:31 18m hdanton@sina.com patch https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git 40b4ac880e21 OK log

Sample crash report:
Bluetooth: MGMT ver 1.22
==================================================================
BUG: KASAN: use-after-free in __list_del_entry_valid+0xde/0x110 lib/list_debug.c:46
Read of size 8 at addr ffff8880261de088 by task syz-executor114/3637

CPU: 0 PID: 3637 Comm: syz-executor114 Not tainted 6.0.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:317 [inline]
 print_report.cold+0x2ba/0x719 mm/kasan/report.c:433
 kasan_report+0xb1/0x1e0 mm/kasan/report.c:495
 __list_del_entry_valid+0xde/0x110 lib/list_debug.c:46
 __list_del_entry include/linux/list.h:134 [inline]
 list_del include/linux/list.h:148 [inline]
 mgmt_pending_remove+0x1a/0x160 net/bluetooth/mgmt_util.c:314
 remove_adv_monitor+0x1b9/0x1c0 net/bluetooth/mgmt.c:5057
 hci_mgmt_cmd net/bluetooth/hci_sock.c:1619 [inline]
 hci_sock_sendmsg+0x1dee/0x2490 net/bluetooth/hci_sock.c:1739
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:734
 sock_write_iter+0x291/0x3d0 net/socket.c:1108
 call_write_iter include/linux/fs.h:2187 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x9e9/0xdd0 fs/read_write.c:578
 ksys_write+0x1e8/0x250 fs/read_write.c:631
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7ff474058bf9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 01 16 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe9e8d0558 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007ff474058bf9
RDX: 0000000000000008 RSI: 0000000020000080 RDI: 0000000000000004
RBP: 00007ffe9e8d0580 R08: 0000000000000001 R09: 00007ffe9e8d0590
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000072 R14: 00007ffe9e8d05a0 R15: 0000000000000000
 </TASK>

Allocated by task 3637:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:437 [inline]
 ____kasan_kmalloc mm/kasan/common.c:516 [inline]
 ____kasan_kmalloc mm/kasan/common.c:475 [inline]
 __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:525
 kmalloc include/linux/slab.h:600 [inline]
 kzalloc include/linux/slab.h:733 [inline]
 mgmt_pending_new+0x57/0x290 net/bluetooth/mgmt_util.c:269
 mgmt_pending_add+0x34/0x160 net/bluetooth/mgmt_util.c:296
 remove_adv_monitor+0x120/0x1c0 net/bluetooth/mgmt.c:5040
 hci_mgmt_cmd net/bluetooth/hci_sock.c:1619 [inline]
 hci_sock_sendmsg+0x1dee/0x2490 net/bluetooth/hci_sock.c:1739
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:734
 sock_write_iter+0x291/0x3d0 net/socket.c:1108
 call_write_iter include/linux/fs.h:2187 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x9e9/0xdd0 fs/read_write.c:578
 ksys_write+0x1e8/0x250 fs/read_write.c:631
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Freed by task 3637:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track+0x21/0x30 mm/kasan/common.c:45
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
 ____kasan_slab_free mm/kasan/common.c:367 [inline]
 ____kasan_slab_free+0x166/0x1c0 mm/kasan/common.c:329
 kasan_slab_free include/linux/kasan.h:200 [inline]
 slab_free_hook mm/slub.c:1754 [inline]
 slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1780
 slab_free mm/slub.c:3534 [inline]
 kfree+0xe2/0x580 mm/slub.c:4562
 remove_adv_monitor+0x18b/0x1c0 net/bluetooth/mgmt.c:5050
 hci_mgmt_cmd net/bluetooth/hci_sock.c:1619 [inline]
 hci_sock_sendmsg+0x1dee/0x2490 net/bluetooth/hci_sock.c:1739
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:734
 sock_write_iter+0x291/0x3d0 net/socket.c:1108
 call_write_iter include/linux/fs.h:2187 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x9e9/0xdd0 fs/read_write.c:578
 ksys_write+0x1e8/0x250 fs/read_write.c:631
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

The buggy address belongs to the object at ffff8880261de080
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 8 bytes inside of
 96-byte region [ffff8880261de080, ffff8880261de0e0)

The buggy address belongs to the physical page:
page:ffffea0000987780 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x261de
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea00005b69c0 dead000000000004 ffff888011841780
raw: 0000000000000000 0000000080200020 00000001ffffffff 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 2970, tgid 2970 (udevd), ts 11531596738, free_ts 11167952196
 prep_new_page mm/page_alloc.c:2532 [inline]
 get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283
 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5515
 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2270
 alloc_slab_page mm/slub.c:1824 [inline]
 allocate_slab+0x27e/0x3d0 mm/slub.c:1969
 new_slab mm/slub.c:2029 [inline]
 ___slab_alloc+0x7f1/0xe10 mm/slub.c:3031
 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3118
 slab_alloc_node mm/slub.c:3209 [inline]
 slab_alloc mm/slub.c:3251 [inline]
 __kmalloc+0x32b/0x340 mm/slub.c:4420
 kmalloc include/linux/slab.h:605 [inline]
 kzalloc include/linux/slab.h:733 [inline]
 ext4_htree_store_dirent+0x89/0x5f0 fs/ext4/dir.c:474
 htree_dirblock_to_tree+0x734/0xcd0 fs/ext4/namei.c:1120
 ext4_htree_fill_tree+0x323/0xc30 fs/ext4/namei.c:1199
 ext4_dx_readdir fs/ext4/dir.c:597 [inline]
 ext4_readdir+0x1dfe/0x3870 fs/ext4/dir.c:142
 iterate_dir+0x56a/0x6f0 fs/readdir.c:65
 __do_sys_getdents64 fs/readdir.c:369 [inline]
 __se_sys_getdents64 fs/readdir.c:354 [inline]
 __x64_sys_getdents64+0x13a/0x2c0 fs/readdir.c:354
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1449 [inline]
 free_pcp_prepare+0x5e4/0xd20 mm/page_alloc.c:1499
 free_unref_page_prepare mm/page_alloc.c:3380 [inline]
 free_unref_page+0x19/0x4d0 mm/page_alloc.c:3476
 __vunmap+0x85d/0xd30 mm/vmalloc.c:2696
 free_work+0x58/0x70 mm/vmalloc.c:97
 process_one_work+0x991/0x1610 kernel/workqueue.c:2289
 worker_thread+0x665/0x1080 kernel/workqueue.c:2436
 kthread+0x2e4/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

Memory state around the buggy address:
 ffff8880261ddf80: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880261de000: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
>ffff8880261de080: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                      ^
 ffff8880261de100: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff8880261de180: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
==================================================================

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/08/22 20:35 upstream 1c23f9e627a7 26a13b38 .config strace log report syz C ci-upstream-kasan-gce-root KASAN: use-after-free Read in mgmt_pending_remove
2022/08/13 11:31 net-old 40b4ac880e21 8dfcaa3d .config strace log report syz C ci-upstream-net-this-kasan-gce KASAN: use-after-free Read in mgmt_pending_remove
2022/08/13 10:58 net-next-old 7ebfc85e2cd7 8dfcaa3d .config strace log report syz C ci-upstream-net-kasan-gce KASAN: use-after-free Read in mgmt_pending_remove
2022/08/21 06:06 net-old e82c649e851c 26a13b38 .config console log report info ci-upstream-net-this-kasan-gce KASAN: use-after-free Read in mgmt_pending_remove
2022/08/20 21:30 net-old e82c649e851c 26a13b38 .config console log report info ci-upstream-net-this-kasan-gce KASAN: use-after-free Read in mgmt_pending_remove
2022/08/27 21:11 net-next-old 53a406803ca5 07177916 .config console log report info ci-upstream-net-kasan-gce KASAN: use-after-free Read in mgmt_pending_remove
2022/08/13 10:38 net-next-old 7ebfc85e2cd7 8dfcaa3d .config console log report info ci-upstream-net-kasan-gce KASAN: use-after-free Read in mgmt_pending_remove
2022/09/06 07:29 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 85413d1e802e 9dcd38fc .config console log report info ci-upstream-gce-arm64 BUG: corrupted list in mgmt_pending_remove
2022/08/27 21:28 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci a41a877bc12d 07177916 .config console log report info ci-upstream-gce-arm64 BUG: corrupted list in mgmt_pending_remove
* Struck through repros no longer work on HEAD.