KASAN: slab-use-after-free Read in l2cap_recv_acldata

Status: auto-obsoleted due to no activity on 2024/10/07 16:15
Subsystems: bluetooth
[Documentation on labels]
Reported-by: syzbot+165ba199a4fe7118b2de@syzkaller.appspotmail.com
First crash: 771d, last: 771d
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [bluetooth?] KASAN: slab-use-after-free Read in l2cap_recv_acldata 0 (1) 2024/07/03 22:24
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: slab-use-after-free Read in l2cap_recv_acldata (2) bluetooth 19 3 294d 333d 29/29 fixed on 2026/01/07 12:29
upstream BUG: sleeping function called from invalid context in hci_cmd_sync_submit bluetooth 19 syz, C done done 3400 889d 1132d 0/29 auto-obsoleted due to no activity on 2024/05/13 05:09

Sample crash report:
Bluetooth: Unexpected start frame (len 7)
==================================================================
BUG: KASAN: slab-use-after-free in l2cap_recv_reset net/bluetooth/l2cap_core.c:7469 [inline]
BUG: KASAN: slab-use-after-free in l2cap_recv_acldata+0x325/0x1550 net/bluetooth/l2cap_core.c:7493
Read of size 8 at addr ffff8880202c10c8 by task kworker/u9:5/5096

CPU: 1 PID: 5096 Comm: kworker/u9:5 Not tainted 6.10.0-rc5-syzkaller-00253-gde0a9f448633 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Workqueue: hci2 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
 l2cap_recv_reset net/bluetooth/l2cap_core.c:7469 [inline]
 l2cap_recv_acldata+0x325/0x1550 net/bluetooth/l2cap_core.c:7493
 hci_acldata_packet net/bluetooth/hci_core.c:3842 [inline]
 hci_rx_work+0x50f/0xca0 net/bluetooth/hci_core.c:4079
 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 5089:
 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_noprof+0x19c/0x2c0 mm/slub.c:4154
 kmalloc_noprof include/linux/slab.h:660 [inline]
 kzalloc_noprof include/linux/slab.h:778 [inline]
 l2cap_conn_add+0xa9/0x8e0 net/bluetooth/l2cap_core.c:6864
 l2cap_connect_cfm+0x136/0x1220 net/bluetooth/l2cap_core.c:7241
 hci_connect_cfm+0xa2/0x150 include/net/bluetooth/hci_core.h:1970
 le_conn_complete_evt+0xd3e/0x12e0 net/bluetooth/hci_event.c:5761
 hci_le_conn_complete_evt+0x18c/0x420 net/bluetooth/hci_event.c:5787
 hci_event_func net/bluetooth/hci_event.c:7414 [inline]
 hci_event_packet+0xa53/0x1540 net/bluetooth/hci_event.c:7469
 hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4074
 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 4477:
 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:4438 [inline]
 kfree+0x149/0x360 mm/slub.c:4559
 l2cap_connect_cfm+0x11f/0x1220 net/bluetooth/l2cap_core.c:7237
 hci_connect_cfm include/net/bluetooth/hci_core.h:1970 [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

Last potentially related work creation:
 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:541
 insert_work+0x3e/0x330 kernel/workqueue.c:2208
 __queue_work+0xaf2/0xee0 kernel/workqueue.c:2364
 queue_work_on+0x1c2/0x380 kernel/workqueue.c:2411
 queue_work include/linux/workqueue.h:621 [inline]
 l2cap_conn_ready net/bluetooth/l2cap_core.c:1640 [inline]
 l2cap_connect_cfm+0xec2/0x1220 net/bluetooth/l2cap_core.c:7282
 hci_connect_cfm+0xa2/0x150 include/net/bluetooth/hci_core.h:1970
 le_conn_complete_evt+0xd3e/0x12e0 net/bluetooth/hci_event.c:5761
 hci_le_conn_complete_evt+0x18c/0x420 net/bluetooth/hci_event.c:5787
 hci_event_func net/bluetooth/hci_event.c:7414 [inline]
 hci_event_packet+0xa53/0x1540 net/bluetooth/hci_event.c:7469
 hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4074
 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 ffff8880202c1000
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 200 bytes inside of
 freed 1024-byte region [ffff8880202c1000, ffff8880202c1400)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x202c0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffefff(slab)
raw: 00fff00000000040 ffff888015041dc0 ffffea0001de3000 dead000000000002
raw: 0000000000000000 0000000000100010 00000001ffffefff 0000000000000000
head: 00fff00000000040 ffff888015041dc0 ffffea0001de3000 dead000000000002
head: 0000000000000000 0000000000100010 00000001ffffefff 0000000000000000
head: 00fff00000000003 ffffea000080b001 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 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 0x152820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 2480, tgid 2480 (kworker/u8:7), ts 97857353301, free_ts 95178990419
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1473
 prep_new_page mm/page_alloc.c:1481 [inline]
 get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3425
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4683
 __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:3990 [inline]
 __do_kmalloc_node mm/slub.c:4122 [inline]
 __kmalloc_noprof+0x257/0x400 mm/slub.c:4136
 kmalloc_noprof include/linux/slab.h:664 [inline]
 kzalloc_noprof include/linux/slab.h:778 [inline]
 ieee802_11_parse_elems_full+0xd5/0x2870 net/mac80211/parse.c:880
 ieee802_11_parse_elems_crc net/mac80211/ieee80211_i.h:2332 [inline]
 ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2339 [inline]
 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1574 [inline]
 ieee80211_ibss_rx_queued_mgmt+0x4c8/0x2d70 net/mac80211/ibss.c:1605
 ieee80211_iface_process_skb net/mac80211/iface.c:1603 [inline]
 ieee80211_iface_work+0x8a3/0xf10 net/mac80211/iface.c:1657
 cfg80211_wiphy_work+0x221/0x260 net/wireless/core.c:437
 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
page last free pid 9 tgid 9 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1093 [inline]
 free_unref_page+0xd19/0xea0 mm/page_alloc.c:2588
 __slab_free+0x31b/0x3d0 mm/slub.c:4349
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9e/0x140 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:3940 [inline]
 slab_alloc_node mm/slub.c:4002 [inline]
 kmalloc_trace_noprof+0x132/0x2c0 mm/slub.c:4149
 kmalloc_noprof include/linux/slab.h:660 [inline]
 kzalloc_noprof include/linux/slab.h:778 [inline]
 nsim_fib6_rt_create drivers/net/netdevsim/fib.c:547 [inline]
 nsim_fib6_rt_insert drivers/net/netdevsim/fib.c:752 [inline]
 nsim_fib6_event drivers/net/netdevsim/fib.c:856 [inline]
 nsim_fib_event drivers/net/netdevsim/fib.c:889 [inline]
 nsim_fib_event_work+0x19c2/0x4130 drivers/net/netdevsim/fib.c:1492
 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

Memory state around the buggy address:
 ffff8880202c0f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880202c1000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880202c1080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff8880202c1100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880202c1180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/29 16:14 upstream de0a9f448633 757f06b1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: slab-use-after-free Read in l2cap_recv_acldata
* Struck through repros no longer work on HEAD.