syzbot


KASAN: slab-use-after-free Read in l2cap_send_cmd

Status: upstream: reported on 2024/02/26 09:32
Subsystems: bluetooth
[Documentation on labels]
Reported-by: syzbot+31c2f641b850a348a734@syzkaller.appspotmail.com
First crash: 61d, last: 4d18h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [bluetooth?] KASAN: slab-use-after-free Read in l2cap_send_cmd 0 (1) 2024/02/26 09:32

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in l2cap_build_cmd net/bluetooth/l2cap_core.c:3113 [inline]
BUG: KASAN: slab-use-after-free in l2cap_send_cmd+0x187/0x8d0 net/bluetooth/l2cap_core.c:958
Read of size 8 at addr ffff888011388800 by task kworker/u5:0/15190

CPU: 1 PID: 15190 Comm: kworker/u5:0 Not tainted 6.8.0-rc6-syzkaller-00238-g5ad3cb0ed525 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Workqueue: hci9 hci_rx_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x167/0x540 mm/kasan/report.c:488
 kasan_report+0x142/0x180 mm/kasan/report.c:601
 l2cap_build_cmd net/bluetooth/l2cap_core.c:3113 [inline]
 l2cap_send_cmd+0x187/0x8d0 net/bluetooth/l2cap_core.c:958
 l2cap_le_sig_channel net/bluetooth/l2cap_core.c:6486 [inline]
 l2cap_recv_frame+0x546c/0x8c10 net/bluetooth/l2cap_core.c:7828
 hci_acldata_packet net/bluetooth/hci_core.c:3876 [inline]
 hci_rx_work+0x50f/0xca0 net/bluetooth/hci_core.c:4111
 process_one_work kernel/workqueue.c:2633 [inline]
 process_scheduled_works+0x913/0x1420 kernel/workqueue.c:2706
 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2787
 kthread+0x2ef/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:243
 </TASK>

Allocated by task 11287:
 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+0x1d6/0x360 mm/slub.c:4012
 kmalloc include/linux/slab.h:590 [inline]
 kzalloc include/linux/slab.h:711 [inline]
 l2cap_conn_add+0xb6/0xc10 net/bluetooth/l2cap_core.c:7861
 l2cap_connect_cfm+0x138/0x1290 net/bluetooth/l2cap_core.c:8258
 hci_connect_cfm+0xa2/0x150 include/net/bluetooth/hci_core.h:1986
 le_conn_complete_evt+0xd10/0x1290 net/bluetooth/hci_event.c:6028
 hci_le_conn_complete_evt+0x18c/0x420 net/bluetooth/hci_event.c:6054
 hci_event_func net/bluetooth/hci_event.c:7686 [inline]
 hci_event_packet+0xa53/0x1540 net/bluetooth/hci_event.c:7741
 hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4106
 process_one_work kernel/workqueue.c:2633 [inline]
 process_scheduled_works+0x913/0x1420 kernel/workqueue.c:2706
 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2787
 kthread+0x2ef/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:243

Freed by task 11287:
 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:589
 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:2121 [inline]
 slab_free mm/slub.c:4299 [inline]
 kfree+0x14a/0x380 mm/slub.c:4409
 l2cap_connect_cfm+0x121/0x1290 net/bluetooth/l2cap_core.c:8254
 hci_connect_cfm include/net/bluetooth/hci_core.h:1986 [inline]
 hci_conn_failed+0x1f6/0x340 net/bluetooth/hci_conn.c:1289
 hci_abort_conn_sync+0x583/0xde0 net/bluetooth/hci_sync.c:5359
 hci_cmd_sync_work+0x22b/0x400 net/bluetooth/hci_sync.c:306
 process_one_work kernel/workqueue.c:2633 [inline]
 process_scheduled_works+0x913/0x1420 kernel/workqueue.c:2706
 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2787
 kthread+0x2ef/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:243

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:551
 insert_work+0x3e/0x330 kernel/workqueue.c:1653
 __queue_work+0xcdb/0x1000 kernel/workqueue.c:1806
 queue_work_on+0x14f/0x250 kernel/workqueue.c:1837
 queue_work include/linux/workqueue.h:548 [inline]
 l2cap_conn_ready net/bluetooth/l2cap_core.c:1779 [inline]
 l2cap_connect_cfm+0xf34/0x1290 net/bluetooth/l2cap_core.c:8299
 hci_connect_cfm+0xa2/0x150 include/net/bluetooth/hci_core.h:1986
 le_conn_complete_evt+0xd10/0x1290 net/bluetooth/hci_event.c:6028
 hci_le_conn_complete_evt+0x18c/0x420 net/bluetooth/hci_event.c:6054
 hci_event_func net/bluetooth/hci_event.c:7686 [inline]
 hci_event_packet+0xa53/0x1540 net/bluetooth/hci_event.c:7741
 hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4106
 process_one_work kernel/workqueue.c:2633 [inline]
 process_scheduled_works+0x913/0x1420 kernel/workqueue.c:2706
 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2787
 kthread+0x2ef/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:243

The buggy address belongs to the object at ffff888011388800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 0 bytes inside of
 freed 1024-byte region [ffff888011388800, ffff888011388c00)

The buggy address belongs to the physical page:
page:ffffea000044e200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11388
head:ffffea000044e200 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 ffff888014c41dc0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000100010 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 0x152820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 11, tgid 11 (kworker/u4:0), ts 1380683051229, free_ts 1379859253651
 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+0x255/0x680 mm/page_alloc.c:4567
 __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:2190
 allocate_slab mm/slub.c:2354 [inline]
 new_slab+0x84/0x2f0 mm/slub.c:2407
 ___slab_alloc+0xd17/0x13e0 mm/slub.c:3540
 __slab_alloc mm/slub.c:3625 [inline]
 __slab_alloc_node mm/slub.c:3678 [inline]
 slab_alloc_node mm/slub.c:3850 [inline]
 __do_kmalloc_node mm/slub.c:3980 [inline]
 __kmalloc+0x2e0/0x490 mm/slub.c:3994
 kmalloc include/linux/slab.h:594 [inline]
 kzalloc include/linux/slab.h:711 [inline]
 ieee802_11_parse_elems_full+0xe7/0x2470 net/mac80211/util.c:1628
 ieee802_11_parse_elems_crc net/mac80211/ieee80211_i.h:2291 [inline]
 ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2298 [inline]
 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1573 [inline]
 ieee80211_ibss_rx_queued_mgmt+0x4b7/0x2cd0 net/mac80211/ibss.c:1604
 ieee80211_iface_process_skb net/mac80211/iface.c:1589 [inline]
 ieee80211_iface_work+0x809/0xd90 net/mac80211/iface.c:1643
 cfg80211_wiphy_work+0x221/0x260 net/wireless/core.c:437
 process_one_work kernel/workqueue.c:2633 [inline]
 process_scheduled_works+0x913/0x1420 kernel/workqueue.c:2706
 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2787
 kthread+0x2ef/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:243
page last free pid 23489 tgid 23486 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+0x95d/0xa80 mm/page_alloc.c:2346
 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2486
 __slab_free+0x349/0x410 mm/slub.c:4211
 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:3813 [inline]
 slab_alloc_node mm/slub.c:3860 [inline]
 kmem_cache_alloc+0x16f/0x340 mm/slub.c:3867
 kmem_cache_zalloc include/linux/slab.h:701 [inline]
 jbd2_alloc_handle include/linux/jbd2.h:1591 [inline]
 new_handle fs/jbd2/transaction.c:476 [inline]
 jbd2__journal_start+0x14c/0x5d0 fs/jbd2/transaction.c:503
 __ext4_journal_start_sb+0x215/0x5b0 fs/ext4/ext4_jbd2.c:112
 __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline]
 ext4_dirty_inode+0x92/0x110 fs/ext4/inode.c:5939
 __mark_inode_dirty+0x309/0xdb0 fs/fs-writeback.c:2452
 generic_update_time fs/inode.c:1905 [inline]
 inode_update_time fs/inode.c:1918 [inline]
 touch_atime+0x42c/0x670 fs/inode.c:1990
 ext4_file_read_iter+0x585/0x680
 call_read_iter include/linux/fs.h:2081 [inline]
 copy_splice_read+0x661/0xb60 fs/splice.c:365
 do_splice_read fs/splice.c:984 [inline]
 splice_direct_to_actor+0x501/0xc80 fs/splice.c:1089
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0x28c/0x3e0 fs/splice.c:1233

Memory state around the buggy address:
 ffff888011388700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888011388780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888011388800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888011388880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888011388900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/03/02 14:01 upstream 5ad3cb0ed525 25905f5d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: slab-use-after-free Read in l2cap_send_cmd
2024/02/19 23:04 upstream b401b621758e 3af7dd65 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root KASAN: slab-use-after-free Read in l2cap_send_cmd
2024/04/06 18:20 upstream fe46a7dd189e ca620dd8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 KASAN: slab-use-after-free Read in l2cap_send_cmd
2024/04/16 17:39 linux-next 66e4190e92ce 0d592ce4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in l2cap_send_cmd
* Struck through repros no longer work on HEAD.