Kernel bug: KASAN: slab-use-after-free Read in cmp_bss
Subsystem: wireless
Status: fixed

Crash report:
==================================================================
BUG: KASAN: slab-use-after-free in cmp_bss+0xd4d/0xe80 net/wireless/scan.c:1504
Read of size 4 at addr ffff8880597b3918 by task kworker/u4:1/13

CPU: 0 UID: 0 PID: 13 Comm: kworker/u4:1 Not tainted syzkaller #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: events_unbound cfg80211_wiphy_work
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
 cmp_bss+0xd4d/0xe80 net/wireless/scan.c:1504
 rb_find_bss net/wireless/scan.c:1693 [inline]
 __cfg80211_bss_update+0xdb/0x2120 net/wireless/scan.c:1980
 cfg80211_inform_single_bss_data+0xba9/0x1ac0 net/wireless/scan.c:2375
 cfg80211_inform_bss_data+0x1fb/0x3b30 net/wireless/scan.c:3234
 cfg80211_inform_bss_frame_data+0x3d7/0x730 net/wireless/scan.c:3325
 ieee80211_bss_info_update+0x746/0x9e0 net/mac80211/scan.c:226
 ieee80211_rx_bss_info+0x176/0x280 net/mac80211/mlme.c:6564
 ieee80211_rx_mgmt_probe_resp net/mac80211/mlme.c:6607 [inline]
 ieee80211_sta_rx_queued_mgmt+0x1294/0x4470 net/mac80211/mlme.c:8089
 ieee80211_iface_process_skb net/mac80211/iface.c:1696 [inline]
 ieee80211_iface_work+0x652/0x12d0 net/mac80211/iface.c:1753
 cfg80211_wiphy_work+0x2bb/0x470 net/wireless/core.c:435
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 3046:
 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:388 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:405
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4365 [inline]
 __kmalloc_noprof+0x27a/0x4f0 mm/slub.c:4377
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 cfg80211_inform_single_bss_data+0x905/0x1ac0 net/wireless/scan.c:2351
 cfg80211_inform_bss_data+0x1fb/0x3b30 net/wireless/scan.c:3234
 cfg80211_inform_bss_frame_data+0x3d7/0x730 net/wireless/scan.c:3325
 ieee80211_bss_info_update+0x746/0x9e0 net/mac80211/scan.c:226
 ieee80211_rx_bss_info+0x176/0x280 net/mac80211/mlme.c:6564
 ieee80211_rx_mgmt_beacon+0x197d/0x2cd0 net/mac80211/mlme.c:7513
 ieee80211_sta_rx_queued_mgmt+0x4ed/0x4470 net/mac80211/mlme.c:8085
 ieee80211_iface_process_skb net/mac80211/iface.c:1696 [inline]
 ieee80211_iface_work+0x652/0x12d0 net/mac80211/iface.c:1753
 cfg80211_wiphy_work+0x2bb/0x470 net/wireless/core.c:435
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 3046:
 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:243 [inline]
 __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2417 [inline]
 slab_free_freelist_hook mm/slub.c:2446 [inline]
 slab_free_bulk mm/slub.c:4704 [inline]
 kmem_cache_free_bulk+0x2d1/0x520 mm/slub.c:5283
 kfree_bulk include/linux/slab.h:794 [inline]
 kvfree_rcu_bulk+0xe5/0x1f0 mm/slab_common.c:1516
 kvfree_rcu_drain_ready mm/slab_common.c:1699 [inline]
 kfree_rcu_monitor+0x211/0x2a0 mm/slab_common.c:1772
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47
 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548
 kvfree_call_rcu+0xbb/0x410 mm/slab_common.c:1962
 cfg80211_update_known_bss+0x454/0x1330 net/wireless/scan.c:1919
 cfg80211_update_assoc_bss_entry+0x4ba/0x6a0 net/wireless/scan.c:3454
 cfg80211_ch_switch_notify+0x3c1/0x780 net/wireless/nl80211.c:20398
 ieee80211_sta_process_chanswitch+0xad4/0x2870 net/mac80211/mlme.c:-1
 ieee80211_rx_mgmt_beacon+0x19c7/0x2cd0 net/mac80211/mlme.c:7515
 ieee80211_sta_rx_queued_mgmt+0x4ed/0x4470 net/mac80211/mlme.c:8085
 ieee80211_iface_process_skb net/mac80211/iface.c:1696 [inline]
 ieee80211_iface_work+0x652/0x12d0 net/mac80211/iface.c:1753
 cfg80211_wiphy_work+0x2bb/0x470 net/wireless/core.c:435
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff8880597b3900
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 24 bytes inside of
 freed 96-byte region [ffff8880597b3900, ffff8880597b3960)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880597b3880 pfn:0x597b3
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000000 ffff88801a441280 ffffea00013711c0 dead000000000002
raw: ffff8880597b3880 000000000020001e 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 9, tgid 9 (kworker/0:0), ts 132372320684, free_ts 130490331282
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851
 prep_new_page mm/page_alloc.c:1859 [inline]
 get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:2487 [inline]
 allocate_slab+0x8a/0x370 mm/slub.c:2655
 new_slab mm/slub.c:2709 [inline]
 ___slab_alloc+0xbeb/0x1410 mm/slub.c:3891
 __slab_alloc mm/slub.c:3981 [inline]
 __slab_alloc_node mm/slub.c:4056 [inline]
 slab_alloc_node mm/slub.c:4217 [inline]
 __kmalloc_cache_noprof+0x296/0x3d0 mm/slub.c:4391
 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:1849
 mld_send_cr net/ipv6/mcast.c:2159 [inline]
 mld_ifc_work+0x83e/0xd60 net/ipv6/mcast.c:2698
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
page last free pid 5385 tgid 5385 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895
 vfree+0x25a/0x400 mm/vmalloc.c:3434
 kcov_put kernel/kcov.c:439 [inline]
 kcov_close+0x28/0x50 kernel/kcov.c:535
 __fput+0x44c/0xa70 fs/file_table.c:468
 task_work_run+0x1d4/0x260 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x6b5/0x2300 kernel/exit.c:961
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
 get_signal+0x1286/0x1340 kernel/signal.c:3034
 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff8880597b3800: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff8880597b3880: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff8880597b3900: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                            ^
 ffff8880597b3980: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff8880597b3a00: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
==================================================================