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BUG: KASAN: use-after-free in fb_mode_is_equal+0x284/0x2f0 drivers/video/fbdev/core/modedb.c:924
Read of size 4 at addr ffff88803cceb51c by task syz-executor.3/10936

CPU: 0 PID: 10936 Comm: syz-executor.3 Not tainted 5.13.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x141/0x1d7 lib/dump_stack.c:120
 print_address_description.constprop.0.cold+0x5b/0x2c6 mm/kasan/report.c:233
 __kasan_report mm/kasan/report.c:419 [inline]
 kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:436
 fb_mode_is_equal+0x284/0x2f0 drivers/video/fbdev/core/modedb.c:924
 fbcon_mode_deleted+0x13d/0x1d0 drivers/video/fbdev/core/fbcon.c:2718
 fb_set_var+0xae1/0xda0 drivers/video/fbdev/core/fbmem.c:975
 do_fb_ioctl+0x2f9/0x690 drivers/video/fbdev/core/fbmem.c:1108
 fb_ioctl+0xe7/0x150 drivers/video/fbdev/core/fbmem.c:1185
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:1069 [inline]
 __se_sys_ioctl fs/ioctl.c:1055 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2184175188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 00000000200002c0 RSI: 0000000000004601 RDI: 0000000000000003
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffc224d5b6f R14: 00007f2184175300 R15: 0000000000022000

Allocated by task 31612:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:428 [inline]
 ____kasan_kmalloc mm/kasan/common.c:507 [inline]
 ____kasan_kmalloc mm/kasan/common.c:466 [inline]
 __kasan_kmalloc+0x98/0xc0 mm/kasan/common.c:516
 kasan_kmalloc include/linux/kasan.h:246 [inline]
 kmem_cache_alloc_trace+0x1fa/0x480 mm/slab.c:3575
 kmalloc include/linux/slab.h:556 [inline]
 fb_add_videomode drivers/video/fbdev/core/modedb.c:1073 [inline]
 fb_add_videomode+0x2fb/0x610 drivers/video/fbdev/core/modedb.c:1057
 fb_set_var+0x631/0xda0 drivers/video/fbdev/core/fbmem.c:1049
 do_fb_ioctl+0x2f9/0x690 drivers/video/fbdev/core/fbmem.c:1108
 fb_ioctl+0xe7/0x150 drivers/video/fbdev/core/fbmem.c:1185
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:1069 [inline]
 __se_sys_ioctl fs/ioctl.c:1055 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 10922:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357
 ____kasan_slab_free mm/kasan/common.c:360 [inline]
 ____kasan_slab_free mm/kasan/common.c:325 [inline]
 __kasan_slab_free+0xcd/0x100 mm/kasan/common.c:368
 kasan_slab_free include/linux/kasan.h:212 [inline]
 __cache_free mm/slab.c:3445 [inline]
 kfree+0x106/0x2c0 mm/slab.c:3803
 fb_delete_videomode+0x3d2/0x570 drivers/video/fbdev/core/modedb.c:1104
 fb_set_var+0xaf1/0xda0 drivers/video/fbdev/core/fbmem.c:978
 do_fb_ioctl+0x2f9/0x690 drivers/video/fbdev/core/fbmem.c:1108
 fb_ioctl+0xe7/0x150 drivers/video/fbdev/core/fbmem.c:1185
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:1069 [inline]
 __se_sys_ioctl fs/ioctl.c:1055 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Last potentially related work creation:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_record_aux_stack+0xa4/0xd0 mm/kasan/generic.c:345
 kvfree_call_rcu+0x74/0x8c0 kernel/rcu/tree.c:3597
 cfg80211_update_known_bss+0x833/0xa60 net/wireless/scan.c:1651
 cfg80211_bss_update+0xef/0x1e00 net/wireless/scan.c:1698
 cfg80211_inform_single_bss_frame_data+0x6e2/0xee0 net/wireless/scan.c:2404
 cfg80211_inform_bss_frame_data+0xa7/0xb10 net/wireless/scan.c:2437
 ieee80211_bss_info_update+0x3ce/0xb20 net/mac80211/scan.c:190
 ieee80211_rx_bss_info net/mac80211/ibss.c:1126 [inline]
 ieee80211_rx_mgmt_probe_beacon+0xccd/0x16b0 net/mac80211/ibss.c:1615
 ieee80211_ibss_rx_queued_mgmt+0xe43/0x1870 net/mac80211/ibss.c:1642
 ieee80211_iface_work+0x761/0x9e0 net/mac80211/iface.c:1437
 process_one_work+0x98d/0x1600 kernel/workqueue.c:2276
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2422
 kthread+0x3b1/0x4a0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Second to last potentially related work creation:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_record_aux_stack+0xa4/0xd0 mm/kasan/generic.c:345
 kvfree_call_rcu+0x74/0x8c0 kernel/rcu/tree.c:3597
 cfg80211_update_known_bss+0x833/0xa60 net/wireless/scan.c:1651
 cfg80211_bss_update+0xef/0x1e00 net/wireless/scan.c:1698
 cfg80211_inform_single_bss_frame_data+0x6e2/0xee0 net/wireless/scan.c:2404
 cfg80211_inform_bss_frame_data+0xa7/0xb10 net/wireless/scan.c:2437
 ieee80211_bss_info_update+0x3ce/0xb20 net/mac80211/scan.c:190
 ieee80211_rx_bss_info net/mac80211/ibss.c:1126 [inline]
 ieee80211_rx_mgmt_probe_beacon+0xccd/0x16b0 net/mac80211/ibss.c:1615
 ieee80211_ibss_rx_queued_mgmt+0xe43/0x1870 net/mac80211/ibss.c:1642
 ieee80211_iface_work+0x761/0x9e0 net/mac80211/iface.c:1437
 process_one_work+0x98d/0x1600 kernel/workqueue.c:2276
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2422
 kthread+0x3b1/0x4a0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

The buggy address belongs to the object at ffff88803cceb500
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 28 bytes inside of
 96-byte region [ffff88803cceb500, ffff88803cceb560)
The buggy address belongs to the page:
page:ffffea0000f33ac0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88803cceb700 pfn:0x3cceb
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea0000f10b08 ffffea000091b308 ffff888011040300
raw: ffff88803cceb700 ffff88803cceb000 000000010000001f 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 0x242220(__GFP_HIGH|__GFP_ATOMIC|__GFP_NOWARN|__GFP_COMP|__GFP_THISNODE), pid 8452, ts 95407952369, free_ts 95398846926
 prep_new_page mm/page_alloc.c:2358 [inline]
 get_page_from_freelist+0x1033/0x2b60 mm/page_alloc.c:3994
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5200
 __alloc_pages_node include/linux/gfp.h:549 [inline]
 kmem_getpages mm/slab.c:1377 [inline]
 cache_grow_begin+0x75/0x460 mm/slab.c:2593
 cache_alloc_refill+0x27f/0x380 mm/slab.c:2965
 ____cache_alloc mm/slab.c:3048 [inline]
 ____cache_alloc mm/slab.c:3031 [inline]
 __do_cache_alloc mm/slab.c:3275 [inline]
 slab_alloc mm/slab.c:3316 [inline]
 __do_kmalloc mm/slab.c:3700 [inline]
 __kmalloc+0x3eb/0x4d0 mm/slab.c:3711
 kmalloc include/linux/slab.h:561 [inline]
 switchdev_deferred_enqueue+0x27/0x270 net/switchdev/switchdev.c:87
 switchdev_port_attr_set_defer net/switchdev/switchdev.c:153 [inline]
 switchdev_port_attr_set+0xaf/0x110 net/switchdev/switchdev.c:172
 br_mc_disabled_update net/bridge/br_multicast.c:1606 [inline]
 br_multicast_add_port+0x1f8/0x3f0 net/bridge/br_multicast.c:1624
 new_nbp net/bridge/br_if.c:435 [inline]
 br_add_if+0x730/0x1c70 net/bridge/br_if.c:611
 do_set_master+0x1c8/0x220 net/core/rtnetlink.c:2520
 do_setlink+0x990/0x3af0 net/core/rtnetlink.c:2724
 __rtnl_newlink+0xdcf/0x1710 net/core/rtnetlink.c:3385
 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3500
 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5564
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1298 [inline]
 free_pcp_prepare+0x223/0x300 mm/page_alloc.c:1342
 free_unref_page_prepare mm/page_alloc.c:3250 [inline]
 free_unref_page+0x12/0x1d0 mm/page_alloc.c:3298
 __vunmap+0x783/0xb60 mm/vmalloc.c:2566
 free_work+0x58/0x70 mm/vmalloc.c:80
 process_one_work+0x98d/0x1600 kernel/workqueue.c:2276
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2422
 kthread+0x3b1/0x4a0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Memory state around the buggy address:
 ffff88803cceb400: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff88803cceb480: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
>ffff88803cceb500: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                            ^
 ffff88803cceb580: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff88803cceb600: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
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