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BUG: KASAN: use-after-free in f2fs_available_free_memory+0xa98/0xb00 fs/f2fs/node.c:99
Read of size 4 at addr ffff8881069d6010 by task f2fs_discard-7:/26239

CPU: 0 PID: 26239 Comm: f2fs_discard-7: Tainted: G        W         5.10.85-syzkaller-00573-gafc997898ece #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118
 print_address_description+0x8d/0x3d0 mm/kasan/report.c:233
 __kasan_report+0x142/0x220 mm/kasan/report.c:419
 kasan_report+0x51/0x70 mm/kasan/report.c:436
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308
 f2fs_available_free_memory+0xa98/0xb00 fs/f2fs/node.c:99
 issue_discard_thread+0x2dd/0x1b00 fs/f2fs/segment.c:1761
 kthread+0x371/0x390 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Allocated by task 26222:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:428 [inline]
 ____kasan_kmalloc+0xdc/0x110 mm/kasan/common.c:507
 __kasan_kmalloc+0x9/0x10 mm/kasan/common.c:516
 kasan_kmalloc include/linux/kasan.h:269 [inline]
 kmem_cache_alloc_trace+0x210/0x3a0 mm/slub.c:2975
 kmalloc include/linux/slab.h:552 [inline]
 f2fs_kmalloc fs/f2fs/f2fs.h:3167 [inline]
 f2fs_kzalloc fs/f2fs/f2fs.h:3173 [inline]
 f2fs_build_node_manager+0x57/0x1390 fs/f2fs/node.c:3212
 f2fs_fill_super+0x6447/0x8f90 fs/f2fs/super.c:3992
 mount_bdev+0x25f/0x370 fs/super.c:1419
 f2fs_mount+0x34/0x40 fs/f2fs/super.c:4258
 legacy_get_tree+0xf0/0x190 fs/fs_context.c:592
 vfs_get_tree+0x89/0x270 fs/super.c:1549
 do_new_mount fs/namespace.c:2899 [inline]
 path_mount+0x1975/0x2ab0 fs/namespace.c:3229
 do_mount fs/namespace.c:3242 [inline]
 __do_sys_mount fs/namespace.c:3450 [inline]
 __se_sys_mount+0x2f7/0x3b0 fs/namespace.c:3427
 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3427
 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 26222:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4c/0x80 mm/kasan/common.c:46
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:357
 ____kasan_slab_free+0x133/0x170 mm/kasan/common.c:360
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:368
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:1596 [inline]
 slab_free_freelist_hook+0xcc/0x1a0 mm/slub.c:1622
 slab_free mm/slub.c:3204 [inline]
 kfree+0xd5/0x320 mm/slub.c:4192
 f2fs_destroy_node_manager+0xdfd/0xf60 fs/f2fs/node.c:3305
 f2fs_fill_super+0x7475/0x8f90 fs/f2fs/super.c:4203
 mount_bdev+0x25f/0x370 fs/super.c:1419
 f2fs_mount+0x34/0x40 fs/f2fs/super.c:4258
 legacy_get_tree+0xf0/0x190 fs/fs_context.c:592
 vfs_get_tree+0x89/0x270 fs/super.c:1549
 do_new_mount fs/namespace.c:2899 [inline]
 path_mount+0x1975/0x2ab0 fs/namespace.c:3229
 do_mount fs/namespace.c:3242 [inline]
 __do_sys_mount fs/namespace.c:3450 [inline]
 __se_sys_mount+0x2f7/0x3b0 fs/namespace.c:3427
 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3427
 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff8881069d6000
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 16 bytes inside of
 512-byte region [ffff8881069d6000, ffff8881069d6200)
The buggy address belongs to the page:
page:ffffea00041a7500 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1069d4
head:ffffea00041a7500 order:2 compound_mapcount:0 compound_pincount:0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 dead000000000100 dead000000000122 ffff888100043080
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 374, ts 88074405389, free_ts 88069434999
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2385 [inline]
 prep_new_page mm/page_alloc.c:2391 [inline]
 get_page_from_freelist+0xa74/0xa90 mm/page_alloc.c:4063
 __alloc_pages_nodemask+0x3c8/0x820 mm/page_alloc.c:5106
 alloc_slab_page mm/slub.c:1807 [inline]
 allocate_slab+0x6b/0x350 mm/slub.c:1809
 new_slab mm/slub.c:1870 [inline]
 new_slab_objects mm/slub.c:2629 [inline]
 ___slab_alloc+0x143/0x2f0 mm/slub.c:2792
 __slab_alloc mm/slub.c:2832 [inline]
 slab_alloc_node mm/slub.c:2914 [inline]
 slab_alloc mm/slub.c:2956 [inline]
 __kmalloc_track_caller+0x299/0x3b0 mm/slub.c:4535
 __kmalloc_reserve net/core/skbuff.c:143 [inline]
 __alloc_skb+0xb7/0x580 net/core/skbuff.c:211
 alloc_skb include/linux/skbuff.h:1101 [inline]
 nlmsg_new include/net/netlink.h:953 [inline]
 rtmsg_ifa+0x1f1/0x3b0 net/ipv4/devinet.c:1900
 __inet_insert_ifa+0x8b7/0xb20 net/ipv4/devinet.c:552
 inet_rtm_newaddr+0x8f7/0x16b0 net/ipv4/devinet.c:957
 rtnetlink_rcv_msg+0xbae/0xd70 net/core/rtnetlink.c:5567
 netlink_rcv_skb+0x200/0x470 net/netlink/af_netlink.c:2502
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5585
 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline]
 netlink_unicast+0x814/0x9f0 net/netlink/af_netlink.c:1337
 netlink_sendmsg+0xa20/0xe00 net/netlink/af_netlink.c:1927
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 __sys_sendto+0x541/0x700 net/socket.c:1982
 __do_sys_sendto net/socket.c:1994 [inline]
 __se_sys_sendto net/socket.c:1990 [inline]
 __x64_sys_sendto+0xe5/0x100 net/socket.c:1990
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1331 [inline]
 __free_pages_ok+0xbe7/0xc20 mm/page_alloc.c:1611
 free_the_page mm/page_alloc.c:5167 [inline]
 __free_pages+0x2d6/0x4a0 mm/page_alloc.c:5173
 __free_slab+0xdf/0x1a0 mm/slub.c:1895
 free_slab mm/slub.c:1910 [inline]
 discard_slab mm/slub.c:1916 [inline]
 unfreeze_partials+0x17d/0x1b0 mm/slub.c:2410
 put_cpu_partial+0xc8/0x190 mm/slub.c:2446
 __slab_free+0x2eb/0x4e0 mm/slub.c:3096
 do_slab_free mm/slub.c:3192 [inline]
 ___cache_free+0x131/0x150 mm/slub.c:3211
 qlink_free+0x38/0x40 mm/kasan/quarantine.c:146
 qlist_free_all mm/kasan/quarantine.c:165 [inline]
 kasan_quarantine_reduce+0x178/0x1d0 mm/kasan/quarantine.c:272
 __kasan_slab_alloc+0x2f/0xe0 mm/kasan/common.c:438
 kasan_slab_alloc include/linux/kasan.h:259 [inline]
 slab_post_alloc_hook mm/slab.h:583 [inline]
 slab_alloc_node mm/slub.c:2948 [inline]
 slab_alloc mm/slub.c:2956 [inline]
 __kmalloc+0x1c7/0x3d0 mm/slub.c:4030
 kmalloc include/linux/slab.h:557 [inline]
 kzalloc include/linux/slab.h:664 [inline]
 fib6_info_alloc+0x33/0xe0 net/ipv6/ip6_fib.c:154
 ip6_route_info_create+0x588/0x1aa0 net/ipv6/route.c:3644
 ip6_route_add+0x27/0x130 net/ipv6/route.c:3738
 addrconf_add_mroute net/ipv6/addrconf.c:2500 [inline]
 addrconf_add_dev+0x419/0x5f0 net/ipv6/addrconf.c:2518
 addrconf_dev_config+0x237/0x570 net/ipv6/addrconf.c:3376

Memory state around the buggy address:
 ffff8881069d5f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881069d5f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8881069d6000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff8881069d6080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881069d6100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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