================================================================== BUG: KASAN: use-after-free in f2fs_available_free_memory+0xa98/0xb00 fs/f2fs/node.c:99 Read of size 4 at addr ffff88810e9a7c10 by task f2fs_discard-7:/8436 CPU: 0 PID: 8436 Comm: f2fs_discard-7: Not tainted 5.10.89-syzkaller-00788-g9b28b48fb343 #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 8420: 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 8420: 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 ffff88810e9a7c00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 16 bytes inside of 512-byte region [ffff88810e9a7c00, ffff88810e9a7e00) The buggy address belongs to the page: page:ffffea00043a6900 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10e9a4 head:ffffea00043a6900 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x8000000000010200(slab|head) raw: 8000000000010200 ffffea0004341400 0000000300000003 ffff888100043080 raw: 0000000000000000 0000000080100010 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 0x152a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 74, ts 331215856380, free_ts 331138087770 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+0x2af/0x3d0 mm/slub.c:4030 kmalloc include/linux/slab.h:557 [inline] kzalloc include/linux/slab.h:664 [inline] neigh_alloc net/core/neighbour.c:406 [inline] ___neigh_create+0x608/0x1a50 net/core/neighbour.c:590 __neigh_create+0x32/0x40 net/core/neighbour.c:678 ip6_finish_output2+0xa11/0x1930 net/ipv6/ip6_output.c:142 __ip6_finish_output+0x610/0x7b0 net/ipv6/ip6_output.c:210 ip6_finish_output+0x3f/0x1e0 net/ipv6/ip6_output.c:220 NF_HOOK_COND include/linux/netfilter.h:293 [inline] ip6_output+0x211/0x4c0 net/ipv6/ip6_output.c:243 dst_output include/net/dst.h:443 [inline] NF_HOOK include/linux/netfilter.h:304 [inline] ndisc_send_skb+0x6fe/0xc10 net/ipv6/ndisc.c:508 ndisc_send_rs+0x522/0x690 net/ipv6/ndisc.c:702 addrconf_dad_completed+0x8ee/0xdc0 net/ipv6/addrconf.c:4224 addrconf_dad_work+0xe4b/0x1d40 net/ipv6/addrconf.c:3989 process_one_work+0x6b4/0xfb0 kernel/workqueue.c:2289 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] kmem_cache_alloc_trace+0x1a5/0x3a0 mm/slub.c:2973 kmalloc include/linux/slab.h:552 [inline] __kthread_create_on_node+0x11f/0x410 kernel/kthread.c:358 kthread_create_on_node+0xda/0x120 kernel/kthread.c:447 loop_prepare_queue drivers/block/loop.c:931 [inline] loop_configure+0x702/0x15b0 drivers/block/loop.c:1124 lo_ioctl+0x821/0x2380 drivers/block/loop.c:1690 __blkdev_driver_ioctl block/ioctl.c:237 [inline] blkdev_ioctl+0x2c3/0x5f0 block/ioctl.c:632 Memory state around the buggy address: ffff88810e9a7b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88810e9a7b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88810e9a7c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88810e9a7c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88810e9a7d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================