================================================================== BUG: KASAN: use-after-free in F2FS_SB fs/f2fs/f2fs.h:1987 [inline] BUG: KASAN: use-after-free in F2FS_I_SB fs/f2fs/f2fs.h:1992 [inline] BUG: KASAN: use-after-free in F2FS_M_SB fs/f2fs/f2fs.h:1997 [inline] BUG: KASAN: use-after-free in F2FS_P_SB fs/f2fs/f2fs.h:2002 [inline] BUG: KASAN: use-after-free in f2fs_release_page+0x301/0x7d0 fs/f2fs/data.c:3615 Read of size 8 at addr ffff888106dac3c8 by task syz.5.4608/19340 CPU: 1 PID: 19340 Comm: syz.5.4608 Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x169/0x1d8 lib/dump_stack.c:118 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0xe2/0x130 mm/kasan/report.c:452 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309 F2FS_SB fs/f2fs/f2fs.h:1987 [inline] F2FS_I_SB fs/f2fs/f2fs.h:1992 [inline] F2FS_M_SB fs/f2fs/f2fs.h:1997 [inline] F2FS_P_SB fs/f2fs/f2fs.h:2002 [inline] f2fs_release_page+0x301/0x7d0 fs/f2fs/data.c:3615 try_to_release_page+0x18d/0x1e0 mm/filemap.c:3705 shrink_page_list+0x16b5/0x4120 mm/vmscan.c:1467 shrink_inactive_list+0x4f4/0xe80 mm/vmscan.c:2075 shrink_list mm/vmscan.c:2294 [inline] shrink_lruvec+0x2246/0x2770 mm/vmscan.c:5473 shrink_node_memcgs mm/vmscan.c:5660 [inline] shrink_node+0xf0c/0x2690 mm/vmscan.c:5690 shrink_zones mm/vmscan.c:5896 [inline] do_try_to_free_pages+0x5db/0x1560 mm/vmscan.c:5954 try_to_free_mem_cgroup_pages+0x233/0x5b0 mm/vmscan.c:6272 try_charge+0x42b/0x14e0 mm/memcontrol.c:2745 __mem_cgroup_charge+0x14c/0x6d0 mm/memcontrol.c:6871 mem_cgroup_charge include/linux/memcontrol.h:458 [inline] __add_to_page_cache_locked+0x1e7/0x980 mm/filemap.c:854 add_to_page_cache_lru+0xa7/0x210 mm/filemap.c:948 pagecache_get_page+0x704/0x930 mm/filemap.c:1859 grab_cache_page_write_begin+0x59/0xb0 mm/filemap.c:3459 simple_write_begin+0x36/0x290 fs/libfs.c:531 generic_perform_write+0x2be/0x510 mm/filemap.c:3509 __generic_file_write_iter+0x24b/0x480 mm/filemap.c:3638 generic_file_write_iter+0xa9/0x1d0 mm/filemap.c:3670 __kernel_write+0x55a/0x910 fs/read_write.c:550 dump_emit+0x240/0x360 fs/coredump.c:855 dump_user_range+0x6a/0x1a0 fs/coredump.c:908 elf_core_dump+0x278a/0x2bc0 fs/binfmt_elf.c:2290 do_coredump+0x1ac9/0x27f0 fs/coredump.c:817 get_signal+0xf23/0x12e0 kernel/signal.c:2779 arch_do_signal_or_restart+0xbf/0x10f0 arch/x86/kernel/signal.c:805 handle_signal_work kernel/entry/common.c:145 [inline] exit_to_user_mode_loop+0xa2/0xe0 kernel/entry/common.c:169 exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:199 irqentry_exit_to_user_mode+0x9/0x10 kernel/entry/common.c:287 irqentry_exit+0x12/0x60 kernel/entry/common.c:375 exc_page_fault+0x67/0xc0 arch/x86/mm/fault.c:1487 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:571 RIP: 0033:0x7f28dbc46987 Code: 88 15 72 5d ec 00 88 05 6f 5d ec 00 c3 50 48 8d 35 19 26 1c 00 48 8d 3d 1f 26 1c 00 31 c0 e8 20 f7 ff ff 53 89 fb 48 83 ec 10 <64> 8b 04 25 94 ff ff ff 85 c0 74 2a 89 fe 31 c0 bf 3c 00 00 00 e8 RSP: 002b:00007f28da7cf120 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007f28dbd85fc9 RDX: 00007f28da7cf140 RSI: 00007f28da7cf270 RDI: 000000000000000b RBP: 00007f28dbe08f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f28dbfdd038 R14: 00007f28dbfdcfa0 R15: 00007fff5a9c61e8 Allocated by task 15236: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:430 [inline] ____kasan_kmalloc mm/kasan/common.c:509 [inline] __kasan_kmalloc+0xda/0x110 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] kmem_cache_alloc_trace+0x184/0x2e0 mm/slub.c:2979 kmalloc include/linux/slab.h:552 [inline] kzalloc include/linux/slab.h:664 [inline] alloc_super+0x5e/0x7a0 fs/super.c:203 sget+0x1e4/0x4c0 fs/super.c:627 mount_bdev+0xf6/0x3a0 fs/super.c:1415 f2fs_mount+0x34/0x40 fs/f2fs/super.c:4595 legacy_get_tree+0xed/0x190 fs/fs_context.c:593 vfs_get_tree+0x89/0x260 fs/super.c:1572 do_new_mount+0x25a/0xa20 fs/namespace.c:2997 path_mount+0x572/0xc80 fs/namespace.c:3327 do_mount fs/namespace.c:3340 [inline] __do_sys_mount fs/namespace.c:3548 [inline] __se_sys_mount+0x318/0x380 fs/namespace.c:3525 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3525 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 insert_work+0x52/0x310 kernel/workqueue.c:1352 __queue_work+0x923/0xca0 kernel/workqueue.c:1518 queue_work_on+0xd5/0x130 kernel/workqueue.c:1545 queue_work include/linux/workqueue.h:515 [inline] schedule_work include/linux/workqueue.h:576 [inline] destroy_super_rcu+0xd1/0xe0 fs/super.c:172 rcu_do_batch+0x4df/0xa80 kernel/rcu/tree.c:2494 rcu_core+0x55f/0xd60 kernel/rcu/tree.c:2735 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2748 __do_softirq+0x255/0x563 kernel/softirq.c:309 Second to last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 __call_rcu kernel/rcu/tree.c:2980 [inline] call_rcu+0x10e/0x1050 kernel/rcu/tree.c:3054 __put_super+0x254/0x2b0 fs/super.c:299 put_super fs/super.c:313 [inline] deactivate_locked_super+0xd4/0x100 fs/super.c:346 deactivate_super+0xaf/0xe0 fs/super.c:366 cleanup_mnt+0x446/0x500 fs/namespace.c:1114 __cleanup_mnt+0x19/0x20 fs/namespace.c:1121 task_work_run+0x127/0x190 kernel/task_work.c:189 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:172 exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x1d/0x40 kernel/entry/common.c:274 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff888106dac000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 968 bytes inside of 2048-byte region [ffff888106dac000, ffff888106dac800) The buggy address belongs to the page: page:ffffea00041b6a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888106dac000 pfn:0x106da8 head:ffffea00041b6a00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 ffffea00049e5c08 ffffea0004c48208 ffff888100042d80 raw: ffff888106dac000 0000000000080003 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 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 279, ts 25303343248, free_ts 25296014531 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x179/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x2235/0x23d0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x268/0x5f0 mm/page_alloc.c:5370 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1813 [inline] new_slab+0x84/0x3f0 mm/slub.c:1874 new_slab_objects mm/slub.c:2632 [inline] ___slab_alloc+0x2a6/0x450 mm/slub.c:2796 __slab_alloc+0x63/0xa0 mm/slub.c:2836 slab_alloc_node mm/slub.c:2918 [inline] slab_alloc mm/slub.c:2960 [inline] __kmalloc_track_caller+0x1ef/0x320 mm/slub.c:4541 __kmalloc_reserve net/core/skbuff.c:144 [inline] pskb_expand_head+0x123/0x1110 net/core/skbuff.c:1653 netlink_trim+0x193/0x230 net/netlink/af_netlink.c:1295 netlink_broadcast_filtered+0x78/0x1270 net/netlink/af_netlink.c:1507 netlink_broadcast net/netlink/af_netlink.c:1552 [inline] nlmsg_multicast include/net/netlink.h:1033 [inline] nlmsg_notify+0xed/0x1b0 net/netlink/af_netlink.c:2546 rtnl_notify net/core/rtnetlink.c:737 [inline] rtmsg_ifinfo_send net/core/rtnetlink.c:3868 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:3883 [inline] rtmsg_ifinfo+0xea/0x130 net/core/rtnetlink.c:3889 register_netdevice+0x1134/0x13c0 net/core/dev.c:10101 __ip_tunnel_create+0x2bf/0x380 net/ipv4/ip_tunnel.c:267 ip_tunnel_init_net+0x290/0x740 net/ipv4/ip_tunnel.c:1083 ipgre_tap_init_net+0x29/0x30 net/ipv4/ip_gre.c:1701 page last free stack trace: reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1349 [inline] __free_pages_ok+0x7fc/0x820 mm/page_alloc.c:1629 free_the_page mm/page_alloc.c:5431 [inline] __free_pages+0xdd/0x380 mm/page_alloc.c:5440 __free_slab+0xcf/0x190 mm/slub.c:1899 free_slab mm/slub.c:1914 [inline] discard_slab mm/slub.c:1920 [inline] unfreeze_partials+0x15f/0x190 mm/slub.c:2415 put_cpu_partial+0xc1/0x180 mm/slub.c:2451 __slab_free+0x2c9/0x3a0 mm/slub.c:3100 do_slab_free mm/slub.c:3196 [inline] ___cache_free+0x111/0x130 mm/slub.c:3215 qlink_free+0x50/0x90 mm/kasan/quarantine.c:157 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x14a/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xf0 mm/kasan/common.c:440 kasan_slab_alloc include/linux/kasan.h:244 [inline] slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:580 slab_alloc_node mm/slub.c:2952 [inline] slab_alloc mm/slub.c:2960 [inline] kmem_cache_alloc_trace+0x160/0x2e0 mm/slub.c:2977 kmalloc include/linux/slab.h:552 [inline] kzalloc include/linux/slab.h:664 [inline] inetdev_init+0x84/0x480 net/ipv4/devinet.c:259 inetdev_event+0x1f8/0x1030 net/ipv4/devinet.c:1544 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0x90/0x100 kernel/notifier.c:410 Memory state around the buggy address: ffff888106dac280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888106dac300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888106dac380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888106dac400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888106dac480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== general protection fault, probably for non-canonical address 0xdffffc00000000eb: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000758-0x000000000000075f] CPU: 0 PID: 19340 Comm: syz.5.4608 Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:f2fs_release_page+0x312/0x7d0 fs/f2fs/data.c:3615 Code: 4d 03 27 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 e7 e8 3f eb 97 ff 41 bf 58 07 00 00 4d 03 3c 24 4c 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 1d 04 00 00 45 8b 3f 44 89 fe 81 e6 00 RSP: 0018:ffffc90000c05e50 EFLAGS: 00010206 RAX: 00000000000000eb RBX: ffffea0004f61540 RCX: 0000000000000282 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00000000ffffffff RBP: ffffc90000c05e88 R08: 0000000000000004 R09: 0000000000000003 R10: fffffbfff0d8ee48 R11: 1ffffffff0d8ee48 R12: ffff888106dac3c8 R13: dffffc0000000000 R14: 1ffffd40009ec2a9 R15: 0000000000000758 FS: 0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2eb16ff8 CR3: 000000011284e000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: try_to_release_page+0x18d/0x1e0 mm/filemap.c:3705 shrink_page_list+0x16b5/0x4120 mm/vmscan.c:1467 shrink_inactive_list+0x4f4/0xe80 mm/vmscan.c:2075 shrink_list mm/vmscan.c:2294 [inline] shrink_lruvec+0x2246/0x2770 mm/vmscan.c:5473 shrink_node_memcgs mm/vmscan.c:5660 [inline] shrink_node+0xf0c/0x2690 mm/vmscan.c:5690 shrink_zones mm/vmscan.c:5896 [inline] do_try_to_free_pages+0x5db/0x1560 mm/vmscan.c:5954 try_to_free_mem_cgroup_pages+0x233/0x5b0 mm/vmscan.c:6272 try_charge+0x42b/0x14e0 mm/memcontrol.c:2745 __mem_cgroup_charge+0x14c/0x6d0 mm/memcontrol.c:6871 mem_cgroup_charge include/linux/memcontrol.h:458 [inline] __add_to_page_cache_locked+0x1e7/0x980 mm/filemap.c:854 add_to_page_cache_lru+0xa7/0x210 mm/filemap.c:948 pagecache_get_page+0x704/0x930 mm/filemap.c:1859 grab_cache_page_write_begin+0x59/0xb0 mm/filemap.c:3459 simple_write_begin+0x36/0x290 fs/libfs.c:531 generic_perform_write+0x2be/0x510 mm/filemap.c:3509 __generic_file_write_iter+0x24b/0x480 mm/filemap.c:3638 generic_file_write_iter+0xa9/0x1d0 mm/filemap.c:3670 __kernel_write+0x55a/0x910 fs/read_write.c:550 dump_emit+0x240/0x360 fs/coredump.c:855 dump_user_range+0x6a/0x1a0 fs/coredump.c:908 elf_core_dump+0x278a/0x2bc0 fs/binfmt_elf.c:2290 do_coredump+0x1ac9/0x27f0 fs/coredump.c:817 get_signal+0xf23/0x12e0 kernel/signal.c:2779 arch_do_signal_or_restart+0xbf/0x10f0 arch/x86/kernel/signal.c:805 handle_signal_work kernel/entry/common.c:145 [inline] exit_to_user_mode_loop+0xa2/0xe0 kernel/entry/common.c:169 exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:199 irqentry_exit_to_user_mode+0x9/0x10 kernel/entry/common.c:287 irqentry_exit+0x12/0x60 kernel/entry/common.c:375 exc_page_fault+0x67/0xc0 arch/x86/mm/fault.c:1487 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:571 RIP: 0033:0x7f28dbc46987 Code: 88 15 72 5d ec 00 88 05 6f 5d ec 00 c3 50 48 8d 35 19 26 1c 00 48 8d 3d 1f 26 1c 00 31 c0 e8 20 f7 ff ff 53 89 fb 48 83 ec 10 <64> 8b 04 25 94 ff ff ff 85 c0 74 2a 89 fe 31 c0 bf 3c 00 00 00 e8 RSP: 002b:00007f28da7cf120 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007f28dbd85fc9 RDX: 00007f28da7cf140 RSI: 00007f28da7cf270 RDI: 000000000000000b RBP: 00007f28dbe08f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f28dbfdd038 R14: 00007f28dbfdcfa0 R15: 00007fff5a9c61e8 Modules linked in: ---[ end trace 755455dd3ca4e2d1 ]--- RIP: 0010:f2fs_release_page+0x312/0x7d0 fs/f2fs/data.c:3615 Code: 4d 03 27 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 e7 e8 3f eb 97 ff 41 bf 58 07 00 00 4d 03 3c 24 4c 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 1d 04 00 00 45 8b 3f 44 89 fe 81 e6 00 RSP: 0018:ffffc90000c05e50 EFLAGS: 00010206 RAX: 00000000000000eb RBX: ffffea0004f61540 RCX: 0000000000000282 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00000000ffffffff RBP: ffffc90000c05e88 R08: 0000000000000004 R09: 0000000000000003 R10: fffffbfff0d8ee48 R11: 1ffffffff0d8ee48 R12: ffff888106dac3c8 R13: dffffc0000000000 R14: 1ffffd40009ec2a9 R15: 0000000000000758 FS: 0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffba6fb4ad8 CR3: 000000011284e000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 4d 03 27 add (%r15),%r12 3: 4c 89 e0 mov %r12,%rax 6: 48 c1 e8 03 shr $0x3,%rax a: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) f: 74 08 je 0x19 11: 4c 89 e7 mov %r12,%rdi 14: e8 3f eb 97 ff call 0xff97eb58 19: 41 bf 58 07 00 00 mov $0x758,%r15d 1f: 4d 03 3c 24 add (%r12),%r15 23: 4c 89 f8 mov %r15,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax <-- trapping instruction 2f: 84 c0 test %al,%al 31: 0f 85 1d 04 00 00 jne 0x454 37: 45 8b 3f mov (%r15),%r15d 3a: 44 89 fe mov %r15d,%esi 3d: 81 .byte 0x81 3e: e6 00 out %al,$0x0