EXT4-fs (loop3): mounting ext2 file system using the ext4 subsystem ================================================================== BUG: KASAN: slab-use-after-free in check_igot_inode fs/ext4/inode.c:-1 [inline] BUG: KASAN: slab-use-after-free in __ext4_iget+0x2bd/0x3e70 fs/ext4/inode.c:4832 Read of size 8 at addr ffff8880694d1310 by task syz.3.1718/9810 CPU: 0 PID: 9810 Comm: syz.3.1718 Not tainted 6.6.101-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xac/0x220 mm/kasan/report.c:468 kasan_report+0x117/0x150 mm/kasan/report.c:581 check_igot_inode fs/ext4/inode.c:-1 [inline] __ext4_iget+0x2bd/0x3e70 fs/ext4/inode.c:4832 __ext4_fill_super fs/ext4/super.c:5502 [inline] ext4_fill_super+0x4a79/0x6620 fs/ext4/super.c:5729 get_tree_bdev+0x3e4/0x510 fs/super.c:1591 vfs_get_tree+0x8c/0x280 fs/super.c:1764 do_new_mount+0x24b/0xa40 fs/namespace.c:3371 do_mount fs/namespace.c:3711 [inline] __do_sys_mount fs/namespace.c:3920 [inline] __se_sys_mount+0x2da/0x3c0 fs/namespace.c:3897 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f6b0b79038a Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f6b0c66ee68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f6b0c66eef0 RCX: 00007f6b0b79038a RDX: 0000200000000080 RSI: 0000200000000140 RDI: 00007f6b0c66eeb0 RBP: 0000200000000080 R08: 00007f6b0c66eef0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000140 R13: 00007f6b0c66eeb0 R14: 000000000000059c R15: 0000200000000000 Allocated by task 6860: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3485 [inline] slab_alloc mm/slub.c:3493 [inline] __kmem_cache_alloc_lru mm/slub.c:3500 [inline] kmem_cache_alloc_lru+0x115/0x2e0 mm/slub.c:3516 alloc_inode_sb include/linux/fs.h:2946 [inline] reiserfs_alloc_inode+0x2a/0xc0 fs/reiserfs/super.c:642 alloc_inode fs/inode.c:261 [inline] iget5_locked+0xa2/0x260 fs/inode.c:1314 reiserfs_fill_super+0x1170/0x2340 fs/reiserfs/super.c:2053 mount_bdev+0x22b/0x2d0 fs/super.c:1643 legacy_get_tree+0xea/0x180 fs/fs_context.c:662 vfs_get_tree+0x8c/0x280 fs/super.c:1764 do_new_mount+0x24b/0xa40 fs/namespace.c:3371 do_mount fs/namespace.c:3711 [inline] __do_sys_mount fs/namespace.c:3920 [inline] __se_sys_mount+0x2da/0x3c0 fs/namespace.c:3897 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 __call_rcu_common kernel/rcu/tree.c:2721 [inline] call_rcu+0x158/0x930 kernel/rcu/tree.c:2837 destroy_inode fs/inode.c:316 [inline] evict+0x7db/0x870 fs/inode.c:720 dispose_list fs/inode.c:738 [inline] evict_inodes+0x5fe/0x690 fs/inode.c:792 generic_shutdown_super+0x97/0x2b0 fs/super.c:672 kill_block_super+0x44/0x90 fs/super.c:1660 deactivate_locked_super+0x97/0x100 fs/super.c:481 cleanup_mnt+0x429/0x4c0 fs/namespace.c:1250 task_work_run+0x1ce/0x250 kernel/task_work.c:239 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff8880694d0d40 which belongs to the cache reiser_inode_cache of size 1568 The buggy address is located 1488 bytes inside of freed 1568-byte region [ffff8880694d0d40, ffff8880694d1360) The buggy address belongs to the physical page: page:ffffea0001a53400 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880694d0000 pfn:0x694d0 head:ffffea0001a53400 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88802f772901 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888142aacc80 dead000000000122 0000000000000000 raw: ffff8880694d0000 0000000080130011 00000001ffffffff ffff88802f772901 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Reclaimable, gfp_mask 0x1d20d0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_RECLAIMABLE), pid 6329, tgid 6328 (syz.3.254), ts 110992635504, free_ts 110118976813 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554 prep_new_page mm/page_alloc.c:1561 [inline] get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457 alloc_slab_page+0x5d/0x170 mm/slub.c:1876 allocate_slab mm/slub.c:2023 [inline] new_slab+0x87/0x2e0 mm/slub.c:2076 ___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230 __slab_alloc mm/slub.c:3329 [inline] __slab_alloc_node mm/slub.c:3382 [inline] slab_alloc_node mm/slub.c:3475 [inline] slab_alloc mm/slub.c:3493 [inline] __kmem_cache_alloc_lru mm/slub.c:3500 [inline] kmem_cache_alloc_lru+0x1ae/0x2e0 mm/slub.c:3516 alloc_inode_sb include/linux/fs.h:2946 [inline] reiserfs_alloc_inode+0x2a/0xc0 fs/reiserfs/super.c:642 alloc_inode fs/inode.c:261 [inline] iget5_locked+0xa2/0x260 fs/inode.c:1314 reiserfs_fill_super+0x1170/0x2340 fs/reiserfs/super.c:2053 mount_bdev+0x22b/0x2d0 fs/super.c:1643 legacy_get_tree+0xea/0x180 fs/fs_context.c:662 vfs_get_tree+0x8c/0x280 fs/super.c:1764 do_new_mount+0x24b/0xa40 fs/namespace.c:3371 do_mount fs/namespace.c:3711 [inline] __do_sys_mount fs/namespace.c:3920 [inline] __se_sys_mount+0x2da/0x3c0 fs/namespace.c:3897 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1154 [inline] free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429 __slab_free+0x35e/0x410 mm/slub.c:3722 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3485 [inline] slab_alloc mm/slub.c:3493 [inline] __kmem_cache_alloc_lru mm/slub.c:3500 [inline] kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3509 getname_flags+0xbb/0x500 fs/namei.c:140 user_path_at_empty+0x2c/0x60 fs/namei.c:2908 do_readlinkat+0xd8/0x480 fs/stat.c:494 __do_sys_readlink fs/stat.c:527 [inline] __se_sys_readlink fs/stat.c:524 [inline] __x64_sys_readlink+0x7f/0x90 fs/stat.c:524 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Memory state around the buggy address: ffff8880694d1200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880694d1280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880694d1300: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff8880694d1380: fc fc fc fc fc fc fc fc fc fc fc fc 00 00 00 00 ffff8880694d1400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================