loop0: detected capacity change from 0 to 512 ================================================================== BUG: KASAN: use-after-free in check_igot_inode fs/ext4/inode.c:-1 [inline] BUG: KASAN: use-after-free in __ext4_iget+0x2bb/0x3e40 fs/ext4/inode.c:4874 Read of size 8 at addr ffff888050809310 by task syz.0.8740/24432 CPU: 1 PID: 24432 Comm: syz.0.8740 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x210 mm/kasan/report.c:420 kasan_report+0x10b/0x140 mm/kasan/report.c:524 check_igot_inode fs/ext4/inode.c:-1 [inline] __ext4_iget+0x2bb/0x3e40 fs/ext4/inode.c:4874 __ext4_fill_super fs/ext4/super.c:5465 [inline] ext4_fill_super+0x6124/0x78c0 fs/ext4/super.c:5693 get_tree_bdev+0x3f1/0x610 fs/super.c:1366 vfs_get_tree+0x88/0x270 fs/super.c:1573 do_new_mount+0x24a/0xa40 fs/namespace.c:3078 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3606 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f20e9d9da8a Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f20eac97e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f20eac97ee0 RCX: 00007f20e9d9da8a RDX: 00002000000005c0 RSI: 0000200000000600 RDI: 00007f20eac97ea0 RBP: 00002000000005c0 R08: 00007f20eac97ee0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000600 R13: 00007f20eac97ea0 R14: 00000000000005bc R15: 00002000000000c0 Allocated by task 12335: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 __kasan_slab_alloc+0x6b/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc_lru+0x11a/0x2e0 mm/slub.c:3390 alloc_inode_sb include/linux/fs.h:3245 [inline] reiserfs_alloc_inode+0x26/0xc0 fs/reiserfs/super.c:642 alloc_inode fs/inode.c:261 [inline] new_inode_pseudo+0x5f/0x1c0 fs/inode.c:1063 new_inode+0x25/0x1c0 fs/inode.c:1091 reiserfs_mkdir+0x1d2/0x920 fs/reiserfs/namei.c:815 xattr_mkdir fs/reiserfs/xattr.c:76 [inline] create_privroot fs/reiserfs/xattr.c:882 [inline] reiserfs_xattr_init+0x331/0x720 fs/reiserfs/xattr.c:1005 reiserfs_fill_super+0x1fee/0x23b0 fs/reiserfs/super.c:2175 mount_bdev+0x287/0x3c0 fs/super.c:1443 legacy_get_tree+0xe6/0x180 fs/fs_context.c:632 vfs_get_tree+0x88/0x270 fs/super.c:1573 do_new_mount+0x24a/0xa40 fs/namespace.c:3078 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3606 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486 call_rcu+0x14f/0x990 kernel/rcu/tree.c:2849 destroy_inode fs/inode.c:316 [inline] evict+0x834/0x8d0 fs/inode.c:720 dispose_list fs/inode.c:738 [inline] evict_inodes+0x60c/0x6a0 fs/inode.c:792 generic_shutdown_super+0x93/0x340 fs/super.c:480 kill_block_super+0x7c/0xe0 fs/super.c:1470 deactivate_locked_super+0x93/0xf0 fs/super.c:332 cleanup_mnt+0x42c/0x4b0 fs/namespace.c:1191 task_work_run+0x1d0/0x260 kernel/task_work.c:203 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+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff888050808d40 which belongs to the cache reiser_inode_cache of size 1568 The buggy address is located 1488 bytes inside of 1568-byte region [ffff888050808d40, ffff888050809360) The buggy address belongs to the physical page: page:ffffea0001420200 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88805080ae60 pfn:0x50808 head:ffffea0001420200 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff8880756de001 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888146eb4000 raw: ffff88805080ae60 000000008013000c 00000001ffffffff ffff8880756de001 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 11681, tgid 11680 (syz.1.3229), ts 454875552715, free_ts 305707449608 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2559 prep_new_page mm/page_alloc.c:2566 [inline] get_page_from_freelist+0x1a1e/0x1ab0 mm/page_alloc.c:4357 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5657 alloc_slab_page+0x5d/0x160 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2c0 mm/slub.c:1997 ___slab_alloc+0xbc6/0x1240 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc_lru+0x1ae/0x2e0 mm/slub.c:3390 alloc_inode_sb include/linux/fs.h:3245 [inline] reiserfs_alloc_inode+0x26/0xc0 fs/reiserfs/super.c:642 alloc_inode fs/inode.c:261 [inline] iget5_locked+0x9e/0x260 fs/inode.c:1328 reiserfs_fill_super+0x11d3/0x23b0 fs/reiserfs/super.c:2053 mount_bdev+0x287/0x3c0 fs/super.c:1443 legacy_get_tree+0xe6/0x180 fs/fs_context.c:632 vfs_get_tree+0x88/0x270 fs/super.c:1573 do_new_mount+0x24a/0xa40 fs/namespace.c:3078 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3606 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1486 [inline] free_pcp_prepare mm/page_alloc.c:1536 [inline] free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3413 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3508 free_slab mm/slub.c:2036 [inline] discard_slab mm/slub.c:2042 [inline] __unfreeze_partials+0x1a5/0x200 mm/slub.c:2591 put_cpu_partial+0x17c/0x250 mm/slub.c:2667 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc_lru+0x11a/0x2e0 mm/slub.c:3390 __d_alloc+0x31/0x700 fs/dcache.c:1774 d_alloc+0x4a/0x250 fs/dcache.c:1854 lookup_one_qstr_excl+0xc6/0x240 fs/namei.c:1609 filename_create+0x23a/0x470 fs/namei.c:3885 do_symlinkat+0xc1/0x400 fs/namei.c:4498 __do_sys_symlinkat fs/namei.c:4525 [inline] __se_sys_symlinkat fs/namei.c:4522 [inline] __x64_sys_symlinkat+0x95/0xa0 fs/namei.c:4522 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 Memory state around the buggy address: ffff888050809200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888050809280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888050809300: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff888050809380: fc fc fc fc fc fc fc fc fc fc fc fc 00 00 00 00 ffff888050809400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================