loop4: detected capacity change from 0 to 512 EXT4-fs (loop4): ext4_check_descriptors: Checksum for group 0 failed (17031!=33349) ================================================================== 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:4867 Read of size 8 at addr ffff888054724eb0 by task syz.4.7878/22540 CPU: 1 PID: 22540 Comm: syz.4.7878 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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:4867 __ext4_fill_super fs/ext4/super.c:5423 [inline] ext4_fill_super+0x60c1/0x7dc0 fs/ext4/super.c:5687 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: 0033:0x7f36e699c14a 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:00007f36e790ce58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f36e790cee0 RCX: 00007f36e699c14a RDX: 0000200000000000 RSI: 0000200000000080 RDI: 00007f36e790cea0 RBP: 0000200000000000 R08: 00007f36e790cee0 R09: 0000000000000759 R10: 0000000000000759 R11: 0000000000000246 R12: 0000200000000080 R13: 00007f36e790cea0 R14: 00000000000004f8 R15: 0000200000000c00 Allocated by task 15073: 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] 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 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 reiserfs_fill_super+0x1475/0x23b0 fs/reiserfs/super.c:2078 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 The buggy address belongs to the object at ffff8880547248e0 which belongs to the cache reiser_inode_cache of size 1568 The buggy address is located 1488 bytes inside of 1568-byte region [ffff8880547248e0, ffff888054724f00) The buggy address belongs to the physical page: page:ffffea000151c800 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888054727740 pfn:0x54720 head:ffffea000151c800 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88807c60ab01 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff88801a733dc0 raw: ffff888054727740 000000008013000f 00000001ffffffff ffff88807c60ab01 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 5577, tgid 5576 (syz.3.431), ts 121732282344, free_ts 12995199172 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x1a1e/0x1ab0 mm/page_alloc.c:4328 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5614 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:1459 [inline] free_pcp_prepare mm/page_alloc.c:1509 [inline] free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3479 free_contig_range+0x9d/0x150 mm/page_alloc.c:9574 destroy_args+0xf0/0xa0a mm/debug_vm_pgtable.c:1031 debug_vm_pgtable+0x33c/0x38e mm/debug_vm_pgtable.c:1359 do_one_initcall+0x26a/0x840 init/main.c:1310 do_initcall_level+0x137/0x1e4 init/main.c:1383 do_initcalls+0x4b/0x8a init/main.c:1399 kernel_init_freeable+0x415/0x5be init/main.c:1638 kernel_init+0x19/0x1b0 init/main.c:1526 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Memory state around the buggy address: ffff888054724d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888054724e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888054724e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888054724f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888054724f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================