================================================================== BUG: KASAN: use-after-free in jfs_readdir+0x11ca/0x3c10 fs/jfs/jfs_dtree.c:3179 Read of size 8 at addr ffff88805a9b36f8 by task syz.3.284/5152 CPU: 0 PID: 5152 Comm: syz.3.284 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 jfs_readdir+0x11ca/0x3c10 fs/jfs/jfs_dtree.c:3179 iterate_dir+0x218/0x560 fs/readdir.c:-1 __do_sys_getdents fs/readdir.c:286 [inline] __se_sys_getdents+0xe5/0x250 fs/readdir.c:271 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f008c2cfba9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007f008a537038 EFLAGS: 00000246 ORIG_RAX: 000000000000004e RAX: ffffffffffffffda RBX: 00007f008c516fa0 RCX: 00007f008c2cfba9 RDX: fffffffffffffd90 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00007f008c352e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f008c517038 R14: 00007f008c516fa0 R15: 00007ffde82e06f8 Allocated by task 5152: 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:434 [inline] __kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x100/0x290 mm/slub.c:3238 mempool_alloc+0x18f/0x4e0 mm/mempool.c:393 alloc_metapage fs/jfs/jfs_metapage.c:175 [inline] __get_metapage+0x5e8/0x1060 fs/jfs/jfs_metapage.c:652 dtSplitRoot+0x1e5/0x1510 fs/jfs/jfs_dtree.c:1910 dtSplitUp fs/jfs/jfs_dtree.c:993 [inline] dtInsert+0xe20/0x57a0 fs/jfs/jfs_dtree.c:871 jfs_symlink+0x70f/0xe60 fs/jfs/namei.c:1019 vfs_symlink+0x247/0x3d0 fs/namei.c:4429 do_symlinkat+0x1be/0x6c0 fs/namei.c:4458 __do_sys_symlink fs/namei.c:4480 [inline] __se_sys_symlink fs/namei.c:4478 [inline] __x64_sys_symlink+0x7a/0x90 fs/namei.c:4478 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 5152: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kmem_cache_free+0x8f/0x210 mm/slub.c:3520 free_metapage fs/jfs/jfs_metapage.c:190 [inline] drop_metapage fs/jfs/jfs_metapage.c:227 [inline] release_metapage+0x97b/0xe10 fs/jfs/jfs_metapage.c:758 dtReadNext fs/jfs/jfs_dtree.c:3500 [inline] jfs_readdir+0xf6f/0x3c10 fs/jfs/jfs_dtree.c:3172 iterate_dir+0x218/0x560 fs/readdir.c:-1 __do_sys_getdents fs/readdir.c:286 [inline] __se_sys_getdents+0xe5/0x250 fs/readdir.c:271 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff88805a9b36c8 which belongs to the cache jfs_mp of size 184 The buggy address is located 48 bytes inside of 184-byte region [ffff88805a9b36c8, ffff88805a9b3780) The buggy address belongs to the page: page:ffffea00016a6cc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5a9b3 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 0000000000000000 dead000000000122 ffff8881469a4780 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x192800(GFP_NOWAIT|__GFP_NOWARN|__GFP_NORETRY|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4181, ts 91351556310, free_ts 89622515089 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x195/0x290 mm/slub.c:3238 mempool_alloc+0x18f/0x4e0 mm/mempool.c:393 alloc_metapage fs/jfs/jfs_metapage.c:175 [inline] __get_metapage+0x5e8/0x1060 fs/jfs/jfs_metapage.c:652 diSync+0xc0/0x890 fs/jfs/jfs_imap.c:216 diUnmount+0xc4/0x130 fs/jfs/jfs_imap.c:185 jfs_umount+0x10d/0x360 fs/jfs/jfs_umount.c:63 jfs_put_super+0x88/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x130/0x300 fs/super.c:475 kill_block_super+0x7c/0xe0 fs/super.c:1427 deactivate_locked_super+0x93/0xf0 fs/super.c:335 cleanup_mnt+0x418/0x4d0 fs/namespace.c:1139 task_work_run+0x125/0x1a0 kernel/task_work.c:188 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page_list+0x122/0x7e0 mm/page_alloc.c:3433 release_pages+0x184b/0x1bb0 mm/swap.c:963 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:240 [inline] tlb_flush_mmu mm/mmu_gather.c:247 [inline] tlb_finish_mmu+0x164/0x2e0 mm/mmu_gather.c:338 exit_mmap+0x3a6/0x5f0 mm/mmap.c:3218 __mmput+0x115/0x3b0 kernel/fork.c:1127 exit_mm+0x567/0x6c0 kernel/exit.c:550 do_exit+0x5a1/0x20a0 kernel/exit.c:870 do_group_exit+0x12e/0x300 kernel/exit.c:997 __do_sys_exit_group kernel/exit.c:1008 [inline] __se_sys_exit_group kernel/exit.c:1006 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Memory state around the buggy address: ffff88805a9b3580: fb fb fc fc fc fc fc fc fc fc 00 00 00 00 00 00 ffff88805a9b3600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88805a9b3680: 00 fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb ^ ffff88805a9b3700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805a9b3780: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ==================================================================