loop1: detected capacity change from 0 to 32768 ================================================================== BUG: KASA[ 157.286853][ T6360] BUG: KASAN: slab-use-after-free in jfs_readdir+0x18dc/0x33f0 fs/jfs/jfs_dtree.c:2903 Read of size 1 at addr ffff888034796120 by task syz.1.95/6360 CPU: 1 UID: 0 PID: 6360 Comm: syz.1.95 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 jfs_readdir+0x18dc/0x33f0 fs/jfs/jfs_dtree.c:2903 wrap_directory_iterator+0x99/0xe0 fs/readdir.c:67 iterate_dir+0x2f1/0x4e0 fs/readdir.c:110 __do_sys_getdents fs/readdir.c:319 [inline] __se_sys_getdents+0xf1/0x270 fs/readdir.c:304 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f017790de99 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0175b66028 EFLAGS: 00000246 ORIG_RAX: 000000000000004e RAX: ffffffffffffffda RBX: 00007f0177b95fa0 RCX: 00007f017790de99 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008 RBP: 00007f01779a3eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0177b96038 R14: 00007f0177b95fa0 R15: 00007ffc79413448 Allocated by task 6358: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4612 [inline] slab_alloc_node mm/slub.c:4945 [inline] kmem_cache_alloc_noprof+0x355/0x650 mm/slub.c:4959 alloc_filename fs/namei.c:147 [inline] do_getname+0x2e/0x250 fs/namei.c:187 getname include/linux/fs.h:2537 [inline] getname_maybe_null include/linux/fs.h:2544 [inline] class_filename_maybe_null_constructor include/linux/fs.h:2568 [inline] vfs_fstatat+0x45/0x170 fs/stat.c:368 __do_sys_newfstatat fs/stat.c:538 [inline] __se_sys_newfstatat fs/stat.c:532 [inline] __x64_sys_newfstatat+0x151/0x200 fs/stat.c:532 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6358: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2705 [inline] slab_free mm/slub.c:6405 [inline] kmem_cache_free+0x187/0x6c0 mm/slub.c:6532 class_filename_destructor include/linux/fs.h:2564 [inline] class_filename_maybe_null_destructor include/linux/fs.h:2568 [inline] vfs_fstatat+0x13d/0x170 fs/stat.c:375 __do_sys_newfstatat fs/stat.c:538 [inline] __se_sys_newfstatat fs/stat.c:532 [inline] __x64_sys_newfstatat+0x151/0x200 fs/stat.c:532 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888034796100 which belongs to the cache names_cache of size 192 The buggy address is located 32 bytes inside of freed 192-byte region [ffff888034796100, ffff8880347961c0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x34796 flags: 0x80000000000000(node=0|zone=1) page_type: f5(slab) raw: 0080000000000000 ffff88801b2f1500 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800100010 00000000f5000000 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 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6358, tgid 6358 (udevadm), ts 155876401518, free_ts 155857337627 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0x262a/0x26a0 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304 alloc_slab_page mm/slub.c:3294 [inline] allocate_slab+0x79/0x5e0 mm/slub.c:3408 new_slab mm/slub.c:3454 [inline] refill_objects+0x2d8/0x350 mm/slub.c:7338 refill_sheaf mm/slub.c:2832 [inline] __pcs_replace_empty_main+0x330/0x690 mm/slub.c:4703 alloc_from_pcs mm/slub.c:4801 [inline] slab_alloc_node mm/slub.c:4933 [inline] kmem_cache_alloc_noprof+0x452/0x650 mm/slub.c:4959 alloc_filename fs/namei.c:147 [inline] do_getname+0x2e/0x250 fs/namei.c:187 class_filename_flags_constructor include/linux/fs.h:2566 [inline] do_readlinkat+0xc8/0x510 fs/stat.c:569 __do_sys_readlink fs/stat.c:605 [inline] __se_sys_readlink fs/stat.c:602 [inline] __x64_sys_readlink+0x7f/0x90 fs/stat.c:602 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 6358 tgid 6358 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0x10e7/0x11c0 mm/page_alloc.c:2950 __slab_free+0x252/0x2a0 mm/slub.c:5767 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4612 [inline] slab_alloc_node mm/slub.c:4945 [inline] __do_kmalloc_node mm/slub.c:5361 [inline] __kvmalloc_node_noprof+0x54f/0x8a0 mm/slub.c:6933 seq_buf_alloc fs/seq_file.c:39 [inline] seq_read_iter+0x1eb/0xcb0 fs/seq_file.c:211 new_sync_read fs/read_write.c:493 [inline] vfs_read+0x59e/0xa90 fs/read_write.c:574 ksys_read+0x156/0x270 fs/read_write.c:716 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888034796000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888034796080: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff888034796100: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888034796180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888034796200: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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