[{"id":3678949,"web_url":"http://patchwork.ozlabs.org/comment/3678949/","msgid":"<69e32908.a00a0220.1bd0ca.003f.GAE@google.com>","list_archive_url":null,"date":"2026-04-18T06:47:36","subject":"[syzbot ci] Re: Data in direntry (dirdata) feature","submitter":{"id":93183,"url":"http://patchwork.ozlabs.org/api/people/93183/","name":"syzbot ci","email":"syzbot+ci6167b51351f50705@syzkaller.appspotmail.com"},"content":"syzbot ci has tested the following series\n\n[v1] Data in direntry (dirdata) feature\nhttps://lore.kernel.org/all/20260417213723.74204-1-artem.blagodarenko@gmail.com\n* [PATCH 1/3] ext4: make dirdata work with metadata_csum\n* [PATCH 2/3] ext4: add dirdata support structures and helpers\n* [PATCH 3/3] ext4: dirdata feature\n\nand found the following issues:\n* KASAN: slab-out-of-bounds Read in __ext4_check_dir_entry\n* KASAN: slab-out-of-bounds Read in dx_probe\n* KASAN: slab-use-after-free Read in __ext4_check_dir_entry\n* KASAN: slab-use-after-free Read in dx_probe\n* KASAN: use-after-free Read in __ext4_check_dir_entry\n\nFull report is available here:\nhttps://ci.syzbot.org/series/590e846e-42c0-4497-b6ae-b95ed4468941\n\n***\n\nKASAN: slab-out-of-bounds Read in __ext4_check_dir_entry\n\ntree:      torvalds\nURL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux\nbase:      70b672833f4025341c11b22c7f83778a5cd611bc\narch:      amd64\ncompiler:  Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8\nconfig:    https://ci.syzbot.org/builds/7b860156-1ca9-441f-b899-ebfb5a09620d/config\nsyz repro: https://ci.syzbot.org/findings/d27eccd2-4663-4047-abb9-9c24cb32f887/syz_repro\n\nloop0: lost filesystem error report for type 5 error -117\nEXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.\n==================================================================\nBUG: KASAN: slab-out-of-bounds in ext4_dirent_get_data_len fs/ext4/ext4.h:4040 [inline]\nBUG: KASAN: slab-out-of-bounds in ext4_dir_entry_len fs/ext4/ext4.h:4060 [inline]\nBUG: KASAN: slab-out-of-bounds in __ext4_check_dir_entry+0x527/0xa70 fs/ext4/dir.c:96\nRead of size 1 at addr ffff8881090bfe5c by task syz.0.20/5967\n\nCPU: 1 UID: 0 PID: 5967 Comm: syz.0.20 Not tainted syzkaller #0 PREEMPT(full) \nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014\nCall Trace:\n <TASK>\n dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:378 [inline]\n print_report+0xba/0x230 mm/kasan/report.c:482\n kasan_report+0x117/0x150 mm/kasan/report.c:595\n ext4_dirent_get_data_len fs/ext4/ext4.h:4040 [inline]\n ext4_dir_entry_len fs/ext4/ext4.h:4060 [inline]\n __ext4_check_dir_entry+0x527/0xa70 fs/ext4/dir.c:96\n ext4_inlinedir_to_tree+0x6be/0xbf0 fs/ext4/inline.c:1322\n ext4_htree_fill_tree+0x50b/0x1230 fs/ext4/namei.c:1184\n ext4_dx_readdir fs/ext4/dir.c:600 [inline]\n ext4_readdir+0x2f7b/0x3870 fs/ext4/dir.c:146\n iterate_dir+0x399/0x570 fs/readdir.c:108\n __do_sys_getdents64 fs/readdir.c:412 [inline]\n __se_sys_getdents64+0xf1/0x280 fs/readdir.c:397\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7fe47219c819\nCode: 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\nRSP: 002b:00007fe4730c0028 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9\nRAX: ffffffffffffffda RBX: 00007fe472415fa0 RCX: 00007fe47219c819\nRDX: 000000000000ff80 RSI: 9999999999999999 RDI: 0000000000000004\nRBP: 00007fe472232c91 R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000\nR13: 00007fe472416038 R14: 00007fe472415fa0 R15: 00007ffff595c618\n </TASK>\n\nAllocated by task 5967:\n kasan_save_stack mm/kasan/common.c:57 [inline]\n kasan_save_track+0x3e/0x80 mm/kasan/common.c:78\n poison_kmalloc_redzone mm/kasan/common.c:398 [inline]\n __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415\n kasan_kmalloc include/linux/kasan.h:263 [inline]\n __do_kmalloc_node mm/slub.c:5260 [inline]\n __kmalloc_noprof+0x35c/0x760 mm/slub.c:5272\n kmalloc_noprof include/linux/slab.h:954 [inline]\n ext4_mb_init+0x15d/0x2ad0 fs/ext4/mballoc.c:3729\n __ext4_fill_super fs/ext4/super.c:5623 [inline]\n ext4_fill_super+0x5647/0x6320 fs/ext4/super.c:5793\n get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694\n vfs_get_tree+0x92/0x2a0 fs/super.c:1754\n fc_mount fs/namespace.c:1193 [inline]\n do_new_mount_fc fs/namespace.c:3763 [inline]\n do_new_mount+0x341/0xd30 fs/namespace.c:3839\n do_mount fs/namespace.c:4172 [inline]\n __do_sys_mount fs/namespace.c:4361 [inline]\n __se_sys_mount+0x31d/0x420 fs/namespace.c:4338\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nThe buggy address belongs to the object at ffff8881090bfe00\n which belongs to the cache kmalloc-64 of size 64\nThe buggy address is located 44 bytes to the right of\n allocated 48-byte region [ffff8881090bfe00, ffff8881090bfe30)\n\nThe buggy address belongs to the physical page:\npage: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1090bf\nflags: 0x17ff00000000000(node=0|zone=2|lastcpupid=0x7ff)\npage_type: f5(slab)\nraw: 017ff00000000000 ffff8881000418c0 dead000000000100 dead000000000122\nraw: 0000000000000000 0000000800200020 00000000f5000000 0000000000000000\npage dumped because: kasan: bad access detected\npage_owner tracks the page as allocated\npage last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 16414655371, free_ts 15537272896\n set_page_owner include/linux/page_owner.h:32 [inline]\n post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889\n prep_new_page mm/page_alloc.c:1897 [inline]\n get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962\n __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250\n alloc_slab_page mm/slub.c:3292 [inline]\n allocate_slab+0x77/0x660 mm/slub.c:3481\n new_slab mm/slub.c:3539 [inline]\n refill_objects+0x331/0x3c0 mm/slub.c:7175\n refill_sheaf mm/slub.c:2812 [inline]\n __pcs_replace_empty_main+0x2e6/0x730 mm/slub.c:4615\n alloc_from_pcs mm/slub.c:4717 [inline]\n slab_alloc_node mm/slub.c:4851 [inline]\n __do_kmalloc_node mm/slub.c:5259 [inline]\n __kmalloc_noprof+0x474/0x760 mm/slub.c:5272\n kmalloc_noprof include/linux/slab.h:954 [inline]\n kzalloc_noprof include/linux/slab.h:1188 [inline]\n kobject_get_path+0xc5/0x2f0 lib/kobject.c:161\n kobject_uevent_env+0x2a1/0x9e0 lib/kobject_uevent.c:545\n really_probe+0x789/0xaf0 drivers/base/dd.c:771\n __driver_probe_device+0x18c/0x320 drivers/base/dd.c:863\n driver_probe_device+0x4f/0x240 drivers/base/dd.c:893\n __device_attach_driver+0x279/0x430 drivers/base/dd.c:1021\n bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500\n __device_attach+0x2c5/0x450 drivers/base/dd.c:1093\n device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1148\npage last free pid 33 tgid 33 stack trace:\n reset_page_owner include/linux/page_owner.h:25 [inline]\n __free_pages_prepare mm/page_alloc.c:1433 [inline]\n __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978\n vfree+0x25a/0x400 mm/vmalloc.c:3479\n delayed_vfree_work+0x55/0x80 mm/vmalloc.c:3398\n process_one_work kernel/workqueue.c:3276 [inline]\n process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359\n worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440\n kthread+0x388/0x470 kernel/kthread.c:436\n ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245\n\nMemory state around the buggy address:\n ffff8881090bfd00: 00 00 00 00 00 00 00 04 fc fc fc fc fc fc fc fc\n ffff8881090bfd80: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc\n>ffff8881090bfe00: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc\n                                                    ^\n ffff8881090bfe80: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc\n ffff8881090bff00: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc\n==================================================================\n\n\n***\n\nKASAN: slab-out-of-bounds Read in dx_probe\n\ntree:      torvalds\nURL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux\nbase:      70b672833f4025341c11b22c7f83778a5cd611bc\narch:      amd64\ncompiler:  Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8\nconfig:    https://ci.syzbot.org/builds/7b860156-1ca9-441f-b899-ebfb5a09620d/config\nsyz repro: https://ci.syzbot.org/findings/a5fcf3bd-f1ae-4b81-b5d2-f96899ea7690/syz_repro\n\n==================================================================\nBUG: KASAN: slab-out-of-bounds in ext4_dir_entry_is_tail fs/ext4/ext4.h:4001 [inline]\nBUG: KASAN: slab-out-of-bounds in ext4_dirent_get_data_len fs/ext4/ext4.h:4024 [inline]\nBUG: KASAN: slab-out-of-bounds in ext4_dir_entry_len fs/ext4/ext4.h:4060 [inline]\nBUG: KASAN: slab-out-of-bounds in dx_root_limit fs/ext4/namei.c:583 [inline]\nBUG: KASAN: slab-out-of-bounds in dx_probe+0x1ac9/0x1d90 fs/ext4/namei.c:861\nRead of size 4 at addr ffff88816a408c10 by task syz.2.19/5980\n\nCPU: 1 UID: 0 PID: 5980 Comm: syz.2.19 Not tainted syzkaller #0 PREEMPT(full) \nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014\nCall Trace:\n <TASK>\n dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:378 [inline]\n print_report+0xba/0x230 mm/kasan/report.c:482\n kasan_report+0x117/0x150 mm/kasan/report.c:595\n ext4_dir_entry_is_tail fs/ext4/ext4.h:4001 [inline]\n ext4_dirent_get_data_len fs/ext4/ext4.h:4024 [inline]\n ext4_dir_entry_len fs/ext4/ext4.h:4060 [inline]\n dx_root_limit fs/ext4/namei.c:583 [inline]\n dx_probe+0x1ac9/0x1d90 fs/ext4/namei.c:861\n ext4_dx_find_entry fs/ext4/namei.c:1812 [inline]\n __ext4_find_entry+0x5a9/0x2140 fs/ext4/namei.c:1652\n ext4_lookup_entry fs/ext4/namei.c:1794 [inline]\n ext4_lookup+0x17b/0x710 fs/ext4/namei.c:1860\n __lookup_slow+0x2b7/0x410 fs/namei.c:1916\n lookup_slow+0x53/0x70 fs/namei.c:1933\n walk_component fs/namei.c:2279 [inline]\n lookup_last fs/namei.c:2780 [inline]\n path_lookupat+0x3f5/0x8c0 fs/namei.c:2804\n filename_lookup+0x256/0x5d0 fs/namei.c:2833\n user_path_at+0x40/0x160 fs/namei.c:3612\n do_mount fs/namespace.c:4169 [inline]\n __do_sys_mount fs/namespace.c:4361 [inline]\n __se_sys_mount+0x2dc/0x420 fs/namespace.c:4338\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7f518919c819\nCode: 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\nRSP: 002b:00007f5189fbb028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5\nRAX: ffffffffffffffda RBX: 00007f5189415fa0 RCX: 00007f518919c819\nRDX: 0000200000000140 RSI: 0000200000000100 RDI: 0000000000000000\nRBP: 00007f5189232c91 R08: 0000200000000d80 R09: 0000000000000000\nR10: 0000000001302060 R11: 0000000000000246 R12: 0000000000000000\nR13: 00007f5189416038 R14: 00007f5189415fa0 R15: 00007ffc5d8d15b8\n </TASK>\n\nAllocated by task 5243:\n kasan_save_stack mm/kasan/common.c:57 [inline]\n kasan_save_track+0x3e/0x80 mm/kasan/common.c:78\n poison_kmalloc_redzone mm/kasan/common.c:398 [inline]\n __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415\n kasan_kmalloc include/linux/kasan.h:263 [inline]\n __do_kmalloc_node mm/slub.c:5260 [inline]\n __kvmalloc_node_noprof+0x528/0x8a0 mm/slub.c:6752\n evdev_open+0xeb/0x5b0 drivers/input/evdev.c:468\n chrdev_open+0x4cd/0x5e0 fs/char_dev.c:411\n do_dentry_open+0x785/0x14e0 fs/open.c:949\n vfs_open+0x3b/0x340 fs/open.c:1081\n do_open fs/namei.c:4671 [inline]\n path_openat+0x2e08/0x3860 fs/namei.c:4830\n do_file_open+0x23e/0x4a0 fs/namei.c:4859\n do_sys_openat2+0x113/0x200 fs/open.c:1366\n do_sys_open fs/open.c:1372 [inline]\n __do_sys_openat fs/open.c:1388 [inline]\n __se_sys_openat fs/open.c:1383 [inline]\n __x64_sys_openat+0x138/0x170 fs/open.c:1383\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nThe buggy address belongs to the object at ffff88816a408000\n which belongs to the cache kmalloc-2k of size 2048\nThe buggy address is located 1088 bytes to the right of\n allocated 2000-byte region [ffff88816a408000, ffff88816a4087d0)\n\nThe buggy address belongs to the physical page:\npage: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x16a408\nhead: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0\nflags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)\npage_type: f5(slab)\nraw: 057ff00000000040 ffff888100042000 dead000000000100 dead000000000122\nraw: 0000000000000000 0000000800080008 00000000f5000000 0000000000000000\nhead: 057ff00000000040 ffff888100042000 dead000000000100 dead000000000122\nhead: 0000000000000000 0000000800080008 00000000f5000000 0000000000000000\nhead: 057ff00000000003 ffffea0005a90201 00000000ffffffff 00000000ffffffff\nhead: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008\npage dumped because: kasan: bad access detected\npage_owner tracks the page as allocated\npage last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5243, tgid 5243 (acpid), ts 25906150911, free_ts 21905842969\n set_page_owner include/linux/page_owner.h:32 [inline]\n post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889\n prep_new_page mm/page_alloc.c:1897 [inline]\n get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962\n __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250\n alloc_slab_page mm/slub.c:3292 [inline]\n allocate_slab+0x77/0x660 mm/slub.c:3481\n new_slab mm/slub.c:3539 [inline]\n refill_objects+0x331/0x3c0 mm/slub.c:7175\n refill_sheaf mm/slub.c:2812 [inline]\n __pcs_replace_empty_main+0x2e6/0x730 mm/slub.c:4615\n alloc_from_pcs mm/slub.c:4717 [inline]\n slab_alloc_node mm/slub.c:4851 [inline]\n __do_kmalloc_node mm/slub.c:5259 [inline]\n __kvmalloc_node_noprof+0x657/0x8a0 mm/slub.c:6752\n evdev_open+0xeb/0x5b0 drivers/input/evdev.c:468\n chrdev_open+0x4cd/0x5e0 fs/char_dev.c:411\n do_dentry_open+0x785/0x14e0 fs/open.c:949\n vfs_open+0x3b/0x340 fs/open.c:1081\n do_open fs/namei.c:4671 [inline]\n path_openat+0x2e08/0x3860 fs/namei.c:4830\n do_file_open+0x23e/0x4a0 fs/namei.c:4859\n do_sys_openat2+0x113/0x200 fs/open.c:1366\n do_sys_open fs/open.c:1372 [inline]\n __do_sys_openat fs/open.c:1388 [inline]\n __se_sys_openat fs/open.c:1383 [inline]\n __x64_sys_openat+0x138/0x170 fs/open.c:1383\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94\npage last free pid 9 tgid 9 stack trace:\n reset_page_owner include/linux/page_owner.h:25 [inline]\n __free_pages_prepare mm/page_alloc.c:1433 [inline]\n __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978\n vfree+0x25a/0x400 mm/vmalloc.c:3479\n delayed_vfree_work+0x55/0x80 mm/vmalloc.c:3398\n process_one_work kernel/workqueue.c:3276 [inline]\n process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359\n worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440\n kthread+0x388/0x470 kernel/kthread.c:436\n ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245\n\nMemory state around the buggy address:\n ffff88816a408b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc\n ffff88816a408b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc\n>ffff88816a408c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc\n                         ^\n ffff88816a408c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc\n ffff88816a408d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc\n==================================================================\n\n\n***\n\nKASAN: slab-use-after-free Read in __ext4_check_dir_entry\n\ntree:      torvalds\nURL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux\nbase:      70b672833f4025341c11b22c7f83778a5cd611bc\narch:      amd64\ncompiler:  Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8\nconfig:    https://ci.syzbot.org/builds/7b860156-1ca9-441f-b899-ebfb5a09620d/config\nsyz repro: https://ci.syzbot.org/findings/e493ff66-4032-4979-9b5d-5118b2768ca5/syz_repro\n\nEXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.\n==================================================================\nBUG: KASAN: slab-use-after-free in ext4_dirent_get_data_len fs/ext4/ext4.h:4040 [inline]\nBUG: KASAN: slab-use-after-free in ext4_dir_entry_len fs/ext4/ext4.h:4060 [inline]\nBUG: KASAN: slab-use-after-free in __ext4_check_dir_entry+0x527/0xa70 fs/ext4/dir.c:96\nRead of size 1 at addr ffff88810138889c by task syz.0.24/5978\n\nCPU: 0 UID: 0 PID: 5978 Comm: syz.0.24 Not tainted syzkaller #0 PREEMPT(full) \nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014\nCall Trace:\n <TASK>\n dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:378 [inline]\n print_report+0xba/0x230 mm/kasan/report.c:482\n kasan_report+0x117/0x150 mm/kasan/report.c:595\n ext4_dirent_get_data_len fs/ext4/ext4.h:4040 [inline]\n ext4_dir_entry_len fs/ext4/ext4.h:4060 [inline]\n __ext4_check_dir_entry+0x527/0xa70 fs/ext4/dir.c:96\n ext4_inlinedir_to_tree+0x6be/0xbf0 fs/ext4/inline.c:1322\n ext4_htree_fill_tree+0x50b/0x1230 fs/ext4/namei.c:1184\n ext4_dx_readdir fs/ext4/dir.c:600 [inline]\n ext4_readdir+0x2f7b/0x3870 fs/ext4/dir.c:146\n iterate_dir+0x399/0x570 fs/readdir.c:108\n __do_sys_getdents64 fs/readdir.c:412 [inline]\n __se_sys_getdents64+0xf1/0x280 fs/readdir.c:397\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7ff3fe19c819\nCode: 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\nRSP: 002b:00007ff3fefac028 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9\nRAX: ffffffffffffffda RBX: 00007ff3fe415fa0 RCX: 00007ff3fe19c819\nRDX: 000000000000ff80 RSI: 9999999999999999 RDI: 0000000000000004\nRBP: 00007ff3fe232c91 R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000\nR13: 00007ff3fe416038 R14: 00007ff3fe415fa0 R15: 00007ffd39a74998\n </TASK>\n\nAllocated by task 5766:\n kasan_save_stack mm/kasan/common.c:57 [inline]\n kasan_save_track+0x3e/0x80 mm/kasan/common.c:78\n poison_kmalloc_redzone mm/kasan/common.c:398 [inline]\n __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415\n kasan_kmalloc include/linux/kasan.h:263 [inline]\n __do_kmalloc_node mm/slub.c:5260 [inline]\n __kmalloc_noprof+0x35c/0x760 mm/slub.c:5272\n kmalloc_noprof include/linux/slab.h:954 [inline]\n kzalloc_noprof include/linux/slab.h:1188 [inline]\n tomoyo_encode2 security/tomoyo/realpath.c:45 [inline]\n tomoyo_encode+0x28b/0x550 security/tomoyo/realpath.c:80\n tomoyo_realpath_from_path+0x58d/0x5d0 security/tomoyo/realpath.c:283\n tomoyo_get_realpath security/tomoyo/file.c:151 [inline]\n tomoyo_check_open_permission+0x229/0x470 security/tomoyo/file.c:776\n security_file_open+0xa9/0x240 security/security.c:2637\n do_dentry_open+0x384/0x14e0 fs/open.c:926\n vfs_open+0x3b/0x340 fs/open.c:1081\n do_open fs/namei.c:4671 [inline]\n path_openat+0x2e08/0x3860 fs/namei.c:4830\n do_file_open+0x23e/0x4a0 fs/namei.c:4859\n do_sys_openat2+0x113/0x200 fs/open.c:1366\n do_sys_open fs/open.c:1372 [inline]\n __do_sys_openat fs/open.c:1388 [inline]\n __se_sys_openat fs/open.c:1383 [inline]\n __x64_sys_openat+0x138/0x170 fs/open.c:1383\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nFreed by task 5766:\n kasan_save_stack mm/kasan/common.c:57 [inline]\n kasan_save_track+0x3e/0x80 mm/kasan/common.c:78\n kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584\n poison_slab_object mm/kasan/common.c:253 [inline]\n __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285\n kasan_slab_free include/linux/kasan.h:235 [inline]\n slab_free_hook mm/slub.c:2685 [inline]\n slab_free mm/slub.c:6165 [inline]\n kfree+0x1c1/0x630 mm/slub.c:6483\n tomoyo_check_open_permission+0x32c/0x470 security/tomoyo/file.c:791\n security_file_open+0xa9/0x240 security/security.c:2637\n do_dentry_open+0x384/0x14e0 fs/open.c:926\n vfs_open+0x3b/0x340 fs/open.c:1081\n do_open fs/namei.c:4671 [inline]\n path_openat+0x2e08/0x3860 fs/namei.c:4830\n do_file_open+0x23e/0x4a0 fs/namei.c:4859\n do_sys_openat2+0x113/0x200 fs/open.c:1366\n do_sys_open fs/open.c:1372 [inline]\n __do_sys_openat fs/open.c:1388 [inline]\n __se_sys_openat fs/open.c:1383 [inline]\n __x64_sys_openat+0x138/0x170 fs/open.c:1383\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nThe buggy address belongs to the object at ffff888101388880\n which belongs to the cache kmalloc-64 of size 64\nThe buggy address is located 28 bytes inside of\n freed 64-byte region [ffff888101388880, ffff8881013888c0)\n\nThe buggy address belongs to the physical page:\npage: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x101388\nflags: 0x17ff00000000000(node=0|zone=2|lastcpupid=0x7ff)\npage_type: f5(slab)\nraw: 017ff00000000000 ffff8881000418c0 dead000000000100 dead000000000122\nraw: 0000000000000000 0000000800200020 00000000f5000000 0000000000000000\npage dumped because: kasan: bad access detected\npage_owner tracks the page as allocated\npage last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 26, tgid 26 (kworker/u9:0), ts 4100832473, free_ts 4100767003\n set_page_owner include/linux/page_owner.h:32 [inline]\n post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889\n prep_new_page mm/page_alloc.c:1897 [inline]\n get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962\n __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250\n alloc_slab_page mm/slub.c:3292 [inline]\n allocate_slab+0x77/0x660 mm/slub.c:3481\n new_slab mm/slub.c:3539 [inline]\n refill_objects+0x331/0x3c0 mm/slub.c:7175\n refill_sheaf mm/slub.c:2812 [inline]\n alloc_full_sheaf mm/slub.c:2834 [inline]\n __pcs_replace_empty_main+0x40a/0x730 mm/slub.c:4626\n alloc_from_pcs mm/slub.c:4717 [inline]\n slab_alloc_node mm/slub.c:4851 [inline]\n __do_kmalloc_node mm/slub.c:5259 [inline]\n __kmalloc_noprof+0x474/0x760 mm/slub.c:5272\n kmalloc_noprof include/linux/slab.h:954 [inline]\n kzalloc_noprof include/linux/slab.h:1188 [inline]\n lsm_blob_alloc security/security.c:193 [inline]\n lsm_task_alloc security/security.c:245 [inline]\n security_task_alloc+0x4d/0x330 security/security.c:2683\n copy_process+0x16df/0x3cd0 kernel/fork.c:2206\n kernel_clone+0x248/0x8e0 kernel/fork.c:2658\n user_mode_thread+0x110/0x180 kernel/fork.c:2734\n call_usermodehelper_exec_work+0x5c/0x230 kernel/umh.c:171\n process_one_work kernel/workqueue.c:3276 [inline]\n process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359\n worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440\n kthread+0x388/0x470 kernel/kthread.c:436\n ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158\npage last free pid 26 tgid 26 stack trace:\n reset_page_owner include/linux/page_owner.h:25 [inline]\n __free_pages_prepare mm/page_alloc.c:1433 [inline]\n __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978\n __kasan_populate_vmalloc_do mm/kasan/shadow.c:393 [inline]\n __kasan_populate_vmalloc+0x1b2/0x1d0 mm/kasan/shadow.c:424\n kasan_populate_vmalloc include/linux/kasan.h:580 [inline]\n alloc_vmap_area+0xd73/0x14b0 mm/vmalloc.c:2129\n __get_vm_area_node+0x1f8/0x300 mm/vmalloc.c:3232\n __vmalloc_node_range_noprof+0x372/0x1730 mm/vmalloc.c:4024\n __vmalloc_node_noprof+0xc2/0x100 mm/vmalloc.c:4124\n alloc_thread_stack_node kernel/fork.c:355 [inline]\n dup_task_struct+0x292/0x9e0 kernel/fork.c:924\n copy_process+0x508/0x3cd0 kernel/fork.c:2051\n kernel_clone+0x248/0x8e0 kernel/fork.c:2658\n user_mode_thread+0x110/0x180 kernel/fork.c:2734\n call_usermodehelper_exec_work+0x5c/0x230 kernel/umh.c:171\n process_one_work kernel/workqueue.c:3276 [inline]\n process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359\n worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440\n kthread+0x388/0x470 kernel/kthread.c:436\n ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245\n\nMemory state around the buggy address:\n ffff888101388780: 00 00 00 00 00 00 00 04 fc fc fc fc fc fc fc fc\n ffff888101388800: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc\n>ffff888101388880: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc\n                            ^\n ffff888101388900: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc\n ffff888101388980: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc\n==================================================================\n\n\n***\n\nKASAN: slab-use-after-free Read in dx_probe\n\ntree:      torvalds\nURL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux\nbase:      70b672833f4025341c11b22c7f83778a5cd611bc\narch:      amd64\ncompiler:  Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8\nconfig:    https://ci.syzbot.org/builds/7b860156-1ca9-441f-b899-ebfb5a09620d/config\nsyz repro: https://ci.syzbot.org/findings/5524eff5-62fb-4cff-8d4e-7e3750aa921b/syz_repro\n\nEXT4-fs (loop2): mounted filesystem 00000000-0000-0000-0000-000000000000 ro without journal. Quota mode: none.\n==================================================================\nBUG: KASAN: slab-use-after-free in ext4_dir_entry_is_tail fs/ext4/ext4.h:4001 [inline]\nBUG: KASAN: slab-use-after-free in ext4_dirent_get_data_len fs/ext4/ext4.h:4024 [inline]\nBUG: KASAN: slab-use-after-free in ext4_dir_entry_len fs/ext4/ext4.h:4060 [inline]\nBUG: KASAN: slab-use-after-free in dx_root_limit fs/ext4/namei.c:583 [inline]\nBUG: KASAN: slab-use-after-free in dx_probe+0x1ac9/0x1d90 fs/ext4/namei.c:861\nRead of size 4 at addr ffff888109c42c10 by task syz.2.20/5984\n\nCPU: 0 UID: 0 PID: 5984 Comm: syz.2.20 Not tainted syzkaller #0 PREEMPT(full) \nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014\nCall Trace:\n <TASK>\n dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:378 [inline]\n print_report+0xba/0x230 mm/kasan/report.c:482\n kasan_report+0x117/0x150 mm/kasan/report.c:595\n ext4_dir_entry_is_tail fs/ext4/ext4.h:4001 [inline]\n ext4_dirent_get_data_len fs/ext4/ext4.h:4024 [inline]\n ext4_dir_entry_len fs/ext4/ext4.h:4060 [inline]\n dx_root_limit fs/ext4/namei.c:583 [inline]\n dx_probe+0x1ac9/0x1d90 fs/ext4/namei.c:861\n ext4_dx_find_entry fs/ext4/namei.c:1812 [inline]\n __ext4_find_entry+0x5a9/0x2140 fs/ext4/namei.c:1652\n ext4_lookup_entry fs/ext4/namei.c:1794 [inline]\n ext4_lookup+0x17b/0x710 fs/ext4/namei.c:1860\n lookup_open fs/namei.c:4456 [inline]\n open_last_lookups fs/namei.c:4583 [inline]\n path_openat+0x11ac/0x3860 fs/namei.c:4827\n do_file_open+0x23e/0x4a0 fs/namei.c:4859\n do_sys_openat2+0x113/0x200 fs/open.c:1366\n do_sys_open fs/open.c:1372 [inline]\n __do_sys_openat fs/open.c:1388 [inline]\n __se_sys_openat fs/open.c:1383 [inline]\n __x64_sys_openat+0x138/0x170 fs/open.c:1383\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7fb97dd9c819\nCode: 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\nRSP: 002b:00007fb97ec96028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101\nRAX: ffffffffffffffda RBX: 00007fb97e015fa0 RCX: 00007fb97dd9c819\nRDX: 0000000000042041 RSI: 0000200000000700 RDI: ffffffffffffff9c\nRBP: 00007fb97de32c91 R08: 0000000000000000 R09: 0000000000000000\nR10: 000000000000001d R11: 0000000000000246 R12: 0000000000000000\nR13: 00007fb97e016038 R14: 00007fb97e015fa0 R15: 00007fffcac5f5a8\n </TASK>\n\nAllocated by task 5828:\n kasan_save_stack mm/kasan/common.c:57 [inline]\n kasan_save_track+0x3e/0x80 mm/kasan/common.c:78\n poison_kmalloc_redzone mm/kasan/common.c:398 [inline]\n __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415\n kasan_kmalloc include/linux/kasan.h:263 [inline]\n __do_kmalloc_node mm/slub.c:5260 [inline]\n __kmalloc_noprof+0x35c/0x760 mm/slub.c:5272\n kmalloc_noprof include/linux/slab.h:954 [inline]\n tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251\n tomoyo_get_realpath security/tomoyo/file.c:151 [inline]\n tomoyo_path_perm+0x283/0x560 security/tomoyo/file.c:827\n tomoyo_path_symlink+0xab/0xf0 security/tomoyo/tomoyo.c:212\n security_path_symlink+0x16f/0x360 security/security.c:1477\n filename_symlinkat+0x134/0x410 fs/namei.c:5638\n __do_sys_symlink fs/namei.c:5667 [inline]\n __se_sys_symlink+0x4d/0x2b0 fs/namei.c:5663\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nFreed by task 5828:\n kasan_save_stack mm/kasan/common.c:57 [inline]\n kasan_save_track+0x3e/0x80 mm/kasan/common.c:78\n kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584\n poison_slab_object mm/kasan/common.c:253 [inline]\n __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285\n kasan_slab_free include/linux/kasan.h:235 [inline]\n slab_free_hook mm/slub.c:2685 [inline]\n slab_free mm/slub.c:6165 [inline]\n kfree+0x1c1/0x630 mm/slub.c:6483\n tomoyo_realpath_from_path+0x598/0x5d0 security/tomoyo/realpath.c:286\n tomoyo_get_realpath security/tomoyo/file.c:151 [inline]\n tomoyo_path_perm+0x283/0x560 security/tomoyo/file.c:827\n tomoyo_path_symlink+0xab/0xf0 security/tomoyo/tomoyo.c:212\n security_path_symlink+0x16f/0x360 security/security.c:1477\n filename_symlinkat+0x134/0x410 fs/namei.c:5638\n __do_sys_symlink fs/namei.c:5667 [inline]\n __se_sys_symlink+0x4d/0x2b0 fs/namei.c:5663\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nThe buggy address belongs to the object at ffff888109c42000\n which belongs to the cache kmalloc-4k of size 4096\nThe buggy address is located 3088 bytes inside of\n freed 4096-byte region [ffff888109c42000, ffff888109c43000)\n\nThe buggy address belongs to the physical page:\npage: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x109c40\nhead: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0\nflags: 0x17ff00000000040(head|node=0|zone=2|lastcpupid=0x7ff)\npage_type: f5(slab)\nraw: 017ff00000000040 ffff888100042140 dead000000000100 dead000000000122\nraw: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000\nhead: 017ff00000000040 ffff888100042140 dead000000000100 dead000000000122\nhead: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000\nhead: 017ff00000000003 ffffea0004271001 00000000ffffffff 00000000ffffffff\nhead: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008\npage dumped because: kasan: bad access detected\npage_owner tracks the page as allocated\npage last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5828, tgid 5828 (udevd), ts 67573015608, free_ts 47549723112\n set_page_owner include/linux/page_owner.h:32 [inline]\n post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889\n prep_new_page mm/page_alloc.c:1897 [inline]\n get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962\n __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250\n alloc_slab_page mm/slub.c:3292 [inline]\n allocate_slab+0x77/0x660 mm/slub.c:3481\n new_slab mm/slub.c:3539 [inline]\n refill_objects+0x331/0x3c0 mm/slub.c:7175\n refill_sheaf mm/slub.c:2812 [inline]\n __pcs_replace_empty_main+0x2e6/0x730 mm/slub.c:4615\n alloc_from_pcs mm/slub.c:4717 [inline]\n slab_alloc_node mm/slub.c:4851 [inline]\n __do_kmalloc_node mm/slub.c:5259 [inline]\n __kmalloc_noprof+0x474/0x760 mm/slub.c:5272\n kmalloc_noprof include/linux/slab.h:954 [inline]\n tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251\n tomoyo_get_realpath security/tomoyo/file.c:151 [inline]\n tomoyo_path_perm+0x283/0x560 security/tomoyo/file.c:827\n tomoyo_path_symlink+0xab/0xf0 security/tomoyo/tomoyo.c:212\n security_path_symlink+0x16f/0x360 security/security.c:1477\n filename_symlinkat+0x134/0x410 fs/namei.c:5638\n __do_sys_symlink fs/namei.c:5667 [inline]\n __se_sys_symlink+0x4d/0x2b0 fs/namei.c:5663\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\npage last free pid 5718 tgid 5718 stack trace:\n reset_page_owner include/linux/page_owner.h:25 [inline]\n __free_pages_prepare mm/page_alloc.c:1433 [inline]\n __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978\n __slab_free+0x263/0x2b0 mm/slub.c:5573\n qlink_free mm/kasan/quarantine.c:163 [inline]\n qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179\n kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286\n __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350\n kasan_slab_alloc include/linux/kasan.h:253 [inline]\n slab_post_alloc_hook mm/slub.c:4538 [inline]\n slab_alloc_node mm/slub.c:4866 [inline]\n kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4873\n alloc_filename fs/namei.c:142 [inline]\n do_getname+0x2e/0x250 fs/namei.c:182\n getname include/linux/fs.h:2512 [inline]\n getname_maybe_null include/linux/fs.h:2519 [inline]\n class_filename_maybe_null_constructor include/linux/fs.h:2543 [inline]\n vfs_fstatat+0x45/0x170 fs/stat.c:368\n __do_sys_newfstatat fs/stat.c:538 [inline]\n __se_sys_newfstatat fs/stat.c:532 [inline]\n __x64_sys_newfstatat+0x151/0x200 fs/stat.c:532\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nMemory state around the buggy address:\n ffff888109c42b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n ffff888109c42b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n>ffff888109c42c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n                         ^\n ffff888109c42c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n ffff888109c42d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n==================================================================\n\n\n***\n\nKASAN: use-after-free Read in __ext4_check_dir_entry\n\ntree:      torvalds\nURL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux\nbase:      70b672833f4025341c11b22c7f83778a5cd611bc\narch:      amd64\ncompiler:  Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8\nconfig:    https://ci.syzbot.org/builds/7b860156-1ca9-441f-b899-ebfb5a09620d/config\nsyz repro: https://ci.syzbot.org/findings/21333690-a422-407b-92c7-9247a0075b74/syz_repro\n\nloop1: lost filesystem error report for type 5 error -117\nEXT4-fs (loop1): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.\n==================================================================\nBUG: KASAN: use-after-free in ext4_dirent_get_data_len fs/ext4/ext4.h:4040 [inline]\nBUG: KASAN: use-after-free in ext4_dir_entry_len fs/ext4/ext4.h:4060 [inline]\nBUG: KASAN: use-after-free in __ext4_check_dir_entry+0x527/0xa70 fs/ext4/dir.c:96\nRead of size 1 at addr ffff88810da3609c by task syz.1.20/5966\n\nCPU: 0 UID: 0 PID: 5966 Comm: syz.1.20 Not tainted syzkaller #0 PREEMPT(full) \nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014\nCall Trace:\n <TASK>\n dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:378 [inline]\n print_report+0xba/0x230 mm/kasan/report.c:482\n kasan_report+0x117/0x150 mm/kasan/report.c:595\n ext4_dirent_get_data_len fs/ext4/ext4.h:4040 [inline]\n ext4_dir_entry_len fs/ext4/ext4.h:4060 [inline]\n __ext4_check_dir_entry+0x527/0xa70 fs/ext4/dir.c:96\n ext4_inlinedir_to_tree+0x6be/0xbf0 fs/ext4/inline.c:1322\n ext4_htree_fill_tree+0x50b/0x1230 fs/ext4/namei.c:1184\n ext4_dx_readdir fs/ext4/dir.c:600 [inline]\n ext4_readdir+0x2f7b/0x3870 fs/ext4/dir.c:146\n iterate_dir+0x399/0x570 fs/readdir.c:108\n __do_sys_getdents64 fs/readdir.c:412 [inline]\n __se_sys_getdents64+0xf1/0x280 fs/readdir.c:397\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7fb82a19c819\nCode: 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\nRSP: 002b:00007fb82b01a028 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9\nRAX: ffffffffffffffda RBX: 00007fb82a415fa0 RCX: 00007fb82a19c819\nRDX: 000000000000ff80 RSI: 9999999999999999 RDI: 0000000000000004\nRBP: 00007fb82a232c91 R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000\nR13: 00007fb82a416038 R14: 00007fb82a415fa0 R15: 00007ffdc30464e8\n </TASK>\n\nThe buggy address belongs to the physical page:\npage: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88810da36000 pfn:0x10da36\nflags: 0x17ff00000000000(node=0|zone=2|lastcpupid=0x7ff)\npage_type: f0(buddy)\nraw: 017ff00000000000 ffffea0004364708 ffffea000436a7c8 0000000000000000\nraw: ffff88810da36000 0000000000000000 00000000f0000000 0000000000000000\npage dumped because: kasan: bad access detected\npage_owner tracks the page as freed\npage last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2c00(GFP_NOIO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 15037633903, free_ts 26770192426\n set_page_owner include/linux/page_owner.h:32 [inline]\n post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889\n prep_new_page mm/page_alloc.c:1897 [inline]\n get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962\n __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250\n alloc_slab_page mm/slub.c:3292 [inline]\n allocate_slab+0x77/0x660 mm/slub.c:3481\n new_slab mm/slub.c:3539 [inline]\n refill_objects+0x331/0x3c0 mm/slub.c:7175\n refill_sheaf mm/slub.c:2812 [inline]\n __pcs_replace_empty_main+0x2e6/0x730 mm/slub.c:4615\n alloc_from_pcs mm/slub.c:4717 [inline]\n slab_alloc_node mm/slub.c:4851 [inline]\n __do_kmalloc_node mm/slub.c:5259 [inline]\n __kmalloc_noprof+0x474/0x760 mm/slub.c:5272\n kmalloc_noprof include/linux/slab.h:954 [inline]\n usb_alloc_urb+0x46/0x150 drivers/usb/core/urb.c:75\n usb_internal_control_msg drivers/usb/core/message.c:110 [inline]\n usb_control_msg+0x118/0x3e0 drivers/usb/core/message.c:167\n usb_get_descriptor+0xb1/0x3e0 drivers/usb/core/message.c:852\n usb_get_configuration+0x3b9/0x54f0 drivers/usb/core/config.c:986\n usb_enumerate_device drivers/usb/core/hub.c:2527 [inline]\n usb_new_device+0x145/0x16f0 drivers/usb/core/hub.c:2665\n register_root_hub+0x270/0x5f0 drivers/usb/core/hcd.c:990\n usb_add_hcd+0xba1/0x10b0 drivers/usb/core/hcd.c:2987\n vhci_hcd_probe+0x1fa/0x3e0 drivers/usb/usbip/vhci_hcd.c:1401\n platform_probe+0xf9/0x190 drivers/base/platform.c:1418\npage last free pid 5262 tgid 5262 stack trace:\n reset_page_owner include/linux/page_owner.h:25 [inline]\n __free_pages_prepare mm/page_alloc.c:1433 [inline]\n __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978\n __slab_free+0x263/0x2b0 mm/slub.c:5573\n qlink_free mm/kasan/quarantine.c:163 [inline]\n qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179\n kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286\n __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350\n kasan_slab_alloc include/linux/kasan.h:253 [inline]\n slab_post_alloc_hook mm/slub.c:4538 [inline]\n slab_alloc_node mm/slub.c:4866 [inline]\n kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4873\n alloc_empty_file+0x55/0x1d0 fs/file_table.c:237\n path_openat+0x10f/0x3860 fs/namei.c:4816\n do_file_open+0x23e/0x4a0 fs/namei.c:4859\n do_sys_openat2+0x113/0x200 fs/open.c:1366\n do_sys_open fs/open.c:1372 [inline]\n __do_sys_openat fs/open.c:1388 [inline]\n __se_sys_openat fs/open.c:1383 [inline]\n __x64_sys_openat+0x138/0x170 fs/open.c:1383\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nMemory state around the buggy address:\n ffff88810da35f80: 00 00 00 00 00 00 00 04 fc fc fc fc fc fc fc fc\n ffff88810da36000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n>ffff88810da36080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n                            ^\n ffff88810da36100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n ffff88810da36180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n==================================================================\n\n\n***\n\nIf these findings have caused you to resend the series or submit a\nseparate fix, please add the following tag to your commit message:\n  Tested-by: syzbot@syzkaller.appspotmail.com\n\n---\nThis report is generated by a bot. It may contain errors.\nsyzbot ci engineers can be reached at syzkaller@googlegroups.com.\n\nTo test a patch for this bug, please reply with `#syz test`\n(should be on a separate line).\n\nThe patch should be attached to the email.\nNote: arguments like custom git repos and branches are not supported.","headers":{"Return-Path":"\n <SRS0=gjAC=CR=vger.kernel.org=linux-ext4+bounces-15893-patchwork-incoming=ozlabs.org@ozlabs.org>","X-Original-To":["incoming@patchwork.ozlabs.org","linux-ext4@vger.kernel.org"],"Delivered-To":["patchwork-incoming@legolas.ozlabs.org","patchwork-incoming@ozlabs.org"],"Authentication-Results":["legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=ozlabs.org\n (client-ip=150.107.74.76; helo=mail.ozlabs.org;\n envelope-from=srs0=gjac=cr=vger.kernel.org=linux-ext4+bounces-15893-patchwork-incoming=ozlabs.org@ozlabs.org;\n receiver=patchwork.ozlabs.org)","gandalf.ozlabs.org;\n arc=pass smtp.remote-ip=172.234.253.10 arc.chain=subspace.kernel.org","gandalf.ozlabs.org;\n dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com","gandalf.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=172.234.253.10; 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