Hello, syzbot found the following issue on: HEAD commit: e32cde8d2bd7 Merge tag 'sched_ext-for-6.12-rc1-fixes-1' of.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=17219927980000 kernel config: https://syzkaller.appspot.com/x/.config?x=1f009dd80b3799c2 dashboard link: https://syzkaller.appspot.com/bug?extid=09921540dd04aba82a35 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=102f23d0580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1082e580580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/08f3ba449e03/disk-e32cde8d.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/17bcace1ab90/vmlinux-e32cde8d.xz kernel image: https://storage.googleapis.com/syzbot-assets/da9183ac0145/bzImage-e32cde8d.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/45cde0725f07/mount_0.gz Bisection is inconclusive: the issue happens on the oldest tested release. bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=14ba5927980000 final oops: https://syzkaller.appspot.com/x/report.txt?x=16ba5927980000 console output: https://syzkaller.appspot.com/x/log.txt?x=12ba5927980000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+09921540dd04aba82a35@xxxxxxxxxxxxxxxxxxxxxxxxx EXT4-fs error (device loop0): ext4_orphan_get:1393: comm syz-executor400: couldn't read orphan inode 15 (err -117) EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none. EXT4-fs warning (device loop0): dx_probe:833: inode #2: comm syz-executor400: Unrecognised inode hash code 4 EXT4-fs warning (device loop0): dx_probe:966: inode #2: comm syz-executor400: Corrupt directory, running e2fsck is recommended ================================================================== BUG: KASAN: use-after-free in __ext4_check_dir_entry+0x6fd/0x880 fs/ext4/dir.c:85 Read of size 2 at addr ffff88807fc17003 by task syz-executor400/5217 CPU: 0 UID: 0 PID: 5217 Comm: syz-executor400 Not tainted 6.12.0-rc1-syzkaller-00031-ge32cde8d2bd7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 __ext4_check_dir_entry+0x6fd/0x880 fs/ext4/dir.c:85 ext4_readdir+0x1436/0x3a60 fs/ext4/dir.c:259 iterate_dir+0x571/0x800 fs/readdir.c:108 __do_sys_getdents64 fs/readdir.c:407 [inline] __se_sys_getdents64+0x1d3/0x4a0 fs/readdir.c:392 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcfd760b6d9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe192a0be8 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 00007ffe192a0bf0 RCX: 00007fcfd760b6d9 RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007ffe192a0bf8 R08: 6c616b7a79732f2e R09: 6c616b7a79732f2e R10: 6c616b7a79732f2e R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe192a0e58 R14: 0000000000000001 R15: 0000000000000001 </TASK> The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x56388aa96 pfn:0x7fc17 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea0001ffe808 ffff8880b8644af0 0000000000000000 raw: 000000056388aa96 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 0, migratetype Movable, gfp_mask 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_COMP|__GFP_ZERO), pid 5214, tgid 5214 (sftp-server), ts 74824128125, free_ts 74900105933 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537 prep_new_page mm/page_alloc.c:1545 [inline] get_page_from_freelist+0x3039/0x3180 mm/page_alloc.c:3457 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4733 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 folio_alloc_mpol_noprof mm/mempolicy.c:2283 [inline] vma_alloc_folio_noprof+0x12e/0x230 mm/mempolicy.c:2314 folio_prealloc+0x31/0x170 alloc_anon_folio mm/memory.c:4721 [inline] do_anonymous_page mm/memory.c:4778 [inline] do_pte_missing mm/memory.c:3963 [inline] handle_pte_fault+0x24dd/0x6800 mm/memory.c:5751 __handle_mm_fault mm/memory.c:5894 [inline] handle_mm_fault+0x1053/0x1ad0 mm/memory.c:6062 do_user_addr_fault arch/x86/mm/fault.c:1338 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x459/0x8c0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 page last free pid 5214 tgid 5214 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_folios+0xee2/0x18a0 mm/page_alloc.c:2686 folios_put_refs+0x76c/0x860 mm/swap.c:1007 free_pages_and_swap_cache+0x2ea/0x690 mm/swap_state.c:332 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline] tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:366 [inline] tlb_flush_mmu+0x3a3/0x680 mm/mmu_gather.c:373 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:465 exit_mmap+0x496/0xc40 mm/mmap.c:1877 __mmput+0x115/0x380 kernel/fork.c:1347 exit_mm+0x220/0x310 kernel/exit.c:571 do_exit+0x9b2/0x28e0 kernel/exit.c:926 do_group_exit+0x207/0x2c0 kernel/exit.c:1088 __do_sys_exit_group kernel/exit.c:1099 [inline] __se_sys_exit_group kernel/exit.c:1097 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1097 x64_sys_call+0x2634/0x2640 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88807fc16f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88807fc16f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88807fc17000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88807fc17080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88807fc17100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
