Hello, syzbot found the following issue on: HEAD commit: 42f7652d3eb5 Linux 6.12-rc4 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=15a89430580000 kernel config: https://syzkaller.appspot.com/x/.config?x=fc6f8ce8c5369043 dashboard link: https://syzkaller.appspot.com/bug?extid=0c99c3f90699936c1e77 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=162e625f980000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14695c87980000 Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-42f7652d.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/27fd6c638478/vmlinux-42f7652d.xz kernel image: https://storage.googleapis.com/syzbot-assets/a5f529516264/bzImage-42f7652d.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/c97aae4b16ba/mount_0.gz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+0c99c3f90699936c1e77@xxxxxxxxxxxxxxxxxxxxxxxxx EXT4-fs error (device loop0): ext4_orphan_get:1393: comm syz-executor407: couldn't read orphan inode 15 (err -117) EXT4-fs (loop0): mounted filesystem 00000007-0000-0000-0000-000000000000 r/w without journal. Quota mode: none. ================================================================== BUG: KASAN: use-after-free in ext4_insert_dentry+0x36a/0x6d0 fs/ext4/namei.c:2109 Write of size 251 at addr ffff88803f1f7f14 by task syz-executor407/5095 CPU: 0 UID: 0 PID: 5095 Comm: syz-executor407 Not tainted 6.12.0-rc4-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 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 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189 __asan_memcpy+0x40/0x70 mm/kasan/shadow.c:106 ext4_insert_dentry+0x36a/0x6d0 fs/ext4/namei.c:2109 add_dirent_to_buf+0x3d9/0x750 fs/ext4/namei.c:2154 make_indexed_dir+0xf98/0x1600 fs/ext4/namei.c:2351 ext4_add_entry+0x222a/0x25d0 fs/ext4/namei.c:2455 ext4_add_nondir+0x8d/0x290 fs/ext4/namei.c:2796 ext4_symlink+0x920/0xb50 fs/ext4/namei.c:3431 vfs_symlink+0x137/0x2e0 fs/namei.c:4615 do_symlinkat+0x222/0x3a0 fs/namei.c:4641 __do_sys_symlink fs/namei.c:4662 [inline] __se_sys_symlink fs/namei.c:4660 [inline] __x64_sys_symlink+0x7a/0x90 fs/namei.c:4660 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: 0033:0x7fc65cf86b99 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 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:00007ffca8aeb358 EFLAGS: 00000246 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007fc65cf86b99 RDX: 0000000000000000 RSI: 0000000020000cc0 RDI: 0000000020000dc0 RBP: 00007fc65cffa5f0 R08: 00005555889c84c0 R09: 00005555889c84c0 R10: 00005555889c84c0 R11: 0000000000000246 R12: 00007ffca8aeb380 R13: 00007ffca8aeb5a8 R14: 431bde82d7b634db R15: 00007fc65cfcf03b </TASK> The buggy address belongs to the physical page: page: refcount:3 mapcount:0 mapping:ffff888031cb4d78 index:0x3f pfn:0x3f1f7 memcg:ffff888030476000 aops:def_blk_aops ino:700000 dentry name(?):"" flags: 0x4fff08000004214(referenced|dirty|workingset|private|node=1|zone=1|lastcpupid=0x7ff) raw: 04fff08000004214 0000000000000000 dead000000000122 ffff888031cb4d78 raw: 000000000000003f ffff8880454cc658 00000003ffffffff ffff888030476000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Movable, gfp_mask 0x148c48(GFP_NOFS|__GFP_NOFAIL|__GFP_COMP|__GFP_HARDWALL|__GFP_MOVABLE), pid 5095, tgid 5095 (syz-executor407), ts 63020312683, free_ts 62616757387 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+0x3045/0x3190 mm/page_alloc.c:3457 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4733 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 alloc_pages_noprof mm/mempolicy.c:2345 [inline] folio_alloc_noprof+0x128/0x180 mm/mempolicy.c:2352 filemap_alloc_folio_noprof+0xdf/0x500 mm/filemap.c:1010 __filemap_get_folio+0x446/0xbd0 mm/filemap.c:1952 grow_dev_folio fs/buffer.c:1043 [inline] grow_buffers fs/buffer.c:1109 [inline] __getblk_slow fs/buffer.c:1135 [inline] bdev_getblk+0x1d8/0x550 fs/buffer.c:1437 __getblk include/linux/buffer_head.h:380 [inline] sb_getblk include/linux/buffer_head.h:386 [inline] ext4_getblk+0x303/0x800 fs/ext4/inode.c:859 ext4_bread+0x2e/0x180 fs/ext4/inode.c:905 ext4_append+0x327/0x5c0 fs/ext4/namei.c:83 make_indexed_dir+0x523/0x1600 fs/ext4/namei.c:2272 ext4_add_entry+0x222a/0x25d0 fs/ext4/namei.c:2455 ext4_add_nondir+0x8d/0x290 fs/ext4/namei.c:2796 ext4_symlink+0x920/0xb50 fs/ext4/namei.c:3431 vfs_symlink+0x137/0x2e0 fs/namei.c:4615 page last free pid 5089 tgid 5089 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_folios+0xf12/0x18d0 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 vms_clear_ptes+0x437/0x530 mm/vma.c:1096 vms_complete_munmap_vmas+0x208/0x910 mm/vma.c:1140 do_vmi_align_munmap+0x613/0x730 mm/vma.c:1349 do_vmi_munmap+0x24e/0x2d0 mm/vma.c:1397 __vm_munmap+0x24c/0x480 mm/mmap.c:1610 __do_sys_munmap mm/mmap.c:1627 [inline] __se_sys_munmap mm/mmap.c:1624 [inline] __x64_sys_munmap+0x68/0x80 mm/mmap.c:1624 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: ffff88803f1f7f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88803f1f7f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88803f1f8000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88803f1f8080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88803f1f8100: 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. 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
