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Date:   Sat, 12 Aug 2023 03:09:08 -0700
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Subject: [syzbot] [udf?] KASAN: use-after-free Read in udf_sync_fs
From:   syzbot <syzbot+82df44ede2faca24c729@syzkaller.appspotmail.com>
To:     jack@suse.com, linux-fsdevel@vger.kernel.org,
        linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com
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Hello,

syzbot found the following issue on:

HEAD commit:    f8de32cc060b Merge tag 'tpmdd-v6.5-rc7' of git://git.kerne..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=12ac6b63a80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=171b698bc2e613cf
dashboard link: https://syzkaller.appspot.com/bug?extid=82df44ede2faca24c729
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=10df55d7a80000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17e4d78ba80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e92cdc2deca7/disk-f8de32cc.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f821f8a8a452/vmlinux-f8de32cc.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b58fb75b1ad9/bzImage-f8de32cc.xz
mounted in repro #1: https://storage.googleapis.com/syzbot-assets/6f92232ea34d/mount_0.gz
mounted in repro #2: https://storage.googleapis.com/syzbot-assets/9c162574e7a2/mount_2.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+82df44ede2faca24c729@syzkaller.appspotmail.com

         option from the mount to silence this warning.
=======================================================
UDF-fs: INFO Mounting volume 'LinuxUDF', timestamp 2022/11/22 14:59 (1000)
==================================================================
BUG: KASAN: use-after-free in crc_itu_t+0x21c/0x2a0 lib/crc-itu-t.c:60
Read of size 1 at addr ffff88807615a000 by task syz-executor345/5015

CPU: 0 PID: 5015 Comm: syz-executor345 Not tainted 6.5.0-rc5-syzkaller-00296-gf8de32cc060b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0x163/0x540 mm/kasan/report.c:475
 kasan_report+0x175/0x1b0 mm/kasan/report.c:588
 crc_itu_t+0x21c/0x2a0 lib/crc-itu-t.c:60
 udf_finalize_lvid fs/udf/super.c:1984 [inline]
 udf_sync_fs+0x1d2/0x380 fs/udf/super.c:2340
 sync_filesystem+0xec/0x220 fs/sync.c:56
 generic_shutdown_super+0x6f/0x340 fs/super.c:472
 kill_block_super+0x68/0xa0 fs/super.c:1417
 deactivate_locked_super+0xa4/0x110 fs/super.c:330
 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1254
 task_work_run+0x24a/0x300 kernel/task_work.c:179
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0x68f/0x2290 kernel/exit.c:874
 do_group_exit+0x206/0x2c0 kernel/exit.c:1024
 __do_sys_exit_group kernel/exit.c:1035 [inline]
 __se_sys_exit_group kernel/exit.c:1033 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f655d3c5a09
Code: Unable to access opcode bytes at 0x7f655d3c59df.
RSP: 002b:00007ffd9560b9e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f655d3c5a09
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000001
RBP: 00007f655d4612d0 R08: ffffffffffffffb8 R09: 0000000000000004
R10: 0000000000001400 R11: 0000000000000246 R12: 00007f655d4612d0
R13: 0000000000000000 R14: 00007f655d462040 R15: 00007f655d393f30
 </TASK>

The buggy address belongs to the physical page:
page:ffffea0001d85680 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x7615a
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000000 ffffea0001d85408 ffffea0001ce1548 0000000000000000
raw: 0000000000000001 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 4872, tgid 4872 (sshd), ts 47777475140, free_ts 47861737656
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1570
 prep_new_page mm/page_alloc.c:1577 [inline]
 get_page_from_freelist+0x31e8/0x3370 mm/page_alloc.c:3221
 __alloc_pages+0x255/0x670 mm/page_alloc.c:4477
 __folio_alloc+0x13/0x30 mm/page_alloc.c:4509
 vma_alloc_folio+0x48a/0x9a0 mm/mempolicy.c:2253
 do_anonymous_page mm/memory.c:4104 [inline]
 do_pte_missing mm/memory.c:3662 [inline]
 handle_pte_fault mm/memory.c:4939 [inline]
 __handle_mm_fault mm/memory.c:5079 [inline]
 handle_mm_fault+0x20c7/0x5410 mm/memory.c:5233
 do_user_addr_fault arch/x86/mm/fault.c:1343 [inline]
 handle_page_fault arch/x86/mm/fault.c:1486 [inline]
 exc_page_fault+0x3cf/0x7c0 arch/x86/mm/fault.c:1542
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1161 [inline]
 free_unref_page_prepare+0x903/0xa30 mm/page_alloc.c:2348
 free_unref_page_list+0x596/0x830 mm/page_alloc.c:2489
 release_pages+0x2193/0x2470 mm/swap.c:1042
 tlb_batch_pages_flush mm/mmu_gather.c:97 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:292 [inline]
 tlb_flush_mmu+0x100/0x210 mm/mmu_gather.c:299
 tlb_finish_mmu+0xd4/0x1f0 mm/mmu_gather.c:391
 unmap_region+0x258/0x2a0 mm/mmap.c:2318
 do_vmi_align_munmap+0x135d/0x1630 mm/mmap.c:2557
 do_vmi_munmap+0x24d/0x2d0 mm/mmap.c:2624
 __vm_munmap+0x230/0x450 mm/mmap.c:2906
 __do_sys_munmap mm/mmap.c:2923 [inline]
 __se_sys_munmap mm/mmap.c:2920 [inline]
 __x64_sys_munmap+0x69/0x80 mm/mmap.c:2920
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
 ffff888076159f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888076159f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88807615a000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff88807615a080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88807615a100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================


---
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