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KASAN: use-after-free Read in nilfs_segctor_confirm

Status: upstream: reported C repro on 2022/11/18 14:16
Subsystems: nilfs2
[Documentation on labels]
Reported-by: syzbot+09ffbea3b5a1edc48817@syzkaller.appspotmail.com
First crash: 547d, last: 469d
Fix bisection: failed (error log, bisect log)
  
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in nilfs_segctor_confirm nilfs C inconclusive 19 577d 595d 22/26 fixed on 2023/02/24 13:50
linux-4.14 KASAN: use-after-free Read in nilfs_segctor_confirm nilfs2 C 4 460d 545d 0/1 upstream: reported C repro on 2022/11/20 06:43

Sample crash report:
loop0: rw=0, want=7227310118, limit=2048
attempt to access beyond end of device
loop0: rw=0, want=72057594037928010, limit=2048
NILFS (loop0): I/O error reading meta-data file (ino=6, block-offset=1)
==================================================================
BUG: KASAN: use-after-free in nilfs_segctor_confirm+0x15f/0x180 fs/nilfs2/segment.c:839
Read of size 8 at addr ffff8880ab037970 by task syz-executor210/8103

CPU: 1 PID: 8103 Comm: syz-executor210 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354
 kasan_report mm/kasan/report.c:412 [inline]
 __asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433
 nilfs_segctor_confirm+0x15f/0x180 fs/nilfs2/segment.c:839
 nilfs_segctor_destroy fs/nilfs2/segment.c:2726 [inline]
 nilfs_detach_log_writer+0x868/0x9f0 fs/nilfs2/segment.c:2807
 nilfs_put_super+0x3f/0x1a0 fs/nilfs2/super.c:469
 generic_shutdown_super+0x144/0x370 fs/super.c:456
 kill_block_super+0x97/0xf0 fs/super.c:1185
 deactivate_locked_super+0x94/0x160 fs/super.c:329
 deactivate_super+0x174/0x1a0 fs/super.c:360
 cleanup_mnt+0x1a8/0x290 fs/namespace.c:1098
 task_work_run+0x148/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:193 [inline]
 exit_to_usermode_loop+0x251/0x2a0 arch/x86/entry/common.c:167
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fcb5b2acea7
Code: 07 00 48 83 c4 08 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcf11a5b18 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fcb5b2acea7
RDX: 00007ffcf11a5bda RSI: 000000000000000a RDI: 00007ffcf11a5bd0
RBP: 00007ffcf11a5bd0 R08: 00000000ffffffff R09: 00007ffcf11a59b0
R10: 0000555556ce0683 R11: 0000000000000206 R12: 00007ffcf11a6c40
R13: 0000555556ce05f0 R14: 00007ffcf11a5b40 R15: 0000000000000044

Allocated by task 8593:
 kmem_cache_alloc_trace+0x12f/0x380 mm/slab.c:3625
 kmalloc include/linux/slab.h:515 [inline]
 kzalloc include/linux/slab.h:709 [inline]
 nilfs_find_or_create_root+0x84/0x460 fs/nilfs2/the_nilfs.c:752
 nilfs_attach_checkpoint+0xc1/0x4b0 fs/nilfs2/super.c:520
 nilfs_fill_super fs/nilfs2/super.c:1068 [inline]
 nilfs_mount+0xa25/0xe70 fs/nilfs2/super.c:1321
 mount_fs+0xa3/0x310 fs/super.c:1261
 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
 vfs_kern_mount fs/namespace.c:951 [inline]
 do_new_mount fs/namespace.c:2492 [inline]
 do_mount+0x115c/0x2f50 fs/namespace.c:2822
 ksys_mount+0xcf/0x130 fs/namespace.c:3038
 __do_sys_mount fs/namespace.c:3052 [inline]
 __se_sys_mount fs/namespace.c:3049 [inline]
 __x64_sys_mount+0xba/0x150 fs/namespace.c:3049
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 8103:
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcc/0x210 mm/slab.c:3822
 nilfs_put_root+0xb1/0xd0 fs/nilfs2/the_nilfs.c:809
 nilfs_clear_inode+0x1d1/0x240 fs/nilfs2/inode.c:776
 nilfs_evict_inode+0x318/0x440 fs/nilfs2/inode.c:789
 evict+0x2ed/0x760 fs/inode.c:559
 dispose_list+0x124/0x1f0 fs/inode.c:594
 evict_inodes+0x341/0x430 fs/inode.c:644
 generic_shutdown_super+0xb3/0x370 fs/super.c:448
 kill_block_super+0x97/0xf0 fs/super.c:1185
 deactivate_locked_super+0x94/0x160 fs/super.c:329
 deactivate_super+0x174/0x1a0 fs/super.c:360
 cleanup_mnt+0x1a8/0x290 fs/namespace.c:1098
 task_work_run+0x148/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:193 [inline]
 exit_to_usermode_loop+0x251/0x2a0 arch/x86/entry/common.c:167
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8880ab037940
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 48 bytes inside of
 256-byte region [ffff8880ab037940, ffff8880ab037a40)
The buggy address belongs to the page:
page:ffffea0002ac0dc0 count:1 mapcount:0 mapping:ffff88813bff07c0 index:0x0
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffffea0002ac25c8 ffffea0002ac0c88 ffff88813bff07c0
raw: 0000000000000000 ffff8880ab037080 000000010000000c 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880ab037800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880ab037880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880ab037900: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
                                                             ^
 ffff8880ab037980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880ab037a00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/11/18 15:07 linux-4.19.y 3f8a27f9e27b 5bb70014 .config console log report syz C [disk image] [vmlinux] [mounted in repro] ci2-linux-4-19 KASAN: use-after-free Read in nilfs_segctor_confirm
2023/02/04 16:07 linux-4.19.y 3f8a27f9e27b be607b78 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 KASAN: use-after-free Read in nilfs_segctor_confirm
2023/01/16 21:35 linux-4.19.y 3f8a27f9e27b a63719e7 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 KASAN: use-after-free Read in nilfs_segctor_confirm
2023/01/07 01:35 linux-4.19.y 3f8a27f9e27b 1dac8c7a .config console log report info [disk image] [vmlinux] ci2-linux-4-19 KASAN: use-after-free Read in nilfs_segctor_confirm
2022/12/31 21:59 linux-4.19.y 3f8a27f9e27b ab32d508 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 KASAN: use-after-free Read in nilfs_segctor_confirm
2022/12/23 00:07 linux-4.19.y 3f8a27f9e27b 9da18ae8 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 KASAN: use-after-free Read in nilfs_segctor_confirm
2022/12/16 23:16 linux-4.19.y 3f8a27f9e27b 05494336 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 KASAN: use-after-free Read in nilfs_segctor_confirm
2022/11/28 07:05 linux-4.19.y 3f8a27f9e27b f4470a7b .config console log report info [disk image] [vmlinux] ci2-linux-4-19 KASAN: use-after-free Read in nilfs_segctor_confirm
2022/11/18 14:15 linux-4.19.y 3f8a27f9e27b 5bb70014 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 KASAN: use-after-free Read in nilfs_segctor_confirm
* Struck through repros no longer work on HEAD.