syzbot


KASAN: slab-use-after-free Read in btrfs_find_actor

Status: auto-obsoleted due to no activity on 2023/11/07 20:53
Subsystems: btrfs
[Documentation on labels]
Reported-by: syzbot+b746c217b98f77fc0061@syzkaller.appspotmail.com
First crash: 320d, last: 320d

Sample crash report:
BTRFS info (device loop3): enabling ssd optimizations
==================================================================
BUG: KASAN: slab-use-after-free in btrfs_find_actor+0xd5/0x100 fs/btrfs/inode.c:5473
Read of size 8 at addr ffff8880312da2f8 by task syz-executor.3/30312

CPU: 1 PID: 30312 Comm: syz-executor.3 Not tainted 6.5.0-next-20230908-syzkaller #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+0xd9/0x1b0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xc4/0x620 mm/kasan/report.c:475
 kasan_report+0xda/0x110 mm/kasan/report.c:588
 btrfs_find_actor+0xd5/0x100 fs/btrfs/inode.c:5473
 find_inode+0xd5/0x1e0 fs/inode.c:901
 ilookup5_nowait fs/inode.c:1456 [inline]
 ilookup5+0xad/0x210 fs/inode.c:1485
 iget5_locked+0x37/0xe0 fs/inode.c:1266
 btrfs_iget_locked fs/btrfs/inode.c:5487 [inline]
 btrfs_iget_path fs/btrfs/inode.c:5504 [inline]
 btrfs_iget+0xfb/0x220 fs/btrfs/inode.c:5533
 btrfs_fill_super fs/btrfs/super.c:1166 [inline]
 btrfs_mount_root+0xae0/0xdd0 fs/btrfs/super.c:1525
 legacy_get_tree+0x109/0x220 fs/fs_context.c:638
 vfs_get_tree+0x8c/0x370 fs/super.c:1750
 fc_mount fs/namespace.c:1112 [inline]
 vfs_kern_mount.part.0+0xcb/0x170 fs/namespace.c:1142
 vfs_kern_mount+0x3f/0x60 fs/namespace.c:1129
 btrfs_mount+0x292/0xb10 fs/btrfs/super.c:1585
 legacy_get_tree+0x109/0x220 fs/fs_context.c:638
 vfs_get_tree+0x8c/0x370 fs/super.c:1750
 do_new_mount fs/namespace.c:3335 [inline]
 path_mount+0x1492/0x1ed0 fs/namespace.c:3662
 do_mount fs/namespace.c:3675 [inline]
 __do_sys_mount fs/namespace.c:3884 [inline]
 __se_sys_mount fs/namespace.c:3861 [inline]
 __x64_sys_mount+0x293/0x310 fs/namespace.c:3861
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f8fb127e1ea
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 09 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8fafdfdee8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f8fafdfdf80 RCX: 00007f8fb127e1ea
RDX: 00000000200055c0 RSI: 0000000020005600 RDI: 00007f8fafdfdf40
RBP: 00000000200055c0 R08: 00007f8fafdfdf80 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020005600
R13: 00007f8fafdfdf40 R14: 000000000000559d R15: 0000000020000440
 </TASK>

Allocated by task 13395:
 kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 __kasan_slab_alloc+0x81/0x90 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook mm/slab.h:762 [inline]
 slab_alloc_node mm/slub.c:3478 [inline]
 slab_alloc mm/slub.c:3486 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3493 [inline]
 kmem_cache_alloc_lru+0x21a/0x630 mm/slub.c:3509
 alloc_inode_sb include/linux/fs.h:2909 [inline]
 ntfs_alloc_inode+0x25/0x70 fs/ntfs3/super.c:546
 alloc_inode+0x5d/0x220 fs/inode.c:259
 iget5_locked fs/inode.c:1269 [inline]
 iget5_locked+0x63/0xe0 fs/inode.c:1262
 ntfs_iget5+0xd6/0x3960 fs/ntfs3/inode.c:525
 dir_search_u+0x162/0x3d0 fs/ntfs3/dir.c:264
 ntfs_atomic_open+0x3df/0x650 fs/ntfs3/namei.c:400
 atomic_open fs/namei.c:3358 [inline]
 lookup_open.isra.0+0xc44/0x1360 fs/namei.c:3466
 open_last_lookups fs/namei.c:3563 [inline]
 path_openat+0x931/0x29c0 fs/namei.c:3793
 do_filp_open+0x1de/0x430 fs/namei.c:3823
 do_sys_openat2+0x176/0x1e0 fs/open.c:1422
 do_sys_open fs/open.c:1437 [inline]
 __do_sys_openat fs/open.c:1453 [inline]
 __se_sys_openat fs/open.c:1448 [inline]
 __x64_sys_openat+0x175/0x210 fs/open.c:1448
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Last potentially related work creation:
 kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:492
 __call_rcu_common.constprop.0+0x9a/0x790 kernel/rcu/tree.c:2653
 destroy_inode+0x129/0x1b0 fs/inode.c:314
 dispose_list+0x117/0x1e0 fs/inode.c:697
 evict_inodes+0x34f/0x450 fs/inode.c:747
 generic_shutdown_super+0xb5/0x3c0 fs/super.c:672
 kill_block_super+0x3b/0x70 fs/super.c:1646
 ntfs3_kill_sb+0x3f/0xf0 fs/ntfs3/super.c:1727
 deactivate_locked_super+0x9a/0x170 fs/super.c:481
 deactivate_super+0xde/0x100 fs/super.c:514
 cleanup_mnt+0x222/0x3d0 fs/namespace.c:1254
 task_work_run+0x14d/0x240 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x210/0x240 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x1d/0x60 kernel/entry/common.c:296
 do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Second to last potentially related work creation:
 kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:492
 __call_rcu_common.constprop.0+0x9a/0x790 kernel/rcu/tree.c:2653
 destroy_inode+0x129/0x1b0 fs/inode.c:314
 iput_final fs/inode.c:1775 [inline]
 iput.part.0+0x55e/0x7a0 fs/inode.c:1801
 iput+0x5c/0x80 fs/inode.c:1791
 ntfs_loadlog_and_replay+0x1c1/0x5e0 fs/ntfs3/fsntfs.c:326
 ntfs_fill_super+0x265f/0x4330 fs/ntfs3/super.c:1222
 get_tree_bdev+0x3b5/0x650 fs/super.c:1577
 vfs_get_tree+0x8c/0x370 fs/super.c:1750
 do_new_mount fs/namespace.c:3335 [inline]
 path_mount+0x1492/0x1ed0 fs/namespace.c:3662
 do_mount fs/namespace.c:3675 [inline]
 __do_sys_mount fs/namespace.c:3884 [inline]
 __se_sys_mount fs/namespace.c:3861 [inline]
 __x64_sys_mount+0x293/0x310 fs/namespace.c:3861
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

The buggy address belongs to the object at ffff8880312d9d80
 which belongs to the cache ntfs_inode_cache of size 1760
The buggy address is located 1400 bytes inside of
 freed 1760-byte region [ffff8880312d9d80, ffff8880312da460)

The buggy address belongs to the physical page:
page:ffffea0000c4b600 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880312dac40 pfn:0x312d8
head:ffffea0000c4b600 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88801fcffc01
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888014f37a00 ffffea0001dc2800 0000000000000002
raw: ffff8880312dac40 0000000080110005 00000001ffffffff ffff88801fcffc01
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Reclaimable, gfp_mask 0x1d2050(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_RECLAIMABLE), pid 6686, tgid 6684 (syz-executor.1), ts 292401983307, free_ts 0
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x2cf/0x340 mm/page_alloc.c:1530
 prep_new_page mm/page_alloc.c:1537 [inline]
 get_page_from_freelist+0xf17/0x2e50 mm/page_alloc.c:3200
 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4456
 alloc_pages+0x1a9/0x270 mm/mempolicy.c:2298
 alloc_slab_page mm/slub.c:1870 [inline]
 allocate_slab+0x251/0x380 mm/slub.c:2017
 new_slab mm/slub.c:2070 [inline]
 ___slab_alloc+0x8be/0x1570 mm/slub.c:3223
 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322
 __slab_alloc_node mm/slub.c:3375 [inline]
 slab_alloc_node mm/slub.c:3468 [inline]
 slab_alloc mm/slub.c:3486 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3493 [inline]
 kmem_cache_alloc_lru+0x4e4/0x630 mm/slub.c:3509
 alloc_inode_sb include/linux/fs.h:2909 [inline]
 ntfs_alloc_inode+0x25/0x70 fs/ntfs3/super.c:546
 alloc_inode+0x5d/0x220 fs/inode.c:259
 iget5_locked fs/inode.c:1269 [inline]
 iget5_locked+0x63/0xe0 fs/inode.c:1262
 ntfs_iget5+0xd6/0x3960 fs/ntfs3/inode.c:525
 ntfs_loadlog_and_replay+0x130/0x5e0 fs/ntfs3/fsntfs.c:297
 ntfs_fill_super+0x265f/0x4330 fs/ntfs3/super.c:1222
 get_tree_bdev+0x3b5/0x650 fs/super.c:1577
 vfs_get_tree+0x8c/0x370 fs/super.c:1750
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8880312da180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880312da200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880312da280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                                ^
 ffff8880312da300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880312da380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/09/08 20:53 linux-next af3c30d33476 6654cf89 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in btrfs_find_actor
* Struck through repros no longer work on HEAD.