syzbot


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

Status: auto-obsoleted due to no activity on 2023/09/21 08:39
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+ada2f14ec3d1638c67d2@syzkaller.appspotmail.com
First crash: 304d, last: 303d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: slab-use-after-free Read in __fput (2) fs C done 6 23d 28d 25/26 upstream: reported C repro on 2024/04/23 11:38

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in d_inode include/linux/dcache.h:516 [inline]
BUG: KASAN: slab-use-after-free in fsnotify_parent include/linux/fsnotify.h:60 [inline]
BUG: KASAN: slab-use-after-free in fsnotify_file include/linux/fsnotify.h:101 [inline]
BUG: KASAN: slab-use-after-free in fsnotify_close include/linux/fsnotify.h:343 [inline]
BUG: KASAN: slab-use-after-free in __fput+0xa1b/0xac0 fs/file_table.c:370
Read of size 8 at addr ffff88808306f4f8 by task syz-executor.0/8670

CPU: 1 PID: 8670 Comm: syz-executor.0 Not tainted 6.5.0-rc2-next-20230721-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023
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
 d_inode include/linux/dcache.h:516 [inline]
 fsnotify_parent include/linux/fsnotify.h:60 [inline]
 fsnotify_file include/linux/fsnotify.h:101 [inline]
 fsnotify_close include/linux/fsnotify.h:343 [inline]
 __fput+0xa1b/0xac0 fs/file_table.c:370
 task_work_run+0x14d/0x240 kernel/task_work.c:179
 get_signal+0x106f/0x27b0 kernel/signal.c:2664
 arch_do_signal_or_restart+0x89/0x5f0 arch/x86/kernel/signal.c:308
 exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
 exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297
 do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7ffb5887cb29
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffb596300c8 EFLAGS: 00000246 ORIG_RAX: 000000000000001c
RAX: ffffffffffffffea RBX: 00007ffb5899bf80 RCX: 00007ffb5887cb29
RDX: 0000000000000019 RSI: 0000000000600003 RDI: 0000000020000000
RBP: 00007ffb588c847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007ffb5899bf80 R15: 00007ffcf7d7b2a8
 </TASK>

Allocated by task 8670:
 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:186 [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
 __d_alloc+0x32/0xac0 fs/dcache.c:1769
 d_alloc_pseudo+0x1c/0x70 fs/dcache.c:1899
 alloc_file_pseudo+0xdc/0x240 fs/file_table.c:329
 __shmem_file_setup mm/shmem.c:4464 [inline]
 __shmem_file_setup+0x1fa/0x2f0 mm/shmem.c:4435
 shmem_kernel_file_setup mm/shmem.c:4483 [inline]
 shmem_zero_setup+0x93/0x1b0 mm/shmem.c:4527
 mmap_region+0x190d/0x2640 mm/mmap.c:2779
 do_mmap+0x87c/0xed0 mm/mmap.c:1353
 vm_mmap_pgoff+0x1a6/0x3b0 mm/util.c:543
 ksys_mmap_pgoff+0x7d/0x5b0 mm/mmap.c:1399
 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

Freed by task 8678:
 kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522
 ____kasan_slab_free mm/kasan/common.c:236 [inline]
 ____kasan_slab_free+0x15e/0x1b0 mm/kasan/common.c:200
 kasan_slab_free include/linux/kasan.h:162 [inline]
 slab_free_hook mm/slub.c:1800 [inline]
 slab_free_freelist_hook+0x114/0x1e0 mm/slub.c:1826
 slab_free mm/slub.c:3809 [inline]
 kmem_cache_free+0xf0/0x490 mm/slub.c:3831
 __d_free fs/dcache.c:298 [inline]
 dentry_free+0xdd/0x160 fs/dcache.c:375
 __dentry_kill+0x4c1/0x640 fs/dcache.c:621
 dentry_kill fs/dcache.c:733 [inline]
 dput+0x8dd/0xfd0 fs/dcache.c:913
 __fput+0x53c/0xac0 fs/file_table.c:392
 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:286 [inline]
 syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297
 do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86
 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
 dentry_free+0xc2/0x160 fs/dcache.c:377
 __dentry_kill+0x4c1/0x640 fs/dcache.c:621
 dentry_kill fs/dcache.c:745 [inline]
 dput+0x703/0xfd0 fs/dcache.c:913
 find_next_child fs/libfs.c:508 [inline]
 simple_recursive_removal+0x13a/0x7d0 fs/libfs.c:523
 debugfs_remove+0x5d/0x80 fs/debugfs/inode.c:764
 kvm_destroy_vm_debugfs+0xc6/0x250 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1012
 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1282 [inline]
 kvm_put_kvm+0x107/0xad0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1347
 kvm_vm_release+0x42/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1370
 __fput+0x3fd/0xac0 fs/file_table.c:384
 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:286 [inline]
 syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297
 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
 dentry_free+0xc2/0x160 fs/dcache.c:377
 __dentry_kill+0x4c1/0x640 fs/dcache.c:621
 dentry_kill fs/dcache.c:745 [inline]
 dput+0x703/0xfd0 fs/dcache.c:913
 do_unlinkat+0x3e9/0x6d0 fs/namei.c:4398
 __do_sys_unlink fs/namei.c:4443 [inline]
 __se_sys_unlink fs/namei.c:4441 [inline]
 __x64_sys_unlink+0xc8/0x110 fs/namei.c:4441
 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 ffff88808306f490
 which belongs to the cache dentry of size 312
The buggy address is located 104 bytes inside of
 freed 312-byte region [ffff88808306f490, ffff88808306f5c8)

The buggy address belongs to the physical page:
page:ffffea00020c1b80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x8306e
head:ffffea00020c1b80 order:1 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff888060610f01
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000010200 ffff8880146758c0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000150015 00000001ffffffff ffff888060610f01
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Reclaimable, gfp_mask 0x1d20d0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_RECLAIMABLE), pid 5336, tgid 5336 (udevd), ts 286140445887, free_ts 261350343305
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x2d2/0x350 mm/page_alloc.c:1569
 prep_new_page mm/page_alloc.c:1576 [inline]
 get_page_from_freelist+0x10d7/0x31b0 mm/page_alloc.c:3256
 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4512
 alloc_pages+0x1a9/0x270 mm/mempolicy.c:2279
 alloc_slab_page mm/slub.c:1870 [inline]
 allocate_slab+0x24e/0x380 mm/slub.c:2017
 new_slab mm/slub.c:2070 [inline]
 ___slab_alloc+0x8bc/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
 __d_alloc+0x32/0xac0 fs/dcache.c:1769
 d_alloc+0x4e/0x220 fs/dcache.c:1849
 lookup_one_qstr_excl+0xc7/0x180 fs/namei.c:1601
 do_unlinkat+0x294/0x6d0 fs/namei.c:4381
 __do_sys_unlink fs/namei.c:4443 [inline]
 __se_sys_unlink fs/namei.c:4441 [inline]
 __x64_sys_unlink+0xc8/0x110 fs/namei.c:4441
 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
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1160 [inline]
 __free_pages_ok+0x6b3/0xef0 mm/page_alloc.c:1299
 kvfree+0x47/0x50 mm/util.c:650
 kmem_free fs/xfs/kmem.h:62 [inline]
 xlog_write_log_records+0x308/0x3e0 fs/xfs/xfs_log_recover.c:1586
 xlog_clear_stale_blocks+0x1fb/0x450 fs/xfs/xfs_log_recover.c:1681
 xlog_find_tail+0x854/0x9d0 fs/xfs/xfs_log_recover.c:1365
 xlog_recover+0x90/0x500 fs/xfs/xfs_log_recover.c:3360
 xfs_log_mount+0x256/0x540 fs/xfs/xfs_log.c:724
 xfs_mountfs+0x10c3/0x1de0 fs/xfs/xfs_mount.c:819
 xfs_fs_fill_super+0x145b/0x1e50 fs/xfs/xfs_super.c:1710
 get_tree_bdev+0x43e/0x7d0 fs/super.c:1318
 vfs_get_tree+0x88/0x350 fs/super.c:1519
 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

Memory state around the buggy address:
 ffff88808306f380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88808306f400: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
>ffff88808306f480: fc fc fa fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                                ^
 ffff88808306f500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88808306f580: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/07/22 13:26 linux-next ae867bc97b71 27cbe77f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in __fput
2023/07/23 08:39 linux-next ae867bc97b71 27cbe77f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __fput
* Struck through repros no longer work on HEAD.