syzbot


KASAN: use-after-free Read in f2fs_write_end_io

Status: upstream: reported on 2022/08/16 08:08
Reported-by: syzbot+1a52906c5f8683d9c085@syzkaller.appspotmail.com
First crash: 56d, last: 56d

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in instrument_atomic_read include/linux/instrumented.h:71 [inline]
BUG: KASAN: use-after-free in atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline]
BUG: KASAN: use-after-free in get_pages fs/f2fs/f2fs.h:2423 [inline]
BUG: KASAN: use-after-free in f2fs_write_end_io+0x141/0x12a0 fs/f2fs/data.c:348
Read of size 4 at addr ffff8880752b4e58 by task ksoftirqd/1/23

CPU: 1 PID: 23 Comm: ksoftirqd/1 Not tainted 5.19.0-syzkaller-02972-g200e340f2196 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description.constprop.0.cold+0xeb/0x495 mm/kasan/report.c:313
 print_report mm/kasan/report.c:429 [inline]
 kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491
 check_region_inline mm/kasan/generic.c:183 [inline]
 kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline]
 get_pages fs/f2fs/f2fs.h:2423 [inline]
 f2fs_write_end_io+0x141/0x12a0 fs/f2fs/data.c:348
 bio_endio+0x5fe/0x780 block/bio.c:1562
 req_bio_endio block/blk-mq.c:695 [inline]
 blk_update_request+0x401/0x1310 block/blk-mq.c:825
 blk_mq_end_request+0x4b/0x80 block/blk-mq.c:951
 blk_flush_complete_seq+0x561/0xfd0 block/blk-flush.c:211
 flush_end_io+0x77a/0xc60 block/blk-flush.c:268
 __blk_mq_end_request+0x123/0x580 block/blk-mq.c:942
 lo_complete_rq+0x1c2/0x280 drivers/block/loop.c:370
 blk_complete_reqs+0xad/0xe0 block/blk-mq.c:1022
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:571
 run_ksoftirqd kernel/softirq.c:934 [inline]
 run_ksoftirqd+0x2d/0x60 kernel/softirq.c:926
 smpboot_thread_fn+0x645/0x9c0 kernel/smpboot.c:164
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>

Allocated by task 16300:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:437 [inline]
 ____kasan_kmalloc mm/kasan/common.c:516 [inline]
 ____kasan_kmalloc mm/kasan/common.c:475 [inline]
 __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:525
 kmalloc include/linux/slab.h:600 [inline]
 kzalloc include/linux/slab.h:733 [inline]
 f2fs_fill_super+0xf9/0x75d0 fs/f2fs/super.c:3999
 mount_bdev+0x34d/0x410 fs/super.c:1367
 legacy_get_tree+0x105/0x220 fs/fs_context.c:610
 vfs_get_tree+0x89/0x2f0 fs/super.c:1497
 do_new_mount fs/namespace.c:3040 [inline]
 path_mount+0x1320/0x1fa0 fs/namespace.c:3370
 do_mount fs/namespace.c:3383 [inline]
 __do_sys_mount fs/namespace.c:3591 [inline]
 __se_sys_mount fs/namespace.c:3568 [inline]
 __ia32_sys_mount+0x27e/0x300 fs/namespace.c:3568
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203
 entry_SYSENTER_compat_after_hwframe+0x70/0x82

Freed by task 3896:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track+0x21/0x30 mm/kasan/common.c:45
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
 ____kasan_slab_free mm/kasan/common.c:367 [inline]
 ____kasan_slab_free+0x166/0x1a0 mm/kasan/common.c:329
 kasan_slab_free include/linux/kasan.h:200 [inline]
 slab_free_hook mm/slub.c:1754 [inline]
 slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1780
 slab_free mm/slub.c:3534 [inline]
 kfree+0xe2/0x4d0 mm/slub.c:4562
 f2fs_put_super+0x7d4/0xc10 fs/f2fs/super.c:1603
 generic_shutdown_super+0x14c/0x400 fs/super.c:462
 kill_block_super+0x97/0xf0 fs/super.c:1394
 kill_f2fs_super+0x2b3/0x3c0 fs/f2fs/super.c:4516
 deactivate_locked_super+0x94/0x160 fs/super.c:332
 deactivate_super+0xad/0xd0 fs/super.c:363
 cleanup_mnt+0x3a2/0x540 fs/namespace.c:1186
 task_work_run+0xdd/0x1a0 kernel/task_work.c:177
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:169 [inline]
 exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294
 __do_fast_syscall_32+0x72/0xf0 arch/x86/entry/common.c:181
 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203
 entry_SYSENTER_compat_after_hwframe+0x70/0x82

The buggy address belongs to the object at ffff8880752b4000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 3672 bytes inside of
 8192-byte region [ffff8880752b4000, ffff8880752b6000)

The buggy address belongs to the physical page:
page:ffffea0001d4ac00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x752b0
head:ffffea0001d4ac00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4fff00000010200(slab|head|node=1|zone=1|lastcpupid=0x7ff)
raw: 04fff00000010200 ffffea0000864200 dead000000000002 ffff888011843180
raw: 0000000000000000 0000000080020002 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 15655, tgid 15654 (syz-executor.0), ts 723661245241, free_ts 723629165352
 prep_new_page mm/page_alloc.c:2457 [inline]
 get_page_from_freelist+0x1298/0x3b80 mm/page_alloc.c:4203
 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5431
 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2272
 alloc_slab_page mm/slub.c:1824 [inline]
 allocate_slab+0x26c/0x3c0 mm/slub.c:1969
 new_slab mm/slub.c:2029 [inline]
 ___slab_alloc+0x99f/0xe10 mm/slub.c:3031
 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3118
 slab_alloc_node mm/slub.c:3209 [inline]
 slab_alloc mm/slub.c:3251 [inline]
 __kmalloc_track_caller+0x36f/0x450 mm/slub.c:4924
 copy_array+0xc5/0xe0 kernel/bpf/verifier.c:991
 copy_stack_state kernel/bpf/verifier.c:1037 [inline]
 copy_func_state kernel/bpf/verifier.c:1154 [inline]
 copy_verifier_state+0x71e/0xb80 kernel/bpf/verifier.c:1190
 is_state_visited kernel/bpf/verifier.c:11876 [inline]
 do_check kernel/bpf/verifier.c:11991 [inline]
 do_check_common+0x19f5/0xd010 kernel/bpf/verifier.c:14371
 do_check_main kernel/bpf/verifier.c:14434 [inline]
 bpf_check+0x8538/0xb680 kernel/bpf/verifier.c:15003
 bpf_prog_load+0xfb2/0x2250 kernel/bpf/syscall.c:2575
 __sys_bpf+0x11a1/0x5700 kernel/bpf/syscall.c:4917
 __do_sys_bpf kernel/bpf/syscall.c:5021 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5019 [inline]
 __ia32_sys_bpf+0x74/0xc0 kernel/bpf/syscall.c:5019
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1371 [inline]
 free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1421
 free_unref_page_prepare mm/page_alloc.c:3344 [inline]
 free_unref_page+0x19/0x6a0 mm/page_alloc.c:3439
 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2548
 qlink_free mm/kasan/quarantine.c:168 [inline]
 qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294
 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:447
 kasan_slab_alloc include/linux/kasan.h:224 [inline]
 slab_post_alloc_hook mm/slab.h:727 [inline]
 slab_alloc_node mm/slub.c:3243 [inline]
 slab_alloc mm/slub.c:3251 [inline]
 kmem_cache_alloc_trace+0x271/0x3f0 mm/slub.c:3282
 kmalloc include/linux/slab.h:600 [inline]
 kzalloc include/linux/slab.h:733 [inline]
 kernfs_fop_open+0x317/0xda0 fs/kernfs/file.c:621
 do_dentry_open+0x4a1/0x12d0 fs/open.c:878
 do_open fs/namei.c:3499 [inline]
 path_openat+0x1c92/0x28f0 fs/namei.c:3632
 do_filp_open+0x1b6/0x400 fs/namei.c:3659
 do_sys_openat2+0x16d/0x4c0 fs/open.c:1310
 do_sys_open fs/open.c:1326 [inline]
 __do_sys_openat fs/open.c:1342 [inline]
 __se_sys_openat fs/open.c:1337 [inline]
 __x64_sys_openat+0x13f/0x1f0 fs/open.c:1337
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
 ffff8880752b4d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880752b4d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880752b4e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff8880752b4e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880752b4f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-qemu-upstream-386 2022/08/08 18:50 upstream 200e340f2196 da700653 .config log report info KASAN: use-after-free Read in f2fs_write_end_io
* Struck through repros no longer work on HEAD.