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

Status: fixed on 2024/08/14 03:44
Subsystems: f2fs
[Documentation on labels]
Reported-by: syzbot+74ebe2104433e9dc610d@syzkaller.appspotmail.com
Fix commit: d7409b05a64f f2fs: fix to cover read extent cache access with lock
First crash: 815d, last: 772d
Cause bisection: introduced by (bisect log) :
commit a53936361330e4c55c0654605178281387d9c761
Author: Chao Yu <chao@kernel.org>
Date: Sun Dec 10 09:20:35 2023 +0000

  f2fs: delete obsolete FI_FIRST_BLOCK_WRITTEN

Crash: KASAN: slab-use-after-free Read in sanity_check_extent_cache (log)
Repro: C syz .config
  
▶ ▼ Discussions (6)
Title Replies (including bot) Last reply
[PATCH 6.1.y] f2fs: fix to cover read extent cache access with lock 1 (1) 2025/05/09 02:46
[PATCH AUTOSEL 6.6 1/7] f2fs: fix to do sanity check on F2FS_INLINE_DATA flag in inode during GC 4 (4) 2024/07/30 12:45
[PATCH AUTOSEL 6.10 1/7] f2fs: fix to do sanity check on F2FS_INLINE_DATA flag in inode during GC 4 (4) 2024/07/30 12:45
[PATCH v2] f2fs: fix to cover read extent cache access with lock 2 (2) 2024/06/12 15:55
[syzbot] [f2fs?] KASAN: slab-use-after-free Read in sanity_check_extent_cache 2 (6) 2024/05/31 01:58
[PATCH] f2fs: fix to cover read extent cache access with lock 1 (1) 2024/05/29 09:52
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 KASAN: use-after-free Read in sanity_check_extent_cache missing-backport origin:lts-only 19 C inconclusive 4 205d 482d 0/3 upstream: reported C repro on 2025/03/28 08:10
android-6-1 KASAN: use-after-free Read in sanity_check_extent_cache origin:lts 19 C error 3 78d 400d 0/2 upstream: reported C repro on 2025/06/17 23:46
▶ ▼ Last patch testing requests (7)
Created Duration User Patch Repo Result
2024/06/11 17:08 20m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2024/06/11 17:08 20m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2024/05/31 01:39 18m chao@kernel.org https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git wip OK log
2024/05/29 11:26 20m chao@kernel.org https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git wip error
2024/05/28 16:23 12m retest repro upstream report log
2024/05/28 16:23 19m retest repro upstream report log
2024/05/03 11:04 20m chao@kernel.org git://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git bugfix/syzbot OK log

Sample crash report:
RBP: 00007f572cd516f0 R08: 00007fffe4582ab7 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f572cd516fc
R13: 000000000000006e R14: 00007fffe45829d0 R15: 00007fffe4582ab8
 </TASK>
==================================================================
BUG: KASAN: slab-use-after-free in sanity_check_extent_cache+0x370/0x410 fs/f2fs/extent_cache.c:46
Read of size 4 at addr ffff88807ef61080 by task syz-executor714/5089

CPU: 0 PID: 5089 Comm: syz-executor714 Not tainted 6.9.0-rc6-syzkaller-00234-g7367539ad4b0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 sanity_check_extent_cache+0x370/0x410 fs/f2fs/extent_cache.c:46
 do_read_inode fs/f2fs/inode.c:509 [inline]
 f2fs_iget+0x33e1/0x46e0 fs/f2fs/inode.c:560
 f2fs_nfs_get_inode+0x74/0x100 fs/f2fs/super.c:3237
 generic_fh_to_dentry+0x9f/0xf0 fs/libfs.c:1413
 exportfs_decode_fh_raw+0x152/0x5f0 fs/exportfs/expfs.c:444
 exportfs_decode_fh+0x3c/0x80 fs/exportfs/expfs.c:584
 do_handle_to_path fs/fhandle.c:155 [inline]
 handle_to_path fs/fhandle.c:210 [inline]
 do_handle_open+0x495/0x650 fs/fhandle.c:226
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f572ccc9b59
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 1f 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:00007f572cc53168 EFLAGS: 00000246 ORIG_RAX: 0000000000000130
RAX: ffffffffffffffda RBX: 00007f572cd516f8 RCX: 00007f572ccc9b59
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000004
RBP: 00007f572cd516f0 R08: 00007fffe4582ab7 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f572cd516fc
R13: 000000000000006e R14: 00007fffe45829d0 R15: 00007fffe4582ab8
 </TASK>

Allocated by task 5084:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:312 [inline]
 __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3798 [inline]
 slab_alloc_node mm/slub.c:3845 [inline]
 kmem_cache_alloc+0x174/0x340 mm/slub.c:3852
 f2fs_kmem_cache_alloc_nofail fs/f2fs/f2fs.h:2817 [inline]
 f2fs_kmem_cache_alloc fs/f2fs/f2fs.h:2827 [inline]
 __grab_extent_tree+0x183/0x400 fs/f2fs/extent_cache.c:334
 f2fs_init_read_extent_tree+0x455/0x910 fs/f2fs/extent_cache.c:405
 do_read_inode fs/f2fs/inode.c:506 [inline]
 f2fs_iget+0x33d1/0x46e0 fs/f2fs/inode.c:560
 f2fs_nfs_get_inode+0x74/0x100 fs/f2fs/super.c:3237
 generic_fh_to_dentry+0x9f/0xf0 fs/libfs.c:1413
 exportfs_decode_fh_raw+0x152/0x5f0 fs/exportfs/expfs.c:444
 exportfs_decode_fh+0x3c/0x80 fs/exportfs/expfs.c:584
 do_handle_to_path fs/fhandle.c:155 [inline]
 handle_to_path fs/fhandle.c:210 [inline]
 do_handle_open+0x495/0x650 fs/fhandle.c:226
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5084:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object+0xa6/0xe0 mm/kasan/common.c:240
 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2106 [inline]
 slab_free mm/slub.c:4280 [inline]
 kmem_cache_free+0x10b/0x2c0 mm/slub.c:4344
 __destroy_extent_tree+0x307/0x600 fs/f2fs/extent_cache.c:1132
 f2fs_destroy_extent_tree+0x17/0x30 fs/f2fs/extent_cache.c:1143
 f2fs_evict_inode+0x44d/0x1550 fs/f2fs/inode.c:831
 evict+0x2a8/0x630 fs/inode.c:667
 f2fs_iget+0x1a68/0x46e0 fs/f2fs/inode.c:621
 f2fs_nfs_get_inode+0x74/0x100 fs/f2fs/super.c:3237
 generic_fh_to_dentry+0x9f/0xf0 fs/libfs.c:1413
 exportfs_decode_fh_raw+0x152/0x5f0 fs/exportfs/expfs.c:444
 exportfs_decode_fh+0x3c/0x80 fs/exportfs/expfs.c:584
 do_handle_to_path fs/fhandle.c:155 [inline]
 handle_to_path fs/fhandle.c:210 [inline]
 do_handle_open+0x495/0x650 fs/fhandle.c:226
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88807ef61000
 which belongs to the cache f2fs_extent_tree of size 144
The buggy address is located 128 bytes inside of
 freed 144-byte region [ffff88807ef61000, ffff88807ef61090)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7ef61
flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000800 ffff88801bbfdc80 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080130013 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Reclaimable, gfp_mask 0x12c50(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_RECLAIMABLE), pid 5073, tgid -147224205 (syz-executor714), ts 5084, free_ts 17531897574
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1534
 prep_new_page mm/page_alloc.c:1541 [inline]
 get_page_from_freelist+0x3410/0x35b0 mm/page_alloc.c:3317
 __alloc_pages+0x256/0x6c0 mm/page_alloc.c:4575
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 alloc_slab_page+0x5f/0x160 mm/slub.c:2175
 allocate_slab mm/slub.c:2338 [inline]
 new_slab+0x84/0x2f0 mm/slub.c:2391
 ___slab_alloc+0xc73/0x1260 mm/slub.c:3525
 __slab_alloc mm/slub.c:3610 [inline]
 __slab_alloc_node mm/slub.c:3663 [inline]
 slab_alloc_node mm/slub.c:3835 [inline]
 kmem_cache_alloc+0x252/0x340 mm/slub.c:3852
 f2fs_kmem_cache_alloc_nofail fs/f2fs/f2fs.h:2817 [inline]
 f2fs_kmem_cache_alloc fs/f2fs/f2fs.h:2827 [inline]
 __grab_extent_tree+0x183/0x400 fs/f2fs/extent_cache.c:334
 f2fs_init_read_extent_tree+0x455/0x910 fs/f2fs/extent_cache.c:405
 do_read_inode fs/f2fs/inode.c:506 [inline]
 f2fs_iget+0x33d1/0x46e0 fs/f2fs/inode.c:560
 f2fs_nfs_get_inode+0x74/0x100 fs/f2fs/super.c:3237
 generic_fh_to_dentry+0x9f/0xf0 fs/libfs.c:1413
 exportfs_decode_fh_raw+0x152/0x5f0 fs/exportfs/expfs.c:444
 exportfs_decode_fh+0x3c/0x80 fs/exportfs/expfs.c:584
 do_handle_to_path fs/fhandle.c:155 [inline]
 handle_to_path fs/fhandle.c:210 [inline]
 do_handle_open+0x495/0x650 fs/fhandle.c:226
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
page last free pid 1 tgid 1 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1141 [inline]
 free_unref_page_prepare+0x97b/0xaa0 mm/page_alloc.c:2347
 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2487
 free_contig_range+0x9e/0x160 mm/page_alloc.c:6572
 destroy_args+0x8a/0x890 mm/debug_vm_pgtable.c:1036
 debug_vm_pgtable+0x4be/0x550 mm/debug_vm_pgtable.c:1416
 do_one_initcall+0x248/0x880 init/main.c:1245
 do_initcall_level+0x157/0x210 init/main.c:1307
 do_initcalls+0x3f/0x80 init/main.c:1323
 kernel_init_freeable+0x435/0x5d0 init/main.c:1555
 kernel_init+0x1d/0x2b0 init/main.c:1444
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Memory state around the buggy address:
 ffff88807ef60f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88807ef61000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807ef61080: fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff88807ef61100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88807ef61180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/05 17:18 upstream 7367539ad4b0 610f2a54 .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs KASAN: slab-use-after-free Read in sanity_check_extent_cache
2024/04/29 02:20 upstream e67572cd2204 07b455f9 .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs KASAN: slab-use-after-free Read in sanity_check_extent_cache
2024/05/14 13:49 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fda5695d692c fdb4c10c .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-gce-arm64 KASAN: slab-use-after-free Read in sanity_check_extent_cache
2024/04/29 01:08 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 6a71d2909427 07b455f9 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-gce-arm64 KASAN: slab-use-after-free Read in sanity_check_extent_cache
2024/04/29 00:38 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 6a71d2909427 07b455f9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 KASAN: slab-use-after-free Read in sanity_check_extent_cache
* Struck through repros no longer work on HEAD.