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KASAN: use-after-free Read in bkey_packed_valid

Status: auto-obsoleted due to no activity on 2025/06/06 15:25
Subsystems: bcachefs
[Documentation on labels]
Reported-by: syzbot+5970f72a85a751ab7556@syzkaller.appspotmail.com
First crash: 327d, last: 240d
Cause bisection: introduced by (bisect log) :
commit 03ef80b469d5d83530ce1ce15be78a40e5300f9b
Author: Kent Overstreet <kent.overstreet@linux.dev>
Date: Sat Sep 23 22:41:51 2023 +0000

  bcachefs: Ignore unknown mount options

Crash: invalid opcode in bch2_dump_bset (log)
Repro: C syz .config
  
Fix bisection: the issue occurs on the latest tested release (bisect log)
  
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [bcachefs?] KASAN: use-after-free Read in bkey_packed_valid 0 (3) 2024/12/19 09:45
▶ ▼ Last patch testing requests (10)
Created Duration User Patch Repo Result
2025/06/06 15:04 19m retest repro upstream OK log
2025/04/28 03:15 1h19m retest repro upstream OK log
2025/03/28 08:55 14m retest repro upstream report log
2025/03/22 20:28 19m retest repro upstream OK log
2025/03/22 20:28 22m retest repro upstream OK log
2025/03/22 20:28 21m retest repro upstream OK log
2025/03/22 13:00 21m retest repro upstream OK log
2025/03/22 13:00 21m retest repro upstream OK log
2025/03/22 13:00 21m retest repro upstream OK log
2025/01/17 05:04 16m retest repro upstream report log

Sample crash report:
invalid bkey in btree_node btree=xattrs level=0: u64s 16 type deleted POS_MIN len 0 ver 0: 
  snapshot == 0: delete?, fixing
invalid bkey in btree_node btree=xattrs level=0: u64s 7 type deleted POS_MIN len 0 ver 0: 
  snapshot == 0: delete?, fixing
==================================================================
BUG: KASAN: use-after-free in bkey_packed_valid+0x488/0x6c0 fs/bcachefs/btree_io.c:865
Read of size 1 at addr ffff888045200000 by task kworker/0:1H/41

CPU: 0 UID: 0 PID: 41 Comm: kworker/0:1H Not tainted 6.14.0-rc5-syzkaller-00214-g21e4543a2e2f #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: bcachefs_btree_read_complete btree_node_read_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0x16e/0x5b0 mm/kasan/report.c:521
 kasan_report+0x143/0x180 mm/kasan/report.c:634
 bkey_packed_valid+0x488/0x6c0 fs/bcachefs/btree_io.c:865
 validate_bset_keys+0xeb5/0x1af0 fs/bcachefs/btree_io.c:987
 bch2_btree_node_read_done+0x2298/0x6180 fs/bcachefs/btree_io.c:1164
 btree_node_read_work+0x6dc/0x1380 fs/bcachefs/btree_io.c:1358
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd30 kernel/workqueue.c:3400
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x45200
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
page_type: f0(buddy)
raw: 04fff00000000000 ffffea000114d808 ffff88805ffd7028 0000000000000000
raw: 0000000000000000 0000000000000005 00000000f0000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 5, migratetype Reclaimable, gfp_mask 0x452cd0(GFP_KERNEL_ACCOUNT|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_RECLAIMABLE), pid 5325, tgid 5323 (syz.0.0), ts 69039033713, free_ts 69245104180
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551
 prep_new_page mm/page_alloc.c:1559 [inline]
 get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477
 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4739
 __alloc_pages_noprof+0xa/0x30 mm/page_alloc.c:4773
 __alloc_pages_node_noprof include/linux/gfp.h:265 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:292 [inline]
 ___kmalloc_large_node+0x8b/0x1d0 mm/slub.c:4239
 __kmalloc_large_node_noprof+0x1a/0x80 mm/slub.c:4266
 __do_kmalloc_node mm/slub.c:4282 [inline]
 __kmalloc_node_noprof+0x33a/0x4d0 mm/slub.c:4300
 __kvmalloc_node_noprof+0x72/0x190 mm/util.c:662
 btree_node_data_alloc+0xdb/0x260 fs/bcachefs/btree_cache.c:156
 __bch2_btree_node_mem_alloc+0x201/0x420 fs/bcachefs/btree_cache.c:201
 bch2_fs_btree_cache_init+0x27a/0x630 fs/bcachefs/btree_cache.c:655
 bch2_fs_alloc fs/bcachefs/super.c:919 [inline]
 bch2_fs_open+0x2d2d/0x31e0 fs/bcachefs/super.c:2064
 bch2_fs_get_tree+0x738/0x17a0 fs/bcachefs/fs.c:2190
 vfs_get_tree+0x90/0x2b0 fs/super.c:1814
 do_new_mount+0x2be/0xb40 fs/namespace.c:3560
 do_mount fs/namespace.c:3900 [inline]
 __do_sys_mount fs/namespace.c:4111 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4088
page last free pid 5334 tgid 5334 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 __free_pages_ok+0xbbf/0xe40 mm/page_alloc.c:1271
 __folio_put+0x2b3/0x360 mm/swap.c:112
 folio_put include/linux/mm.h:1489 [inline]
 free_large_kmalloc+0xfe/0x180 mm/slub.c:4728
 kfree+0x212/0x430 mm/slub.c:4751
 btree_bounce_free fs/bcachefs/btree_io.c:111 [inline]
 bch2_btree_node_read_done+0x3c89/0x6180 fs/bcachefs/btree_io.c:1243
 btree_node_read_work+0x6dc/0x1380 fs/bcachefs/btree_io.c:1358
 bch2_btree_node_read+0x2433/0x29f0
 bch2_btree_node_fill+0xca6/0x1370 fs/bcachefs/btree_cache.c:994
 bch2_btree_node_get_noiter+0x9d5/0xf70 fs/bcachefs/btree_cache.c:1261
 found_btree_node_is_readable fs/bcachefs/btree_node_scan.c:84 [inline]
 try_read_btree_node fs/bcachefs/btree_node_scan.c:213 [inline]
 read_btree_nodes_worker+0x1392/0x1fd0 fs/bcachefs/btree_node_scan.c:262
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Memory state around the buggy address:
 ffff8880451fff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880451fff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888045200000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff888045200080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888045200100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Crashes (38):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/03/08 12:32 upstream 21e4543a2e2f 7e3bd60d .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: use-after-free Read in bkey_packed_valid
2025/03/05 05:55 upstream 48a5eed9ad58 c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: use-after-free Read in bkey_packed_valid
2025/03/03 21:29 upstream 7eb172143d55 c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: use-after-free Read in bkey_packed_valid
2025/03/03 18:22 upstream 7eb172143d55 c3901742 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro] ci-snapshot-upstream-root KASAN: use-after-free Read in bkey_packed_valid
2025/03/03 17:53 upstream 7eb172143d55 c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: use-after-free Read in bkey_packed_valid
2025/03/03 13:47 upstream 7eb172143d55 c3901742 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2] ci-snapshot-upstream-root KASAN: use-after-free Read in bkey_packed_valid
2025/01/03 04:11 upstream 0bc21e701a6f d3ccff63 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: use-after-free Read in bkey_packed_valid
2024/12/24 15:49 upstream f07044dd0df0 444551c4 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: use-after-free Read in bkey_packed_valid
2024/12/16 04:45 upstream dccbe2047a5b 7cbfbb3a .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: use-after-free Read in bkey_packed_valid
2024/12/11 09:12 upstream f92f4749861b cfc402b4 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: use-after-free Read in bkey_packed_valid
2025/03/05 23:51 upstream bb2281fb05e5 831e3629 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs KASAN: slab-use-after-free Read in bkey_packed_valid
2025/03/02 22:37 upstream b91872c56940 c3901742 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs KASAN: slab-out-of-bounds Read in bkey_packed_valid
2025/03/02 22:03 upstream b91872c56940 c3901742 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs KASAN: slab-use-after-free Read in bkey_packed_valid
2024/12/22 20:09 upstream bcde95ce32b6 b4fbdbd4 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs KASAN: slab-out-of-bounds Read in bkey_packed_valid
2024/12/18 16:33 upstream aef25be35d23 a0626d3a .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs KASAN: slab-use-after-free Read in bkey_packed_valid
2025/03/05 18:16 upstream cfced12f5100 60f5d8d9 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in bkey_packed_valid
2025/03/05 15:46 upstream 48a5eed9ad58 60f5d8d9 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in bkey_packed_valid
2025/03/05 11:55 upstream 48a5eed9ad58 60f5d8d9 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in bkey_packed_valid
2025/03/05 06:36 upstream 48a5eed9ad58 c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in bkey_packed_valid
2025/03/05 06:20 upstream 48a5eed9ad58 c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in bkey_packed_valid
2025/03/04 16:19 upstream 99fa936e8e4f c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in bkey_packed_valid
2025/03/04 13:59 upstream 99fa936e8e4f c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in bkey_packed_valid
2025/03/04 13:56 upstream 99fa936e8e4f c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in bkey_packed_valid
2025/03/04 09:04 upstream 99fa936e8e4f c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in bkey_packed_valid
2025/03/04 02:13 upstream 99fa936e8e4f c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bkey_packed_valid
2025/03/03 18:24 upstream 7eb172143d55 c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in bkey_packed_valid
2025/03/03 16:20 upstream 7eb172143d55 c3901742 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in bkey_packed_valid
2025/03/03 12:18 upstream 7eb172143d55 c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in bkey_packed_valid
2025/03/03 10:58 upstream 7eb172143d55 c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bkey_packed_valid
2025/03/03 07:40 upstream 1973160c90d7 c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in bkey_packed_valid
2025/03/03 04:18 upstream 1973160c90d7 c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in bkey_packed_valid
2025/03/03 03:09 upstream 1973160c90d7 c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in bkey_packed_valid
2025/03/02 23:31 upstream 1973160c90d7 c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in bkey_packed_valid
2025/03/02 22:18 upstream 1973160c90d7 c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in bkey_packed_valid
2025/03/02 17:51 upstream ece144f151ac c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in bkey_packed_valid
2025/03/02 15:39 upstream ece144f151ac c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in bkey_packed_valid
2025/03/02 15:37 upstream ece144f151ac c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in bkey_packed_valid
2025/03/02 15:36 upstream ece144f151ac c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bkey_packed_valid
* Struck through repros no longer work on HEAD.