syzbot


UBSAN: shift-out-of-bounds in __bch2_bkey_invalid

Status: fixed on 2024/06/05 13:52
Subsystems: bcachefs
[Documentation on labels]
Reported-by: syzbot+ae4dc916da3ce51f284f@syzkaller.appspotmail.com
Fix commit: 2bb9600d5d47 bcachefs: Guard against unknown k.k->type in __bkey_invalid()
First crash: 78d, last: 52d
Cause bisection: introduced by (bisect log) :
commit d789e9a7d5e2799f4d5425b0b620210d2fcad529
Author: Kent Overstreet <kent.overstreet@linux.dev>
Date: Sun Apr 14 03:59:28 2024 +0000

  bcachefs: Interior known are required to have known key types

Crash: UBSAN: shift-out-of-bounds in __bch2_bkey_invalid (log)
Repro: C syz .config
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [bcachefs?] UBSAN: shift-out-of-bounds in __bch2_bkey_invalid 0 (2) 2024/05/06 09:36

Sample crash report:
loop0: detected capacity change from 0 to 32768
bcachefs (loop0): mounting version 1.7: mi_btree_bitmap opts=metadata_checksum=none,data_checksum=none,nojournal_transaction_names
------------[ cut here ]------------
UBSAN: shift-out-of-bounds in fs/bcachefs/bkey_methods.c:174:2
shift exponent 255 is too large for 64-bit type 'unsigned long long'
CPU: 0 PID: 5076 Comm: syz-executor289 Not tainted 6.9.0-rc6-syzkaller-00290-gb9158815de52 #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
 ubsan_epilogue lib/ubsan.c:231 [inline]
 __ubsan_handle_shift_out_of_bounds+0x3c8/0x420 lib/ubsan.c:468
 __bch2_bkey_invalid+0x70f/0x740 fs/bcachefs/bkey_methods.c:174
 bch2_bkey_invalid+0x3b/0x200 fs/bcachefs/bkey_methods.c:230
 journal_validate_key+0x73a/0xec0 fs/bcachefs/journal_io.c:344
 journal_entry_btree_root_validate+0x165/0x480 fs/bcachefs/journal_io.c:440
 bch2_sb_clean_validate_late fs/bcachefs/sb-clean.c:40 [inline]
 bch2_read_superblock_clean+0x1b9/0x4c0 fs/bcachefs/sb-clean.c:168
 bch2_fs_recovery+0x1e8/0x6390 fs/bcachefs/recovery.c:573
 bch2_fs_start+0x356/0x5b0 fs/bcachefs/super.c:1043
 bch2_fs_open+0xa8d/0xdf0 fs/bcachefs/super.c:2102
 bch2_mount+0x71d/0x1320 fs/bcachefs/fs.c:1903
 legacy_get_tree+0xee/0x190 fs/fs_context.c:662
 vfs_get_tree+0x90/0x2a0 fs/super.c:1779
 do_new_mount+0x2be/0xb40 fs/namespace.c:3352
 do_mount fs/namespace.c:3692 [inline]
 __do_sys_mount fs/namespace.c:3898 [inline]
 __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3875
 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: 0033:0x7f241b297bba
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 5e 04 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe72e34988 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffe72e349a0 RCX: 00007f241b297bba
RDX: 0000000020011a00 RSI: 0000000020011a40 RDI: 00007ffe72e349a0
RBP: 0000000000000004 R08: 00007ffe72e349e0 R09: 00000000000119f0
R10: 0000000002000002 R11: 0000000000000282 R12: 0000000002000002
R13: 00007ffe72e349e0 R14: 0000000000000003 R15: 0000000001000000
 </TASK>
---[ end trace ]---

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/06 00:22 upstream b9158815de52 610f2a54 .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs UBSAN: shift-out-of-bounds in __bch2_bkey_invalid
2024/05/05 17:22 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 78186bd77b47 610f2a54 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-gce-arm64 UBSAN: shift-out-of-bounds in __bch2_bkey_invalid
2024/05/31 13:21 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fda5695d692c 34889ee3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 UBSAN: shift-out-of-bounds in __bch2_bkey_invalid
2024/05/14 07:11 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fda5695d692c fdb4c10c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 UBSAN: shift-out-of-bounds in __bch2_bkey_invalid
2024/05/12 07:45 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fda5695d692c 9026e142 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 UBSAN: shift-out-of-bounds in __bch2_bkey_invalid
2024/05/05 17:05 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 78186bd77b47 610f2a54 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 UBSAN: shift-out-of-bounds in __bch2_bkey_invalid
* Struck through repros no longer work on HEAD.