[syzbot] [bcachefs?] UBSAN: shift-out-of-bounds in __btree_node_pinned

From: syzbot
Date: Wed Oct 02 2024 - 06:54:50 EST


Hello,

syzbot found the following issue on:

HEAD commit: ad46e8f95e93 Merge tag 'pm-6.12-rc1-2' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13b3d507980000
kernel config: https://syzkaller.appspot.com/x/.config?x=62086b2fd100a029
dashboard link: https://syzkaller.appspot.com/bug?extid=9f41e4b255897d99d4e9
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11b69e80580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1567c6a9980000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-ad46e8f9.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/72b7539cbeb1/vmlinux-ad46e8f9.xz
kernel image: https://storage.googleapis.com/syzbot-assets/73c9b9cebaf4/bzImage-ad46e8f9.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/54e2032c8f9d/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9f41e4b255897d99d4e9@xxxxxxxxxxxxxxxxxxxxxxxxx

------------[ cut here ]------------
UBSAN: shift-out-of-bounds in fs/bcachefs/btree_cache.c:198:18
shift exponent 227 is too large for 64-bit type 'unsigned long long'
CPU: 0 UID: 0 PID: 5109 Comm: read_btree_node Not tainted 6.11.0-syzkaller-11728-gad46e8f95e93 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
ubsan_epilogue lib/ubsan.c:231 [inline]
__ubsan_handle_shift_out_of_bounds+0x3c8/0x420 lib/ubsan.c:468
__btree_node_pinned+0x80b/0x850 fs/bcachefs/btree_cache.c:198
__bch2_btree_node_hash_insert+0xcfd/0x13e0 fs/bcachefs/btree_cache.c:270
bch2_btree_node_hash_insert fs/bcachefs/btree_cache.c:287 [inline]
bch2_btree_node_fill+0x94e/0x1200 fs/bcachefs/btree_cache.c:932
bch2_btree_node_get_noiter+0x9d5/0xf70 fs/bcachefs/btree_cache.c:1238
found_btree_node_is_readable fs/bcachefs/btree_node_scan.c:85 [inline]
try_read_btree_node fs/bcachefs/btree_node_scan.c:190 [inline]
read_btree_nodes_worker+0x122c/0x20b0 fs/bcachefs/btree_node_scan.c:239
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
---[ end trace ]---
Kernel panic - not syncing: UBSAN: panic_on_warn set ...
CPU: 0 UID: 0 PID: 5109 Comm: read_btree_node Not tainted 6.11.0-syzkaller-11728-gad46e8f95e93 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
panic+0x349/0x880 kernel/panic.c:354
check_panic_on_warn+0x86/0xb0 kernel/panic.c:243
ubsan_epilogue lib/ubsan.c:236 [inline]
__ubsan_handle_shift_out_of_bounds+0x3e7/0x420 lib/ubsan.c:468
__btree_node_pinned+0x80b/0x850 fs/bcachefs/btree_cache.c:198
__bch2_btree_node_hash_insert+0xcfd/0x13e0 fs/bcachefs/btree_cache.c:270
bch2_btree_node_hash_insert fs/bcachefs/btree_cache.c:287 [inline]
bch2_btree_node_fill+0x94e/0x1200 fs/bcachefs/btree_cache.c:932
bch2_btree_node_get_noiter+0x9d5/0xf70 fs/bcachefs/btree_cache.c:1238
found_btree_node_is_readable fs/bcachefs/btree_node_scan.c:85 [inline]
try_read_btree_node fs/bcachefs/btree_node_scan.c:190 [inline]
read_btree_nodes_worker+0x122c/0x20b0 fs/bcachefs/btree_node_scan.c:239
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
Kernel Offset: disabled
Rebooting in 86400 seconds..


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup