linux-kernel - [syzbot] [bcachefs?] KMSAN: uninit-value in bch2_checksum

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Message-ID: <675e8eec.050a0220.37aaf.00f4.GAE@google.com>
Date: Sun, 15 Dec 2024 00:10:20 -0800
From: syzbot <syzbot+60ea31958b52b09e04af@...kaller.appspotmail.com>
To: kent.overstreet@...ux.dev, linux-bcachefs@...r.kernel.org, 
	linux-kernel@...r.kernel.org, syzkaller-bugs@...glegroups.com
Subject: [syzbot] [bcachefs?] KMSAN: uninit-value in bch2_checksum_update (2)

Hello,

syzbot found the following issue on:

HEAD commit:    f92f4749861b Merge tag 'clk-fixes-for-linus' of git://git...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=129b3544580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=95d0bb0535bcaca0
dashboard link: https://syzkaller.appspot.com/bug?extid=60ea31958b52b09e04af
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/71d71ad0e41a/disk-f92f4749.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3c061489bceb/vmlinux-f92f4749.xz
kernel image: https://storage.googleapis.com/syzbot-assets/30c84208490c/bzImage-f92f4749.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+60ea31958b52b09e04af@...kaller.appspotmail.com

bcachefs (loop9): shutting down
bcachefs (loop9): going read-only
bcachefs (loop9): finished waiting for writes to stop
bcachefs (loop9): flushing journal and stopping allocators, journal seq 11
=====================================================
BUG: KMSAN: uninit-value in crc64_be+0x202/0x310 lib/crc64.c:59
 crc64_be+0x202/0x310 lib/crc64.c:59
 bch2_checksum_update+0x15e/0x1d0 fs/bcachefs/checksum.c:88
 bch2_checksum+0x3ca/0x800 fs/bcachefs/checksum.c:225
 __bch2_btree_node_write+0x52e3/0x6830 fs/bcachefs/btree_io.c:2148
 bch2_btree_node_write+0xa5/0x2e0 fs/bcachefs/btree_io.c:2284
 btree_node_write_if_need fs/bcachefs/btree_io.h:151 [inline]
 __btree_node_flush+0x606/0x680 fs/bcachefs/btree_trans_commit.c:252
 bch2_btree_node_flush1+0x38/0x60 fs/bcachefs/btree_trans_commit.c:266
 journal_flush_pins+0xce6/0x1780 fs/bcachefs/journal_reclaim.c:565
 journal_flush_done+0x156/0x3f0 fs/bcachefs/journal_reclaim.c:822
 bch2_journal_flush_pins+0xdb/0x3b0 fs/bcachefs/journal_reclaim.c:852
 bch2_journal_flush_all_pins fs/bcachefs/journal_reclaim.h:76 [inline]
 __bch2_fs_read_only+0x210/0xb40 fs/bcachefs/super.c:276
 bch2_fs_read_only+0xd2c/0x15d0 fs/bcachefs/super.c:356
 __bch2_fs_stop+0xf0/0xf10 fs/bcachefs/super.c:621
 bch2_put_super+0x3c/0x50 fs/bcachefs/fs.c:2050
 generic_shutdown_super+0x197/0x4c0 fs/super.c:642
 bch2_kill_sb+0x3d/0x70 fs/bcachefs/fs.c:2278
 deactivate_locked_super+0xe0/0x3f0 fs/super.c:473
 deactivate_super+0x14f/0x160 fs/super.c:506
 cleanup_mnt+0x6bb/0x730 fs/namespace.c:1373
 __cleanup_mnt+0x22/0x30 fs/namespace.c:1380
 task_work_run+0x268/0x310 kernel/task_work.c:239
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xbf/0x160 kernel/entry/common.c:218
 do_syscall_64+0xda/0x1e0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was stored to memory at:
 memcpy_u64s_small fs/bcachefs/util.h:393 [inline]
 bkey_p_copy fs/bcachefs/bkey.h:47 [inline]
 bch2_sort_keys_keep_unwritten_whiteouts+0x12d5/0x19d0 fs/bcachefs/bkey_sort.c:187
 __bch2_btree_node_write+0x3ae8/0x6830 fs/bcachefs/btree_io.c:2095
 bch2_btree_node_write+0xa5/0x2e0 fs/bcachefs/btree_io.c:2284
 btree_node_write_if_need fs/bcachefs/btree_io.h:151 [inline]
 __btree_node_flush+0x606/0x680 fs/bcachefs/btree_trans_commit.c:252
 bch2_btree_node_flush1+0x38/0x60 fs/bcachefs/btree_trans_commit.c:266
 journal_flush_pins+0xce6/0x1780 fs/bcachefs/journal_reclaim.c:565
 journal_flush_done+0x156/0x3f0 fs/bcachefs/journal_reclaim.c:822
 bch2_journal_flush_pins+0xdb/0x3b0 fs/bcachefs/journal_reclaim.c:852
 bch2_journal_flush_all_pins fs/bcachefs/journal_reclaim.h:76 [inline]
 __bch2_fs_read_only+0x210/0xb40 fs/bcachefs/super.c:276
 bch2_fs_read_only+0xd2c/0x15d0 fs/bcachefs/super.c:356
 __bch2_fs_stop+0xf0/0xf10 fs/bcachefs/super.c:621
 bch2_put_super+0x3c/0x50 fs/bcachefs/fs.c:2050
 generic_shutdown_super+0x197/0x4c0 fs/super.c:642
 bch2_kill_sb+0x3d/0x70 fs/bcachefs/fs.c:2278
 deactivate_locked_super+0xe0/0x3f0 fs/super.c:473
 deactivate_super+0x14f/0x160 fs/super.c:506
 cleanup_mnt+0x6bb/0x730 fs/namespace.c:1373
 __cleanup_mnt+0x22/0x30 fs/namespace.c:1380
 task_work_run+0x268/0x310 kernel/task_work.c:239
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xbf/0x160 kernel/entry/common.c:218
 do_syscall_64+0xda/0x1e0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 ___kmalloc_large_node+0x22c/0x370 mm/slub.c:4238
 __kmalloc_large_node_noprof+0x3f/0x1e0 mm/slub.c:4255
 __do_kmalloc_node mm/slub.c:4271 [inline]
 __kmalloc_node_noprof+0xc96/0x1250 mm/slub.c:4289
 __kvmalloc_node_noprof+0xc0/0x2d0 mm/util.c:650
 btree_bounce_alloc fs/bcachefs/btree_io.c:124 [inline]
 btree_node_sort+0x78a/0x1d30 fs/bcachefs/btree_io.c:323
 bch2_btree_post_write_cleanup+0x1b0/0xf20 fs/bcachefs/btree_io.c:2248
 bch2_btree_node_write+0x21c/0x2e0 fs/bcachefs/btree_io.c:2289
 btree_node_write_if_need fs/bcachefs/btree_io.h:151 [inline]
 __btree_node_flush+0x606/0x680 fs/bcachefs/btree_trans_commit.c:252
 bch2_btree_node_flush0+0x35/0x60 fs/bcachefs/btree_trans_commit.c:261
 journal_flush_pins+0xce6/0x1780 fs/bcachefs/journal_reclaim.c:565
 __bch2_journal_reclaim+0xda8/0x1670 fs/bcachefs/journal_reclaim.c:698
 bch2_journal_reclaim_thread+0x18e/0x760 fs/bcachefs/journal_reclaim.c:740
 kthread+0x3e2/0x540 kernel/kthread.c:389
 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

CPU: 0 UID: 0 PID: 13300 Comm: syz-executor Tainted: G        W          6.13.0-rc2-syzkaller-00031-gf92f4749861b #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
=====================================================


---
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