[syzbot] [bcachefs?] KMSAN: uninit-value in bch2_btree_node_get

[syzbot] [bcachefs?] KMSAN: uninit-value in bch2_btree_node_get

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    445d9f05fa14 Merge tag 'nfsd-6.13' of git://git.kernel.org..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=112afff7980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c5486b9d7cc64830
dashboard link: https://syzkaller.appspot.com/bug?extid=2b2046c73fcb7e6a0e4e
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: i386

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7024ceac9339/disk-445d9f05.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ebf50afbcd15/vmlinux-445d9f05.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9e60e080ed9e/bzImage-445d9f05.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2b2046c73fcb7e6a0e4e@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in bch2_btree_node_get+0x605/0x18b0 fs/bcachefs/btree_cache.c:1180
 bch2_btree_node_get+0x605/0x18b0 fs/bcachefs/btree_cache.c:1180
 btree_path_down fs/bcachefs/btree_iter.c:956 [inline]
 bch2_btree_path_traverse_one+0x2c34/0x47b0 fs/bcachefs/btree_iter.c:1182
 bch2_btree_path_traverse fs/bcachefs/btree_iter.h:247 [inline]
 bch2_btree_iter_peek_node+0x2c5/0x15d0 fs/bcachefs/btree_iter.c:1901
 async_btree_node_rewrite_trans fs/bcachefs/btree_update_interior.c:2218 [inline]
 async_btree_node_rewrite_work+0x29d/0x1710 fs/bcachefs/btree_update_interior.c:2249
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3310
 worker_thread+0xea7/0x14f0 kernel/workqueue.c:3391
 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

Uninit was stored to memory at:
 memcpy_u64s_small fs/bcachefs/util.h:393 [inline]
 bkey_reassemble fs/bcachefs/bkey.h:513 [inline]
 bch2_bkey_buf_reassemble fs/bcachefs/bkey_buf.h:28 [inline]
 btree_node_iter_and_journal_peek+0x866/0x2520 fs/bcachefs/btree_iter.c:898
 btree_path_down fs/bcachefs/btree_iter.c:927 [inline]
 bch2_btree_path_traverse_one+0x254c/0x47b0 fs/bcachefs/btree_iter.c:1182
 bch2_btree_path_traverse fs/bcachefs/btree_iter.h:247 [inline]
 bch2_btree_iter_peek_node+0x2c5/0x15d0 fs/bcachefs/btree_iter.c:1901
 async_btree_node_rewrite_trans fs/bcachefs/btree_update_interior.c:2218 [inline]
 async_btree_node_rewrite_work+0x29d/0x1710 fs/bcachefs/btree_update_interior.c:2249
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3310
 worker_thread+0xea7/0x14f0 kernel/workqueue.c:3391
 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

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_node_data_alloc fs/bcachefs/btree_cache.c:153 [inline]
 bch2_btree_node_mem_alloc+0xa72/0x2ee0 fs/bcachefs/btree_cache.c:832
 __bch2_btree_node_alloc fs/bcachefs/btree_update_interior.c:321 [inline]
 bch2_btree_reserve_get+0x37f/0x2290 fs/bcachefs/btree_update_interior.c:549
 bch2_btree_update_start+0x1af9/0x2d60 fs/bcachefs/btree_update_interior.c:1247
 bch2_btree_split_leaf+0x120/0xc00 fs/bcachefs/btree_update_interior.c:1856
 bch2_trans_commit_error+0x1c0/0x1d60 fs/bcachefs/btree_trans_commit.c:942
 __bch2_trans_commit+0x210f/0xd190 fs/bcachefs/btree_trans_commit.c:1140
 bch2_trans_commit fs/bcachefs/btree_update.h:184 [inline]
 bch2_journal_replay+0x2e3d/0x4d30 fs/bcachefs/recovery.c:317
 bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:191 [inline]
 bch2_run_recovery_passes+0xaf9/0xf80 fs/bcachefs/recovery_passes.c:244
 bch2_fs_recovery+0x447b/0x5b00 fs/bcachefs/recovery.c:861
 bch2_fs_start+0x7b2/0xbd0 fs/bcachefs/super.c:1037
 bch2_fs_get_tree+0x13ea/0x22d0 fs/bcachefs/fs.c:2170
 vfs_get_tree+0xb1/0x5a0 fs/super.c:1814
 do_new_mount+0x71f/0x15e0 fs/namespace.c:3507
 path_mount+0x742/0x1f10 fs/namespace.c:3834
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4057 [inline]
 __se_sys_mount+0x722/0x810 fs/namespace.c:4034
 __ia32_sys_mount+0xe3/0x150 fs/namespace.c:4034
 ia32_sys_call+0x260e/0x4180 arch/x86/include/generated/asm/syscalls_32.h:22
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0xb0/0x110 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x38/0x80 arch/x86/entry/common.c:411
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:449
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

CPU: 0 UID: 0 PID: 7199 Comm: kworker/u8:2 Tainted: G        W          6.12.0-syzkaller-09734-g445d9f05fa14 #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: btree_node_rewrite async_btree_node_rewrite_work
=====================================================


---
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Re: [syzbot] [bcachefs?] KMSAN: uninit-value in bch2_btree_node_get

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    ac9c34d1e45a Merge tag 'for-linus' of git://git.kernel.org..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=17a4f7a4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d66f6f82ee090382
dashboard link: https://syzkaller.appspot.com/bug?extid=2b2046c73fcb7e6a0e4e
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=11da9c98580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=177a003f980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c756243ff2fa/disk-ac9c34d1.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/47bd399bb287/vmlinux-ac9c34d1.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b6c5db9fcba1/bzImage-ac9c34d1.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/039e65b899b2/mount_2.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2b2046c73fcb7e6a0e4e@syzkaller.appspotmail.com

bucket 0:127 gen 0 has wrong data_type: got free, should be sb, fixing
bucket 0:127 gen 0 data type sb has wrong dirty_sectors: got 0, should be 256, fixing
 done
bcachefs (loop0): going read-write
bcachefs (loop0): journal_replay...
=====================================================
BUG: KMSAN: uninit-value in bch2_btree_node_get+0x5ed/0x1970 fs/bcachefs/btree_cache.c:1180
 bch2_btree_node_get+0x5ed/0x1970 fs/bcachefs/btree_cache.c:1180
 btree_path_down fs/bcachefs/btree_iter.c:976 [inline]
 bch2_btree_path_traverse_one+0x283d/0x4790 fs/bcachefs/btree_iter.c:1202
 bch2_btree_path_traverse fs/bcachefs/btree_iter.h:249 [inline]
 bch2_btree_iter_traverse+0xbb8/0x1110 fs/bcachefs/btree_iter.c:1913
 bch2_journal_replay_key+0x28a/0x13f0 fs/bcachefs/recovery.c:264
 bch2_journal_replay+0x301d/0x4e20 fs/bcachefs/recovery.c:373
 bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:226 [inline]
 bch2_run_recovery_passes+0x5a2/0x1160 fs/bcachefs/recovery_passes.c:291
 bch2_fs_recovery+0x489c/0x6230 fs/bcachefs/recovery.c:936
 bch2_fs_start+0x7ca/0xc20 fs/bcachefs/super.c:1041
 bch2_fs_get_tree+0x1564/0x24e0 fs/bcachefs/fs.c:2203
 vfs_get_tree+0xb1/0x5a0 fs/super.c:1814
 do_new_mount+0x71f/0x15e0 fs/namespace.c:3560
 path_mount+0x742/0x1f10 fs/namespace.c:3887
 do_mount fs/namespace.c:3900 [inline]
 __do_sys_mount fs/namespace.c:4111 [inline]
 __se_sys_mount+0x71f/0x800 fs/namespace.c:4088
 __x64_sys_mount+0xe4/0x150 fs/namespace.c:4088
 x64_sys_call+0x39bf/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was stored to memory at:
 memcpy_u64s_small fs/bcachefs/util.h:416 [inline]
 bkey_reassemble fs/bcachefs/bkey.h:506 [inline]
 bch2_bkey_buf_reassemble fs/bcachefs/bkey_buf.h:28 [inline]
 btree_node_iter_and_journal_peek+0x889/0x2560 fs/bcachefs/btree_iter.c:918
 btree_path_down fs/bcachefs/btree_iter.c:947 [inline]
 bch2_btree_path_traverse_one+0x2131/0x4790 fs/bcachefs/btree_iter.c:1202
 bch2_btree_path_traverse fs/bcachefs/btree_iter.h:249 [inline]
 bch2_btree_iter_traverse+0xbb8/0x1110 fs/bcachefs/btree_iter.c:1913
 bch2_journal_replay_key+0x28a/0x13f0 fs/bcachefs/recovery.c:264
 bch2_journal_replay+0x301d/0x4e20 fs/bcachefs/recovery.c:373
 bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:226 [inline]
 bch2_run_recovery_passes+0x5a2/0x1160 fs/bcachefs/recovery_passes.c:291
 bch2_fs_recovery+0x489c/0x6230 fs/bcachefs/recovery.c:936
 bch2_fs_start+0x7ca/0xc20 fs/bcachefs/super.c:1041
 bch2_fs_get_tree+0x1564/0x24e0 fs/bcachefs/fs.c:2203
 vfs_get_tree+0xb1/0x5a0 fs/super.c:1814
 do_new_mount+0x71f/0x15e0 fs/namespace.c:3560
 path_mount+0x742/0x1f10 fs/namespace.c:3887
 do_mount fs/namespace.c:3900 [inline]
 __do_sys_mount fs/namespace.c:4111 [inline]
 __se_sys_mount+0x71f/0x800 fs/namespace.c:4088
 __x64_sys_mount+0xe4/0x150 fs/namespace.c:4088
 x64_sys_call+0x39bf/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 ___kmalloc_large_node+0x22c/0x370 mm/slub.c:4249
 __kmalloc_large_node_noprof+0x3f/0x1e0 mm/slub.c:4266
 __do_kmalloc_node mm/slub.c:4282 [inline]
 __kmalloc_node_noprof+0xc96/0x1250 mm/slub.c:4300
 __kvmalloc_node_noprof+0xc0/0x2d0 mm/util.c:662
 btree_node_data_alloc fs/bcachefs/btree_cache.c:156 [inline]
 bch2_btree_node_mem_alloc+0xa72/0x2ee0 fs/bcachefs/btree_cache.c:834
 __bch2_btree_node_alloc fs/bcachefs/btree_update_interior.c:304 [inline]
 bch2_btree_reserve_get+0x37f/0x2290 fs/bcachefs/btree_update_interior.c:532
 bch2_btree_update_start+0x2b0e/0x2d60 fs/bcachefs/btree_update_interior.c:1251
 bch2_btree_split_leaf+0x120/0xc90 fs/bcachefs/btree_update_interior.c:1853
 bch2_trans_commit_error+0x1c0/0x1d60 fs/bcachefs/btree_trans_commit.c:908
 __bch2_trans_commit+0x1d5f/0xd310 fs/bcachefs/btree_trans_commit.c:1089
 bch2_trans_commit fs/bcachefs/btree_update.h:183 [inline]
 bch2_journal_replay+0x3125/0x4e20 fs/bcachefs/recovery.c:373
 bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:226 [inline]
 bch2_run_recovery_passes+0x5a2/0x1160 fs/bcachefs/recovery_passes.c:291
 bch2_fs_recovery+0x489c/0x6230 fs/bcachefs/recovery.c:936
 bch2_fs_start+0x7ca/0xc20 fs/bcachefs/super.c:1041
 bch2_fs_get_tree+0x1564/0x24e0 fs/bcachefs/fs.c:2203
 vfs_get_tree+0xb1/0x5a0 fs/super.c:1814
 do_new_mount+0x71f/0x15e0 fs/namespace.c:3560
 path_mount+0x742/0x1f10 fs/namespace.c:3887
 do_mount fs/namespace.c:3900 [inline]
 __do_sys_mount fs/namespace.c:4111 [inline]
 __se_sys_mount+0x71f/0x800 fs/namespace.c:4088
 __x64_sys_mount+0xe4/0x150 fs/namespace.c:4088
 x64_sys_call+0x39bf/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 0 UID: 0 PID: 5784 Comm: syz-executor148 Not tainted 6.14.0-rc4-syzkaller-00052-gac9c34d1e45a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
=====================================================


---
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Re: [syzbot]

[syzbot]

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***

Subject: 
Author: kent.overstreet@linux.dev

#syz fix bcachefs: Disable asm memcpys when kmsan enabled