[syzbot] [bcachefs?] KMSAN: uninit-value in bch2_xattr_validate

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 62b5a46999c7 Merge tag '6.13-rc1-smb3-client-fixes' of git..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15a42b30580000
kernel config: https://syzkaller.appspot.com/x/.config?x=dcc2c6db74766fbc
dashboard link: https://syzkaller.appspot.com/bug?extid=983249082bd062b1c4ef
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/60049925b49e/disk-62b5a469.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b4566aa70779/vmlinux-62b5a469.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6ba7b00a199e/bzImage-62b5a469.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+983249...@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in bch2_xattr_validate+0x3bb/0x720 fs/bcachefs/xattr.c:81
bch2_xattr_validate+0x3bb/0x720 fs/bcachefs/xattr.c:81
bch2_bkey_val_validate+0x2b5/0x440 fs/bcachefs/bkey_methods.c:143
bset_key_validate fs/bcachefs/btree_io.c:841 [inline]
validate_bset_keys+0x1531/0x2080 fs/bcachefs/btree_io.c:910
validate_bset_for_write+0x142/0x290 fs/bcachefs/btree_io.c:1942
__bch2_btree_node_write+0x53df/0x6830 fs/bcachefs/btree_io.c:2152
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
__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

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
__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

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: 6046 Comm: bch-reclaim/loo Not tainted 6.13.0-rc1-syzkaller-00378-g62b5a46999c7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
=====================================================


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 4099a71718b0 Merge tag 'sched-urgent-2024-12-29' of git://..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=12886af8580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f9048090d7bb0d06

dashboard link: https://syzkaller.appspot.com/bug?extid=983249082bd062b1c4ef
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=1300550f980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15d8aac4580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/62835b60de83/disk-4099a717.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9262b999e6be/vmlinux-4099a717.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3fc8cec4d596/bzImage-4099a717.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/dad89746421f/mount_3.gz

___kmalloc_large_node+0x22c/0x370 mm/slub.c:4253
__kmalloc_large_node_noprof+0x3f/0x1e0 mm/slub.c:4270
__do_kmalloc_node mm/slub.c:4286 [inline]
__kmalloc_node_noprof+0xc96/0x1250 mm/slub.c:4304

__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: 5809 Comm: bch-reclaim/loo Not tainted 6.13.0-rc4-syzkaller-00110-g4099a71718b0 #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
=====================================================


---

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***

Subject:
Author: kent.ov...@linux.dev

#syz fix bcachefs: Disable asm memcpys when kmsan enabled

[syzbot]