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Date: Sat, 11 May 2024 13:52:29 -0700
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Subject: [syzbot] [bcachefs?] KMSAN: uninit-value in bch2_extent_update_i_size_sectors
From: syzbot <syzbot+eceea46e8838baeeba67@syzkaller.appspotmail.com>
To: bfoster@redhat.com, kent.overstreet@linux.dev, 
	linux-bcachefs@vger.kernel.org, linux-kernel@vger.kernel.org, 
	syzkaller-bugs@googlegroups.com
Content-Type: text/plain; charset="UTF-8"

Hello,

syzbot found the following issue on:

HEAD commit:    dccb07f2914c Merge tag 'for-6.9-rc7-tag' of git://git.kern..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14c66e24980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=617171361dd3cd47
dashboard link: https://syzkaller.appspot.com/bug?extid=eceea46e8838baeeba67
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/fdbc7be30633/disk-dccb07f2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a9e4c11aa835/vmlinux-dccb07f2.xz
kernel image: https://storage.googleapis.com/syzbot-assets/43c3a343ea93/bzImage-dccb07f2.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+eceea46e8838baeeba67@syzkaller.appspotmail.com

bcachefs (loop0): snapshots_read... done
bcachefs (loop0): journal_replay... done
bcachefs (loop0): resume_logged_ops... done
bcachefs (loop0): going read-write
bcachefs (loop0): done starting filesystem
=====================================================
BUG: KMSAN: uninit-value in bch2_extent_update_i_size_sectors+0x140f/0x17d0 fs/bcachefs/io_write.c:237
 bch2_extent_update_i_size_sectors+0x140f/0x17d0 fs/bcachefs/io_write.c:237
 bch2_extent_update+0x4f5/0xac0 fs/bcachefs/io_write.c:314
 bch2_write_index_default fs/bcachefs/io_write.c:366 [inline]
 __bch2_write_index+0x1653/0x2bd0 fs/bcachefs/io_write.c:520
 bch2_write_data_inline fs/bcachefs/io_write.c:1538 [inline]
 bch2_write+0x1a13/0x1b40 fs/bcachefs/io_write.c:1606
 closure_queue include/linux/closure.h:257 [inline]
 closure_call include/linux/closure.h:390 [inline]
 bch2_writepage_do_io fs/bcachefs/fs-io-buffered.c:468 [inline]
 bch2_writepages+0x24a/0x3c0 fs/bcachefs/fs-io-buffered.c:660
 do_writepages+0x427/0xc30 mm/page-writeback.c:2612
 filemap_fdatawrite_wbc+0x1d8/0x270 mm/filemap.c:397
 __filemap_fdatawrite_range+0xe3/0x120 mm/filemap.c:430
 sync_file_range+0x316/0x450 fs/sync.c:292
 ksys_sync_file_range fs/sync.c:364 [inline]
 __do_sys_sync_file_range fs/sync.c:373 [inline]
 __se_sys_sync_file_range fs/sync.c:370 [inline]
 __x64_sys_sync_file_range+0x15a/0x2a0 fs/sync.c:370
 x64_sys_call+0xc90/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:278
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/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:511 [inline]
 bkey_reassemble fs/bcachefs/bkey.h:505 [inline]
 __bch2_bkey_make_mut_noupdate fs/bcachefs/btree_update.h:225 [inline]
 __bch2_bkey_get_mut_noupdate fs/bcachefs/btree_update.h:282 [inline]
 bch2_bkey_get_mut_noupdate fs/bcachefs/btree_update.h:293 [inline]
 bch2_extent_update_i_size_sectors+0x9a9/0x17d0 fs/bcachefs/io_write.c:219
 bch2_extent_update+0x4f5/0xac0 fs/bcachefs/io_write.c:314
 bch2_write_index_default fs/bcachefs/io_write.c:366 [inline]
 __bch2_write_index+0x1653/0x2bd0 fs/bcachefs/io_write.c:520
 bch2_write_data_inline fs/bcachefs/io_write.c:1538 [inline]
 bch2_write+0x1a13/0x1b40 fs/bcachefs/io_write.c:1606
 closure_queue include/linux/closure.h:257 [inline]
 closure_call include/linux/closure.h:390 [inline]
 bch2_writepage_do_io fs/bcachefs/fs-io-buffered.c:468 [inline]
 bch2_writepages+0x24a/0x3c0 fs/bcachefs/fs-io-buffered.c:660
 do_writepages+0x427/0xc30 mm/page-writeback.c:2612
 filemap_fdatawrite_wbc+0x1d8/0x270 mm/filemap.c:397
 __filemap_fdatawrite_range+0xe3/0x120 mm/filemap.c:430
 sync_file_range+0x316/0x450 fs/sync.c:292
 ksys_sync_file_range fs/sync.c:364 [inline]
 __do_sys_sync_file_range fs/sync.c:373 [inline]
 __se_sys_sync_file_range fs/sync.c:370 [inline]
 __x64_sys_sync_file_range+0x15a/0x2a0 fs/sync.c:370
 x64_sys_call+0xc90/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:278
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/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:511 [inline]
 bkey_reassemble fs/bcachefs/bkey.h:505 [inline]
 btree_key_cache_fill fs/bcachefs/btree_key_cache.c:454 [inline]
 bch2_btree_path_traverse_cached_slowpath+0x5f02/0x79f0 fs/bcachefs/btree_key_cache.c:530
 bch2_btree_path_traverse_cached+0xd1a/0x1140
 bch2_btree_path_traverse_one+0x737/0x5290 fs/bcachefs/btree_iter.c:1155
 bch2_btree_path_traverse fs/bcachefs/btree_iter.h:225 [inline]
 bch2_btree_iter_peek_slot+0x128c/0x3840 fs/bcachefs/btree_iter.c:2473
 __bch2_bkey_get_iter fs/bcachefs/btree_iter.h:549 [inline]
 __bch2_bkey_get_mut_noupdate fs/bcachefs/btree_update.h:278 [inline]
 bch2_bkey_get_mut_noupdate fs/bcachefs/btree_update.h:293 [inline]
 bch2_extent_update_i_size_sectors+0x404/0x17d0 fs/bcachefs/io_write.c:219
 bch2_extent_update+0x4f5/0xac0 fs/bcachefs/io_write.c:314
 bch2_write_index_default fs/bcachefs/io_write.c:366 [inline]
 __bch2_write_index+0x1653/0x2bd0 fs/bcachefs/io_write.c:520
 bch2_write_data_inline fs/bcachefs/io_write.c:1538 [inline]
 bch2_write+0x1a13/0x1b40 fs/bcachefs/io_write.c:1606
 closure_queue include/linux/closure.h:257 [inline]
 closure_call include/linux/closure.h:390 [inline]
 bch2_writepage_do_io fs/bcachefs/fs-io-buffered.c:468 [inline]
 bch2_writepages+0x24a/0x3c0 fs/bcachefs/fs-io-buffered.c:660
 do_writepages+0x427/0xc30 mm/page-writeback.c:2612
 filemap_fdatawrite_wbc+0x1d8/0x270 mm/filemap.c:397
 __filemap_fdatawrite_range+0xe3/0x120 mm/filemap.c:430
 sync_file_range+0x316/0x450 fs/sync.c:292
 ksys_sync_file_range fs/sync.c:364 [inline]
 __do_sys_sync_file_range fs/sync.c:373 [inline]
 __se_sys_sync_file_range fs/sync.c:370 [inline]
 __x64_sys_sync_file_range+0x15a/0x2a0 fs/sync.c:370
 x64_sys_call+0xc90/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:278
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 __kmalloc_large_node+0x231/0x370 mm/slub.c:3927
 __do_kmalloc_node mm/slub.c:3960 [inline]
 __kmalloc_node+0xb10/0x10c0 mm/slub.c:3979
 kmalloc_node include/linux/slab.h:648 [inline]
 kvmalloc_node+0xc0/0x2d0 mm/util.c:634
 kvmalloc include/linux/slab.h:766 [inline]
 btree_bounce_alloc fs/bcachefs/btree_io.c:118 [inline]
 bch2_btree_node_read_done+0x4e68/0x75e0 fs/bcachefs/btree_io.c:1185
 btree_node_read_work+0x8a5/0x1eb0 fs/bcachefs/btree_io.c:1324
 bch2_btree_node_read+0x3d42/0x4b50
 __bch2_btree_root_read fs/bcachefs/btree_io.c:1748 [inline]
 bch2_btree_root_read+0xa6c/0x13d0 fs/bcachefs/btree_io.c:1772
 read_btree_roots+0x454/0xee0 fs/bcachefs/recovery.c:457
 bch2_fs_recovery+0x7adb/0x9310 fs/bcachefs/recovery.c:785
 bch2_fs_start+0x7b2/0xbd0 fs/bcachefs/super.c:1043
 bch2_fs_open+0x135f/0x1670 fs/bcachefs/super.c:2102
 bch2_mount+0x90d/0x1d90 fs/bcachefs/fs.c:1903
 legacy_get_tree+0x114/0x290 fs/fs_context.c:662
 vfs_get_tree+0xa7/0x570 fs/super.c:1779
 do_new_mount+0x71f/0x15e0 fs/namespace.c:3352
 path_mount+0x742/0x1f20 fs/namespace.c:3679
 do_mount fs/namespace.c:3692 [inline]
 __do_sys_mount fs/namespace.c:3898 [inline]
 __se_sys_mount+0x725/0x810 fs/namespace.c:3875
 __x64_sys_mount+0xe4/0x150 fs/namespace.c:3875
 x64_sys_call+0x2bf4/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 1 PID: 6218 Comm: syz-executor.0 Not tainted 6.9.0-rc7-syzkaller-00012-gdccb07f2914c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
=====================================================


---
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