syzbot

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BUG: KMSAN: uninit-value in __writepoint_find include/linux/rcupdate.h:-1 [inline]
BUG: KMSAN: uninit-value in writepoint_find fs/bcachefs/alloc_foreground.c:1248 [inline]
BUG: KMSAN: uninit-value in bch2_alloc_sectors_start_trans+0x44a/0x32d0 fs/bcachefs/alloc_foreground.c:1348
 __writepoint_find include/linux/rcupdate.h:-1 [inline]
 writepoint_find fs/bcachefs/alloc_foreground.c:1248 [inline]
 bch2_alloc_sectors_start_trans+0x44a/0x32d0 fs/bcachefs/alloc_foreground.c:1348
 __bch2_write+0x7bd/0x6a10 fs/bcachefs/io_write.c:1494
 bch2_write+0xdfe/0x1b30 fs/bcachefs/io_write.c:1681
 closure_queue include/linux/closure.h:270 [inline]
 closure_call include/linux/closure.h:432 [inline]
 bch2_writepage_do_io fs/bcachefs/fs-io-buffered.c:494 [inline]
 __bch2_writepage+0x22fd/0x3ab0 fs/bcachefs/fs-io-buffered.c:641
 write_cache_pages+0xc9/0x280 mm/page-writeback.c:2613
 bch2_writepages+0x11f/0x3c0 fs/bcachefs/fs-io-buffered.c:675
 do_writepages+0x427/0xc30 mm/page-writeback.c:2656
 __writeback_single_inode+0x103/0x1290 fs/fs-writeback.c:1680
 writeback_sb_inodes+0xac4/0x1c90 fs/fs-writeback.c:1976
 wb_writeback+0x4df/0xcb0 fs/fs-writeback.c:2156
 wb_do_writeback fs/fs-writeback.c:2303 [inline]
 wb_workfn+0x40b/0x1970 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xc1d/0x1e80 kernel/workqueue.c:3319
 worker_thread+0xea3/0x1500 kernel/workqueue.c:3400
 kthread+0x6ce/0xf10 kernel/kthread.c:464
 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Uninit was stored to memory at:
 bch2_writepage_io_alloc fs/bcachefs/fs-io-buffered.c:522 [inline]
 __bch2_writepage+0x3754/0x3ab0 fs/bcachefs/fs-io-buffered.c:644
 write_cache_pages+0xc9/0x280 mm/page-writeback.c:2613
 bch2_writepages+0x11f/0x3c0 fs/bcachefs/fs-io-buffered.c:675
 do_writepages+0x427/0xc30 mm/page-writeback.c:2656
 __writeback_single_inode+0x103/0x1290 fs/fs-writeback.c:1680
 writeback_sb_inodes+0xac4/0x1c90 fs/fs-writeback.c:1976
 wb_writeback+0x4df/0xcb0 fs/fs-writeback.c:2156
 wb_do_writeback fs/fs-writeback.c:2303 [inline]
 wb_workfn+0x40b/0x1970 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xc1d/0x1e80 kernel/workqueue.c:3319
 worker_thread+0xea3/0x1500 kernel/workqueue.c:3400
 kthread+0x6ce/0xf10 kernel/kthread.c:464
 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4167 [inline]
 slab_alloc_node mm/slub.c:4210 [inline]
 kmem_cache_alloc_lru_noprof+0x92d/0xe30 mm/slub.c:4229
 __bch2_new_inode+0x98/0x450 fs/bcachefs/fs.c:438
 __bch2_create+0x284/0x1700 fs/bcachefs/fs.c:541
 bch2_mknod fs/bcachefs/fs.c:728 [inline]
 bch2_create+0xc0/0x1d0 fs/bcachefs/fs.c:742
 lookup_open fs/namei.c:3701 [inline]
 open_last_lookups fs/namei.c:3800 [inline]
 path_openat+0x2efe/0x6280 fs/namei.c:4036
 do_filp_open+0x26b/0x610 fs/namei.c:4066
 do_sys_openat2+0x1ca/0x300 fs/open.c:1429
 do_sys_open fs/open.c:1444 [inline]
 __do_sys_openat fs/open.c:1460 [inline]
 __se_sys_openat fs/open.c:1455 [inline]
 __x64_sys_openat+0x2a1/0x310 fs/open.c:1455
 x64_sys_call+0x1fe/0x3c80 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x1b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 1 UID: 0 PID: 3735 Comm: kworker/u8:18 Tainted: G        W           6.15.0-rc2-syzkaller-00488-g6fea5fabd332 #0 PREEMPT(undef) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: writeback wb_workfn (flush-bcachefs-102)
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