linux-kernel - [syzbot] [bcachefs?] KMSAN: uninit-value in bch2_bucket_alloc

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Message-ID: <6755b44c.050a0220.2477f.002a.GAE@google.com>
Date: Sun, 08 Dec 2024 06:59:24 -0800
From: syzbot <syzbot+c761143a86b1640bc485@...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_bucket_alloc_trans

Hello,

syzbot found the following issue on:

HEAD commit:    ceb8bf2ceaa7 module: Convert default symbol namespace to s..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17f560f8580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=96ee18b6611821ab
dashboard link: https://syzkaller.appspot.com/bug?extid=c761143a86b1640bc485
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/2cdefe23324a/disk-ceb8bf2c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/db82aad0847e/vmlinux-ceb8bf2c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/616c479edfca/bzImage-ceb8bf2c.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c761143a86b1640bc485@...kaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in bch2_alloc_to_v4 fs/bcachefs/alloc_background.h:235 [inline]
BUG: KMSAN: uninit-value in try_alloc_bucket fs/bcachefs/alloc_foreground.c:314 [inline]
BUG: KMSAN: uninit-value in bch2_bucket_alloc_freelist fs/bcachefs/alloc_foreground.c:525 [inline]
BUG: KMSAN: uninit-value in bch2_bucket_alloc_trans+0x2533/0x3fb0 fs/bcachefs/alloc_foreground.c:648
 bch2_alloc_to_v4 fs/bcachefs/alloc_background.h:235 [inline]
 try_alloc_bucket fs/bcachefs/alloc_foreground.c:314 [inline]
 bch2_bucket_alloc_freelist fs/bcachefs/alloc_foreground.c:525 [inline]
 bch2_bucket_alloc_trans+0x2533/0x3fb0 fs/bcachefs/alloc_foreground.c:648
 bch2_bucket_alloc_set_trans+0x959/0x1650 fs/bcachefs/alloc_foreground.c:808
 __open_bucket_add_buckets+0x1dec/0x3070 fs/bcachefs/alloc_foreground.c:1057
 open_bucket_add_buckets+0x328/0x530 fs/bcachefs/alloc_foreground.c:1101
 bch2_alloc_sectors_start_trans+0x1833/0x32b0
 __bch2_btree_node_alloc fs/bcachefs/btree_update_interior.c:339 [inline]
 bch2_btree_reserve_get+0x9d6/0x2290 fs/bcachefs/btree_update_interior.c:549
 bch2_btree_update_start+0x1af9/0x2d60 fs/bcachefs/btree_update_interior.c:1247
 bch2_btree_node_rewrite+0x1da/0x1930 fs/bcachefs/btree_update_interior.c:2148
 async_btree_node_rewrite_trans fs/bcachefs/btree_update_interior.c:2236 [inline]
 async_btree_node_rewrite_work+0x485/0x1710 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]
 btree_key_cache_create fs/bcachefs/btree_key_cache.c:259 [inline]
 btree_key_cache_fill+0x13da/0x3d60 fs/bcachefs/btree_key_cache.c:309
 bch2_btree_path_traverse_cached+0x988/0xe20 fs/bcachefs/btree_key_cache.c:361
 bch2_btree_path_traverse_one+0x749/0x47b0 fs/bcachefs/btree_iter.c:1159
 bch2_btree_path_traverse fs/bcachefs/btree_iter.h:247 [inline]
 bch2_btree_iter_peek_slot+0x10b7/0x3950 fs/bcachefs/btree_iter.c:2629
 __bch2_bkey_get_iter fs/bcachefs/btree_iter.h:575 [inline]
 bch2_bkey_get_iter fs/bcachefs/btree_iter.h:589 [inline]
 try_alloc_bucket fs/bcachefs/alloc_foreground.c:305 [inline]
 bch2_bucket_alloc_freelist fs/bcachefs/alloc_foreground.c:525 [inline]
 bch2_bucket_alloc_trans+0x1bd5/0x3fb0 fs/bcachefs/alloc_foreground.c:648
 bch2_bucket_alloc_set_trans+0x959/0x1650 fs/bcachefs/alloc_foreground.c:808
 __open_bucket_add_buckets+0x1dec/0x3070 fs/bcachefs/alloc_foreground.c:1057
 open_bucket_add_buckets+0x328/0x530 fs/bcachefs/alloc_foreground.c:1101
 bch2_alloc_sectors_start_trans+0x1833/0x32b0
 __bch2_btree_node_alloc fs/bcachefs/btree_update_interior.c:339 [inline]
 bch2_btree_reserve_get+0x9d6/0x2290 fs/bcachefs/btree_update_interior.c:549
 bch2_btree_update_start+0x1af9/0x2d60 fs/bcachefs/btree_update_interior.c:1247
 bch2_btree_node_rewrite+0x1da/0x1930 fs/bcachefs/btree_update_interior.c:2148
 async_btree_node_rewrite_trans fs/bcachefs/btree_update_interior.c:2236 [inline]
 async_btree_node_rewrite_work+0x485/0x1710 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+0x2be/0xa80 fs/bcachefs/btree_cache.c:198
 bch2_fs_btree_cache_init+0x4e4/0xb50 fs/bcachefs/btree_cache.c:653
 bch2_fs_alloc fs/bcachefs/super.c:917 [inline]
 bch2_fs_open+0x4d3a/0x5b40 fs/bcachefs/super.c:2065
 bch2_fs_get_tree+0x983/0x22d0 fs/bcachefs/fs.c:2157
 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: 1 UID: 0 PID: 4195 Comm: kworker/u8:25 Not tainted 6.13.0-rc1-syzkaller-00005-gceb8bf2ceaa7 #0
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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