linux-kernel - [syzbot] [bcachefs?] KMSAN: uninit-value in bch2_dirent

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Message-ID: <6763f200.050a0220.15da49.000d.GAE@google.com>
Date: Thu, 19 Dec 2024 02:14:24 -0800
From: syzbot <syzbot+af2db1cea2ed7231e15b@...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_dirent_rename (2)

Hello,

syzbot found the following issue on:

HEAD commit:    a0e3919a2df2 Merge tag 'usb-6.13-rc3' of git://git.kernel...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=105407e8580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=95d0bb0535bcaca0
dashboard link: https://syzkaller.appspot.com/bug?extid=af2db1cea2ed7231e15b
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/458b3e5de594/disk-a0e3919a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/35b6151a9024/vmlinux-a0e3919a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5d6ac5e24841/bzImage-a0e3919a.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+af2db1cea2ed7231e15b@...kaller.appspotmail.com

bcachefs (loop3): check_allocations... done
bcachefs (loop3): going read-write
bcachefs (loop3): done starting filesystem
=====================================================
BUG: KMSAN: uninit-value in dirent_is_visible fs/bcachefs/dirent.c:88 [inline]
BUG: KMSAN: uninit-value in is_visible_key fs/bcachefs/str_hash.h:148 [inline]
BUG: KMSAN: uninit-value in bch2_hash_lookup_in_snapshot fs/bcachefs/str_hash.h:167 [inline]
BUG: KMSAN: uninit-value in bch2_hash_lookup fs/bcachefs/str_hash.h:195 [inline]
BUG: KMSAN: uninit-value in bch2_dirent_rename+0xa9c/0x5e30 fs/bcachefs/dirent.c:298
 dirent_is_visible fs/bcachefs/dirent.c:88 [inline]
 is_visible_key fs/bcachefs/str_hash.h:148 [inline]
 bch2_hash_lookup_in_snapshot fs/bcachefs/str_hash.h:167 [inline]
 bch2_hash_lookup fs/bcachefs/str_hash.h:195 [inline]
 bch2_dirent_rename+0xa9c/0x5e30 fs/bcachefs/dirent.c:298
 bch2_rename_trans+0xb47/0x26f0 fs/bcachefs/fs-common.c:417
 bch2_rename2+0x1863/0x3600 fs/bcachefs/fs.c:895
 vfs_rename+0x1d9d/0x2280 fs/namei.c:5067
 do_renameat2+0x18d0/0x1d50 fs/namei.c:5224
 __do_sys_rename fs/namei.c:5271 [inline]
 __se_sys_rename fs/namei.c:5269 [inline]
 __x64_sys_rename+0xe8/0x140 fs/namei.c:5269
 x64_sys_call+0x36cb/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:83
 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: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_prep_for_write+0x494/0x720 fs/bcachefs/btree_trans_commit.c:93
 bch2_trans_lock_write+0x7ef/0xc00 fs/bcachefs/btree_trans_commit.c:129
 do_bch2_trans_commit fs/bcachefs/btree_trans_commit.c:896 [inline]
 __bch2_trans_commit+0x31c4/0xd190 fs/bcachefs/btree_trans_commit.c:1121
 bch2_trans_commit fs/bcachefs/btree_update.h:184 [inline]
 __bch2_create+0xfd8/0x1700 fs/bcachefs/fs.c:540
 bch2_mknod fs/bcachefs/fs.c:673 [inline]
 bch2_create+0xc0/0x1d0 fs/bcachefs/fs.c:687
 lookup_open fs/namei.c:3649 [inline]
 open_last_lookups fs/namei.c:3748 [inline]
 path_openat+0x2e9e/0x6200 fs/namei.c:3984
 do_filp_open+0x268/0x600 fs/namei.c:4014
 do_sys_openat2+0x1bf/0x2f0 fs/open.c:1402
 do_sys_open fs/open.c:1417 [inline]
 __do_sys_creat fs/open.c:1495 [inline]
 __se_sys_creat fs/open.c:1489 [inline]
 __x64_sys_creat+0xe6/0x140 fs/open.c:1489
 x64_sys_call+0x12e3/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:86
 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: 25892 Comm: syz.3.5499 Not tainted 6.13.0-rc2-syzkaller-00333-ga0e3919a2df2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024
=====================================================


---
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