Re: [syzbot] [hfs?] KMSAN: uninit-value in __hfs_ext_cache_extent (2)

[syzbot <syzbot+d395b0c369e492a17530@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
kernel BUG in hfs_write_inode

------------[ cut here ]------------
kernel BUG at fs/hfs/inode.c:444!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP PTI
CPU: 0 UID: 0 PID: 4551 Comm: kworker/u8:26 Not tainted 6.12.0-rc4-syzkaller-gc2ee9f594da8-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: writeback wb_workfn (flush-7:0)
RIP: 0010:hfs_write_inode+0xe81/0xe90 fs/hfs/inode.c:444
Code: e9 f4 fd ff ff 8b 3a e8 dd 6c 31 ff e9 02 fe ff ff 49 89 d6 8b 7d c8 e8 8d 68 31 ff 41 89 06 e9 26 fe ff ff e8 30 73 98 fe 90 <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 90 90 90 90 90 90 90
RSP: 0018:ffff888115ccb5c0 EFLAGS: 00010293
RAX: ffffffff831c8500 RBX: 0000000000000000 RCX: ffff8881151c8000
RDX: 0000000000000000 RSI: ffffffff91870ec0 RDI: 0000000000000000
RBP: ffff888115ccb6a8 R08: 0000000000000007 R09: ffffffff831c77bc
R10: 0000000000000003 R11: ffff8881151c8000 R12: 0000000000000000
R13: 0000000000000000 R14: ffff888012a7ca70 R15: ffff8881151c8b38
FS:  0000000000000000(0000) GS:ffff88813fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcdb4e446a8 CR3: 000000004484a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 write_inode fs/fs-writeback.c:1503 [inline]
 __writeback_single_inode+0x8da/0x1290 fs/fs-writeback.c:1723
 writeback_sb_inodes+0xa34/0x1c20 fs/fs-writeback.c:1954
 wb_writeback+0x4df/0xcb0 fs/fs-writeback.c:2134
 wb_do_writeback fs/fs-writeback.c:2281 [inline]
 wb_workfn+0x40b/0x1940 fs/fs-writeback.c:2321
 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
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:hfs_write_inode+0xe81/0xe90 fs/hfs/inode.c:444
Code: e9 f4 fd ff ff 8b 3a e8 dd 6c 31 ff e9 02 fe ff ff 49 89 d6 8b 7d c8 e8 8d 68 31 ff 41 89 06 e9 26 fe ff ff e8 30 73 98 fe 90 <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 90 90 90 90 90 90 90
RSP: 0018:ffff888115ccb5c0 EFLAGS: 00010293
RAX: ffffffff831c8500 RBX: 0000000000000000 RCX: ffff8881151c8000
RDX: 0000000000000000 RSI: ffffffff91870ec0 RDI: 0000000000000000
RBP: ffff888115ccb6a8 R08: 0000000000000007 R09: ffffffff831c77bc
R10: 0000000000000003 R11: ffff8881151c8000 R12: 0000000000000000
R13: 0000000000000000 R14: ffff888012a7ca70 R15: ffff8881151c8b38
FS:  0000000000000000(0000) GS:ffff88813fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcdb4e446a8 CR3: 000000004484a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


Tested on:

commit:         c2ee9f59 KVM: selftests: Fix build on on non-x86 archi..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14922640580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f0a45c444eedcbdb
dashboard link: https://syzkaller.appspot.com/bug?extid=d395b0c369e492a17530
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=164c4a5f980000