Dear Linux folks,
Running Linux 5.17-rc2+ in QEMU 6.2.0, while running `apt install bluez
bluez-obexd bash-completion` in the VM the Kernel Concurrency Sanitizer
reports the race below.
qemu-system-x86_64 -cpu host -smp cpus=3 -m 2G -enable-kvm -usb
-device usb-host,vendorid=0x8087,productid=0x0a2a -drive
file=/dev/shm/debian-64.img,format=raw,if=virtio -net nic -net
user,hostfwd=tcp::22223-:22 -kernel /dev/shm/bzImage -append
"root=/dev/vda1 rw quiet"
```
[ 283.432792]
==================================================================
[ 283.433607] BUG: KCSAN: data-race in ext4_fill_raw_inode / setattr_copy
[ 283.434585] read to 0xffffa07f951c9c50 of 8 bytes by task 7 on cpu 1:
[ 283.435145] ext4_fill_raw_inode+0x2d9/0xa40
[ 283.435161] ext4_mark_iloc_dirty+0x25b/0xbf0
[ 283.435177] __ext4_mark_inode_dirty+0xb3/0x3a0
[ 283.435194] __ext4_ext_dirty+0x115/0x130
[ 283.435212] ext4_ext_map_blocks+0x1a12/0x2740
[ 283.435230] ext4_map_blocks+0x2e1/0x9e0
[ 283.435245] ext4_convert_unwritten_extents+0x210/0x320
[ 283.435265] ext4_convert_unwritten_io_end_vec+0xad/0x130
[ 283.435283] ext4_end_io_rsv_work+0x180/0x310
[ 283.435296] process_one_work+0x477/0x7d0
[ 283.435304] worker_thread+0x2ec/0x810
[ 283.435312] kthread+0x16d/0x1a0
[ 283.435322] ret_from_fork+0x22/0x30
[ 283.435599] write to 0xffffa07f951c9c50 of 16 bytes by task 1509 on
cpu 0:
[ 283.436138] setattr_copy+0x94/0x160
[ 283.436156] ext4_setattr+0x30f/0xf20
[ 283.436170] notify_change+0x34d/0x640
[ 283.436187] vfs_utimes+0x225/0x3d0
[ 283.436205] do_utimes+0xab/0x110
[ 283.436221] __x64_sys_utimensat+0xa9/0x100
[ 283.436240] do_syscall_64+0x39/0x80
[ 283.436257] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 283.436634] Reported by Kernel Concurrency Sanitizer on:
[ 283.437154] CPU: 0 PID: 1509 Comm: dpkg Not tainted
5.17.0-rc3-00369-gc67afd79c7ba #35
[ 283.437173] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 1.15.0-1 04/01/2014
[ 283.437184]
==================================================================
```
Please find the output of `dmesg` attached.
Kind regards,
Paul