BUG: KCSAN: data-race in blkdev_read_iter / set_capacity_and_notify

write to 0xffff8881023d2708 of 8 bytes by task 29502 on cpu 0:
 set_capacity block/genhd.c:64 [inline]
 set_capacity_and_notify+0xab/0x1d0 block/genhd.c:78
 loop_set_size+0x2e/0x70 drivers/block/loop.c:237
 loop_configure+0xb1b/0xc30 drivers/block/loop.c:1095
 lo_ioctl+0x641/0x1290
 blkdev_ioctl+0x20e/0x440 block/ioctl.c:614
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:856
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff8881023d2708 of 8 bytes by task 5494 on cpu 1:
 bdev_nr_sectors include/linux/blkdev.h:790 [inline]
 bdev_nr_bytes include/linux/blkdev.h:795 [inline]
 blkdev_read_iter+0x40/0x370 block/fops.c:552
 call_read_iter include/linux/fs.h:2181 [inline]
 new_sync_read fs/read_write.c:389 [inline]
 vfs_read+0x3a5/0x560 fs/read_write.c:470
 ksys_read+0xe8/0x1a0 fs/read_write.c:607
 __do_sys_read fs/read_write.c:617 [inline]
 __se_sys_read fs/read_write.c:615 [inline]
 __x64_sys_read+0x3e/0x50 fs/read_write.c:615
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000000000000 -> 0x0000000000040800

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 5494 Comm: udevd Not tainted 6.0.0-rc2-syzkaller-00016-g072e51356cd5-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
==================================================================
 loop3: unable to read partition table
I/O error, dev loop4, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
 loop4: unable to read partition table
loop4: partition table beyond EOD, truncated
I/O error, dev loop4, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
 loop4: unable to read partition table
loop4: partition table beyond EOD, truncated
I/O error, dev loop4, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
 loop4: unable to read partition table
loop4: partition table beyond EOD, 
truncated
I/O error, dev loop4, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
buffer_io_error: 43 callbacks suppressed
Buffer I/O error on dev loop4, logical block 0, async page read
I/O error, dev loop0, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev loop0, logical block 0, async page read
Buffer I/O error on dev loop0, logical block 0, async page read
Buffer I/O error on dev loop4, logical block 0, async page read
Buffer I/O error on dev loop4, logical block 0, async page read
blk_print_req_error: 6 callbacks suppressed
I/O error, dev loop4, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev loop4, logical block 0, async page read
I/O error, dev loop4, sector 264064 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
I/O error, dev loop4, sector 264064 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
I/O error, dev loop4, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev loop4, logical block 0, async page read
I/O error, dev loop4, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev loop4, logical block 0, async page read
 loop4: unable to read partition table
loop4: partition table beyond EOD, truncated
I/O error, dev loop0, sector 24 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
I/O error, dev loop0, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
I/O error, dev loop4, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev loop4, logical block 0, async page read
 loop4: unable to read partition table
loop4: partition table beyond EOD, truncated
Buffer I/O error on dev loop4, logical block 0, async page read
Buffer I/O error on dev loop4, logical block 0, async page read
 loop4: unable to read partition table