==================================================================
BUG: KCSAN: data-race in blkdev_read_iter / set_capacity_and_notify

write to 0xffff888101bbe688 of 8 bytes by task 23861 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+0xb52/0xc70 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+0x46/0xb0

read to 0xffff888101bbe688 of 8 bytes by task 14699 on cpu 1:
 bdev_nr_sectors include/linux/blkdev.h:792 [inline]
 bdev_nr_bytes include/linux/blkdev.h:797 [inline]
 blkdev_read_iter+0x40/0x370 block/fops.c:548
 call_read_iter include/linux/fs.h:2035 [inline]
 new_sync_read fs/read_write.c:401 [inline]
 vfs_read+0x5a5/0x6a0 fs/read_write.c:482
 ksys_read+0xe8/0x1a0 fs/read_write.c:620
 __do_sys_read fs/read_write.c:630 [inline]
 __se_sys_read fs/read_write.c:628 [inline]
 __x64_sys_read+0x3e/0x50 fs/read_write.c:628
 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+0x46/0xb0

value changed: 0x0000000000000000 -> 0x00000000000000fb

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 14699 Comm: udevd Not tainted 5.18.0-syzkaller-09061-g16477cdfefdb-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
blk_print_req_error: 27 callbacks suppressed
I/O error, dev loop2, sector 264064 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
I/O error, dev loop1, sector 147328 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
I/O error, dev loop1, sector 147328 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
I/O error, dev loop1, sector 147328 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
I/O error, dev loop2, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
I/O error, dev loop2, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
I/O error, dev loop2, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
I/O error, dev loop1, sector 264064 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
I/O error, dev loop4, sector 8064 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
blk_print_req_error: 3 callbacks suppressed
I/O error, dev loop5, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
I/O error, dev loop5, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
I/O error, dev loop2, sector 8064 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
I/O error, dev loop2, sector 8064 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
I/O error, dev loop5, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
I/O error, dev loop2, sector 8064 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
I/O error, dev loop2, sector 8064 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
I/O error, dev loop5, sector 264064 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0