================================================================== BUG: KCSAN: data-race in blkdev_read_iter / set_capacity_and_notify write to 0xffff888100661688 of 8 bytes by task 16857 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:1100 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 0xffff888100661688 of 8 bytes by task 1908 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: 1908 Comm: udevd Not tainted 6.0.0-rc3-syzkaller-00107-g42e66b1cc3a0-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 ================================================================== blk_print_req_error: 9 callbacks suppressed I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2 buffer_io_error: 6 callbacks suppressed Buffer I/O error on dev loop1, logical block 0, async page read I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2 Buffer I/O error on dev loop1, logical block 0, async page read I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2 Buffer I/O error on dev loop1, logical block 0, async page read I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2 Buffer I/O error on dev loop1, logical block 0, async page read I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2 Buffer I/O error on dev loop1, logical block 0, async page read I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2 I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2 Buffer I/O error on dev loop1, logical block 0, async page read I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2 Buffer I/O error on dev loop1, logical block 0, async page read I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2 Buffer I/O error on dev loop1, logical block 0, async page read Buffer I/O error on dev loop1, logical block 0, async page read loop1: unable to read partition table loop1: unable to read partition table blk_print_req_error: 11 callbacks suppressed I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2 buffer_io_error: 6 callbacks suppressed Buffer I/O error on dev loop1, logical block 0, async page read I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2 Buffer I/O error on dev loop1, logical block 0, async page read I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2 I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2 Buffer I/O error on dev loop1, logical block 0, async page read I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2 Buffer I/O error on dev loop1, logical block 0, async page read I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2 Buffer I/O error on dev loop1, logical block 0, async page read I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2 Buffer I/O error on dev loop1, logical block 0, async page read I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2 Buffer I/O error on dev loop1, logical block 0, async page read I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2 Buffer I/O error on dev loop1, logical block 0, async page read I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2 Buffer I/O error on dev loop1, logical block 0, async page read