================================================================== BUG: KCSAN: data-race in loop_configure / shmem_write_begin read-write to 0xffff88813c2e8bd0 of 4 bytes by task 14636 on cpu 0: mapping_set_gfp_mask include/linux/pagemap.h:290 [inline] loop_configure+0x7c3/0xca0 drivers/block/loop.c:1077 lo_ioctl+0x682/0x12e0 blkdev_ioctl+0x38e/0x480 block/ioctl.c:615 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xc9/0x140 fs/ioctl.c:856 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffff88813c2e8bd0 of 4 bytes by task 14633 on cpu 1: mapping_gfp_mask include/linux/pagemap.h:274 [inline] shmem_get_folio mm/shmem.c:2080 [inline] shmem_write_begin+0x8a/0x1d0 mm/shmem.c:2573 generic_perform_write+0x1c3/0x3d0 mm/filemap.c:3923 __generic_file_write_iter+0xe6/0x290 mm/filemap.c:4051 generic_file_write_iter+0x7d/0x1c0 mm/filemap.c:4083 do_iter_write+0x4ae/0x770 fs/read_write.c:860 vfs_writev+0x1a2/0x310 fs/read_write.c:933 do_pwritev fs/read_write.c:1030 [inline] __do_sys_pwritev fs/read_write.c:1077 [inline] __se_sys_pwritev fs/read_write.c:1072 [inline] __x64_sys_pwritev+0x100/0x1c0 fs/read_write.c:1072 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x00100cca -> 0x00100c0a Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 14633 Comm: syz-executor.4 Not tainted 6.4.0-rc4-syzkaller-00047-gafead42fdfca #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 ==================================================================