loop5: detected capacity change from 0 to 212992 ================================================================== BUG: KCSAN: data-race in shmem_add_to_page_cache / shmem_getattr write to 0xffff888132432320 of 8 bytes by task 1337 on cpu 0: shmem_add_to_page_cache+0x53d/0x660 mm/shmem.c:743 shmem_getpage_gfp+0xba5/0x13d0 mm/shmem.c:1935 shmem_getpage mm/shmem.c:151 [inline] shmem_file_read_iter+0x1b2/0x5d0 mm/shmem.c:2546 call_read_iter include/linux/fs.h:2157 [inline] do_iter_readv_writev+0x2fb/0x380 fs/read_write.c:727 do_iter_read+0x192/0x5d0 fs/read_write.c:790 vfs_iter_read+0x4c/0x70 fs/read_write.c:832 lo_read_simple drivers/block/loop.c:404 [inline] do_req_filebacked drivers/block/loop.c:675 [inline] loop_handle_cmd drivers/block/loop.c:2201 [inline] loop_process_work+0x11ae/0x18f0 drivers/block/loop.c:2241 loop_rootcg_workfn+0x1b/0x20 drivers/block/loop.c:2272 process_one_work+0x402/0x910 kernel/workqueue.c:2297 worker_thread+0x636/0xae0 kernel/workqueue.c:2444 kthread+0x262/0x280 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 read to 0xffff888132432320 of 8 bytes by task 28880 on cpu 1: shmem_getattr+0x71/0x260 mm/shmem.c:1070 vfs_getattr_nosec+0x153/0x2f0 fs/stat.c:123 vfs_getattr+0x4d/0x60 fs/stat.c:160 loop_get_status+0x261/0x330 drivers/block/loop.c:1613 loop_get_status64 drivers/block/loop.c:1721 [inline] lo_ioctl+0x1eb/0x13e0 drivers/block/loop.c:1866 blkdev_ioctl+0x1d0/0x3f0 block/ioctl.c:589 block_ioctl+0x6e/0x80 block/fops.c:477 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:860 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x0000000000000003 -> 0x0000000000000004 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 28880 Comm: syz-executor.5 Not tainted 5.15.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================