syzbot

set_capacity_and_notify: 6 callbacks suppressed
loop7: detected capacity change from 0 to 7
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BUG: KCSAN: data-race in copy_folio_from_iter_atomic / read_lba

write to 0xffff88811d9c4000 of 14 bytes by task 3930 on cpu 1:
 memcpy_from_iter lib/iov_iter.c:85 [inline]
 iterate_bvec include/linux/iov_iter.h:123 [inline]
 iterate_and_advance2 include/linux/iov_iter.h:306 [inline]
 iterate_and_advance include/linux/iov_iter.h:330 [inline]
 __copy_from_iter lib/iov_iter.c:261 [inline]
 copy_folio_from_iter_atomic+0x743/0x10b0 lib/iov_iter.c:491
 iomap_write_iter fs/iomap/buffered-io.c:1158 [inline]
 iomap_file_buffered_write+0x421/0x8f0 fs/iomap/buffered-io.c:1225
 blkdev_buffered_write block/fops.c:735 [inline]
 blkdev_write_iter+0x3ae/0x4b0 block/fops.c:801
 iter_file_splice_write+0x6c4/0xa80 fs/splice.c:736
 do_splice_from fs/splice.c:936 [inline]
 direct_splice_actor+0x156/0x2a0 fs/splice.c:1159
 splice_direct_to_actor+0x311/0x670 fs/splice.c:1103
 do_splice_direct_actor fs/splice.c:1202 [inline]
 do_splice_direct+0x119/0x1a0 fs/splice.c:1228
 do_sendfile+0x382/0x650 fs/read_write.c:1372
 __do_sys_sendfile64 fs/read_write.c:1433 [inline]
 __se_sys_sendfile64 fs/read_write.c:1419 [inline]
 __x64_sys_sendfile64+0x105/0x150 fs/read_write.c:1419
 x64_sys_call+0x2dc4/0x3020 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811d9c4000 of 512 bytes by task 3928 on cpu 0:
 read_lba+0x132/0x1e0 block/partitions/efi.c:252
 find_valid_gpt block/partitions/efi.c:602 [inline]
 efi_partition+0x1df/0x1150 block/partitions/efi.c:719
 check_partition block/partitions/core.c:143 [inline]
 blk_add_partitions block/partitions/core.c:591 [inline]
 bdev_disk_changed+0x527/0xe00 block/partitions/core.c:695
 loop_reread_partitions+0x48/0xb0 drivers/block/loop.c:447
 loop_configure+0x982/0x9c0 drivers/block/loop.c:1096
 lo_ioctl+0x5aa/0x13a0 drivers/block/loop.c:1542
 blkdev_ioctl+0x387/0x460 block/ioctl.c:797
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xce/0x140 fs/ioctl.c:583
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:583
 x64_sys_call+0x1563/0x3020 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3928 Comm: syz.1.183 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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