================================================================== BUG: KCSAN: data-race in filemap_read / generic_write_end write to 0xffff888123118a98 of 8 bytes by task 18191 on cpu 0: i_size_write include/linux/fs.h:886 [inline] generic_write_end+0xb1/0x350 fs/buffer.c:2183 ext4_da_write_end+0x26c/0x620 fs/ext4/inode.c:3089 generic_perform_write+0x264/0x3f0 mm/filemap.c:3749 ext4_buffered_write_iter+0x235/0x3e0 fs/ext4/file.c:270 ext4_file_write_iter+0x2e3/0x1210 do_iter_write+0x494/0x750 fs/read_write.c:855 vfs_iter_write+0x4c/0x70 fs/read_write.c:896 iter_file_splice_write+0x44a/0x7c0 fs/splice.c:686 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:931 splice_direct_to_actor+0x305/0x620 fs/splice.c:886 do_splice_direct+0xfb/0x180 fs/splice.c:974 do_sendfile+0x3bf/0x910 fs/read_write.c:1249 __do_sys_sendfile64 fs/read_write.c:1311 [inline] __se_sys_sendfile64 fs/read_write.c:1303 [inline] __x64_sys_sendfile64+0xb9/0x150 fs/read_write.c:1303 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 0xffff888123118a98 of 8 bytes by task 18196 on cpu 1: i_size_read include/linux/fs.h:864 [inline] filemap_read+0xd95/0x1430 mm/filemap.c:2672 generic_file_read_iter+0x72/0x320 mm/filemap.c:2806 ext4_file_read_iter+0x1e9/0x2a0 call_read_iter include/linux/fs.h:2181 [inline] generic_file_splice_read+0xde/0x2b0 fs/splice.c:309 do_splice_to fs/splice.c:793 [inline] splice_direct_to_actor+0x26c/0x620 fs/splice.c:865 do_splice_direct+0xfb/0x180 fs/splice.c:974 do_sendfile+0x3bf/0x910 fs/read_write.c:1249 __do_sys_sendfile64 fs/read_write.c:1317 [inline] __se_sys_sendfile64 fs/read_write.c:1303 [inline] __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1303 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: 0x0000000000000200 -> 0x0000000000000216 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 18196 Comm: syz-executor.1 Not tainted 6.0.0-rc4-syzkaller-00126-g26b1224903b3-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 ==================================================================