syzbot


KCSAN: data-race in generic_write_end / vfs_copy_file_range

Status: auto-closed as invalid on 2022/06/04 23:45
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 209d, last: 209d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in generic_write_end / vfs_copy_file_range

write to 0xffff888127110608 of 8 bytes by task 7180 on cpu 0:
 i_size_write include/linux/fs.h:878 [inline]
 generic_write_end+0x98/0x230 fs/buffer.c:2183
 ext4_da_write_end+0x446/0x510 fs/ext4/inode.c:3068
 generic_perform_write+0x26a/0x3f0 mm/filemap.c:3798
 ext4_buffered_write_iter+0x199/0x280 fs/ext4/file.c:270
 ext4_file_write_iter+0x211/0xdf0
 call_write_iter include/linux/fs.h:2050 [inline]
 new_sync_write fs/read_write.c:504 [inline]
 vfs_write+0x71c/0x890 fs/read_write.c:591
 ksys_write+0xe8/0x1a0 fs/read_write.c:644
 __do_sys_write fs/read_write.c:656 [inline]
 __se_sys_write fs/read_write.c:653 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:653
 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+0x44/0xae

read to 0xffff888127110608 of 8 bytes by task 7187 on cpu 1:
 i_size_read include/linux/fs.h:856 [inline]
 generic_copy_file_checks fs/read_write.c:1439 [inline]
 vfs_copy_file_range+0x2b8/0xe60 fs/read_write.c:1473
 __do_sys_copy_file_range fs/read_write.c:1562 [inline]
 __se_sys_copy_file_range+0x1ee/0x390 fs/read_write.c:1529
 __x64_sys_copy_file_range+0x74/0x80 fs/read_write.c:1529
 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+0x44/0xae

value changed: 0x00000000003cf000 -> 0x00000000003d0000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7187 Comm: syz-executor.0 Not tainted 5.18.0-rc4-syzkaller-00396-g57ae8a492116-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/04/30 23:41 upstream 57ae8a492116 2df221f6 .config log report info KCSAN: data-race in generic_write_end / vfs_copy_file_range
* Struck through repros no longer work on HEAD.