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KCSAN: data-race in ext4_page_mkwrite / ext4_write_end

Status: auto-closed as invalid on 2021/10/20 22:01
Subsystems: ext4
[Documentation on labels]
First crash: 925d, last: 925d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ext4_page_mkwrite / ext4_write_end

write to 0xffff888105fa5b48 of 8 bytes by task 16192 on cpu 1:
 i_size_write include/linux/fs.h:916 [inline]
 ext4_update_inode_size fs/ext4/ext4.h:3421 [inline]
 ext4_write_end+0x1be/0x800 fs/ext4/inode.c:1311
 ext4_da_write_end+0x93/0x730 fs/ext4/inode.c:3085
 generic_perform_write+0x251/0x3e0 mm/filemap.c:3781
 ext4_buffered_write_iter+0x309/0x400 fs/ext4/file.c:269
 ext4_file_write_iter+0x2f4/0x11f0
 call_write_iter include/linux/fs.h:2163 [inline]
 aio_write+0x2b1/0x380 fs/aio.c:1578
 io_submit_one+0x86f/0x13b0 fs/aio.c:1880
 __do_sys_io_submit fs/aio.c:1939 [inline]
 __se_sys_io_submit+0x105/0x270 fs/aio.c:1909
 __x64_sys_io_submit+0x3f/0x50 fs/aio.c:1909
 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

read to 0xffff888105fa5b48 of 8 bytes by task 16207 on cpu 0:
 i_size_read include/linux/fs.h:894 [inline]
 ext4_page_mkwrite+0x5f6/0xec0 fs/ext4/inode.c:6113
 do_page_mkwrite mm/memory.c:2870 [inline]
 wp_page_shared mm/memory.c:3203 [inline]
 do_wp_page+0x86c/0xba0 mm/memory.c:3304
 handle_pte_fault mm/memory.c:4576 [inline]
 __handle_mm_fault mm/memory.c:4693 [inline]
 handle_mm_fault+0x96e/0x1580 mm/memory.c:4791
 do_user_addr_fault+0x609/0xbe0 arch/x86/mm/fault.c:1390
 handle_page_fault arch/x86/mm/fault.c:1475 [inline]
 exc_page_fault+0x91/0x220 arch/x86/mm/fault.c:1531
 asm_exc_page_fault+0x1e/0x30
 __put_user_nocheck_8+0x3/0x21
 __do_sys_io_setup fs/aio.c:1331 [inline]
 __se_sys_io_setup+0x91/0x1a0 fs/aio.c:1311
 __x64_sys_io_setup+0x2d/0x40 fs/aio.c:1311
 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: 0x00000000024df000 -> 0x00000000024e0000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 16207 Comm: syz-executor.1 Not tainted 5.15.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/09/15 21:56 upstream 80be5998ad63 07e953c1 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in ext4_page_mkwrite / ext4_write_end
* Struck through repros no longer work on HEAD.