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KCSAN: data-race in __vfs_setxattr_noperm / ext4_file_read_iter

Status: closed as invalid on 2020/06/18 14:24
Subsystems: ext4
[Documentation on labels]
First crash: 1417d, last: 1417d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __vfs_setxattr_noperm / ext4_file_read_iter

write to 0xffff888120fe20f4 of 4 bytes by task 25325 on cpu 0:
 __vfs_setxattr_noperm+0x90/0x2b0 fs/xattr.c:179
 vfs_setxattr+0xcb/0xe0 fs/xattr.c:224
 setxattr+0x22a/0x310 fs/xattr.c:451
 path_setxattr+0x132/0x160 fs/xattr.c:470
 __do_sys_setxattr fs/xattr.c:485 [inline]
 __se_sys_setxattr fs/xattr.c:481 [inline]
 __x64_sys_setxattr+0x72/0x90 fs/xattr.c:481
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888120fe20f4 of 4 bytes by task 25318 on cpu 1:
 ext4_file_read_iter+0xb0/0x360 fs/ext4/file.c:125
 call_read_iter include/linux/fs.h:1901 [inline]
 generic_file_splice_read+0x2df/0x470 fs/splice.c:313
 do_splice_to+0xc7/0x100 fs/splice.c:892
 splice_direct_to_actor+0x1b9/0x540 fs/splice.c:971
 do_splice_direct+0x152/0x1d0 fs/splice.c:1080
 do_sendfile+0x380/0x800 fs/read_write.c:1521
 __do_sys_sendfile64 fs/read_write.c:1582 [inline]
 __se_sys_sendfile64 fs/read_write.c:1568 [inline]
 __x64_sys_sendfile64+0x121/0x140 fs/read_write.c:1568
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 25318 Comm: syz-executor.5 Not tainted 5.7.0-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
2020/05/11 11:16 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 f8f57555 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.