KCSAN: data-race in file_remove_privs / generic_file_splice_read (2)

Status: auto-closed as invalid on 2021/06/09 14:16
Subsystems: fs
[Documentation on labels]
First crash: 1925d, last: 1925d
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in file_remove_privs / generic_file_splice_read fs 6 1 2225d 2225d 0/29 auto-closed as invalid on 2020/08/13 12:27

Sample crash report:
==================================================================
BUG: KCSAN: data-race in file_remove_privs / generic_file_splice_read

write to 0xffff8881301c307c of 4 bytes by task 12759 on cpu 0:
 inode_has_no_xattr include/linux/fs.h:3655 [inline]
 file_remove_privs+0x312/0x3a0 fs/inode.c:1947
 __generic_file_write_iter+0xdd/0x300 mm/filemap.c:3751
 generic_file_write_iter+0x75/0x130 mm/filemap.c:3837
 call_write_iter include/linux/fs.h:2116 [inline]
 do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740
 do_iter_write+0x112/0x4c0 fs/read_write.c:866
 vfs_iter_write+0x4c/0x70 fs/read_write.c:907
 iter_file_splice_write+0x40a/0x750 fs/splice.c:689
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:936
 splice_direct_to_actor+0x345/0x650 fs/splice.c:891
 do_splice_direct+0xf5/0x170 fs/splice.c:979
 do_sendfile+0x773/0xda0 fs/read_write.c:1260
 __do_sys_sendfile64 fs/read_write.c:1325 [inline]
 __se_sys_sendfile64 fs/read_write.c:1311 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881301c307c of 4 bytes by task 12745 on cpu 1:
 iocb_flags include/linux/fs.h:3509 [inline]
 init_sync_kiocb include/linux/fs.h:2283 [inline]
 generic_file_splice_read+0xe4/0x310 fs/splice.c:309
 do_splice_to fs/splice.c:796 [inline]
 splice_direct_to_actor+0x2aa/0x650 fs/splice.c:870
 do_splice_direct+0xf5/0x170 fs/splice.c:979
 do_sendfile+0x773/0xda0 fs/read_write.c:1260
 __do_sys_sendfile64 fs/read_write.c:1325 [inline]
 __se_sys_sendfile64 fs/read_write.c:1311 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 12745 Comm: syz-executor.3 Not tainted 5.12.0-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
2021/05/05 14:11 upstream d665ea6ea86c 06c27ff5 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in file_remove_privs / generic_file_splice_read
* Struck through repros no longer work on HEAD.