syzbot


KCSAN: data-race in filemap_read / truncate_setsize (3)

Status: auto-closed as invalid on 2021/12/23 02:33
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 395d, last: 384d
similar bugs (4):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in filemap_read / truncate_setsize 1 597d 597d 0/24 auto-closed as invalid on 2021/05/24 01:14
upstream KCSAN: data-race in filemap_read / truncate_setsize (5) 2 182d 214d 0/24 auto-closed as invalid on 2022/07/13 18:41
upstream KCSAN: data-race in filemap_read / truncate_setsize (2) 1 445d 445d 0/24 auto-closed as invalid on 2021/10/23 13:44
upstream KCSAN: data-race in filemap_read / truncate_setsize (4) 1 267d 267d 0/24 auto-closed as invalid on 2022/04/19 18:12

Sample crash report:
==================================================================
BUG: KCSAN: data-race in filemap_read / truncate_setsize

write to 0xffff88814570b680 of 8 bytes by task 4670 on cpu 1:
 i_size_write include/linux/fs.h:913 [inline]
 truncate_setsize+0x2a/0xc0 mm/truncate.c:772
 simple_setattr+0x87/0xb0 fs/libfs.c:535
 notify_change+0x8a3/0xac0 fs/attr.c:410
 do_truncate+0xf7/0x140 fs/open.c:64
 handle_truncate fs/namei.c:3082 [inline]
 do_open fs/namei.c:3430 [inline]
 path_openat+0x191f/0x1eb0 fs/namei.c:3559
 do_filp_open+0x105/0x220 fs/namei.c:3586
 do_sys_openat2+0xb5/0x2b0 fs/open.c:1212
 do_sys_open fs/open.c:1228 [inline]
 __do_sys_creat fs/open.c:1304 [inline]
 __se_sys_creat fs/open.c:1298 [inline]
 __x64_sys_creat+0x62/0x80 fs/open.c:1298
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88814570b680 of 8 bytes by task 4667 on cpu 0:
 i_size_read include/linux/fs.h:891 [inline]
 filemap_read+0x1f5/0x16d0 mm/filemap.c:2639
 generic_file_read_iter+0x72/0x2a0 mm/filemap.c:2792
 call_read_iter include/linux/fs.h:2156 [inline]
 generic_file_splice_read+0x24f/0x330 fs/splice.c:311
 do_splice_to fs/splice.c:796 [inline]
 splice_direct_to_actor+0x2aa/0x650 fs/splice.c:870
 do_splice_direct+0x106/0x190 fs/splice.c:979
 do_sendfile+0x675/0xc40 fs/read_write.c:1245
 __do_sys_sendfile64 fs/read_write.c:1310 [inline]
 __se_sys_sendfile64 fs/read_write.c:1296 [inline]
 __x64_sys_sendfile64+0x102/0x140 fs/read_write.c:1296
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000000002f7601 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 4667 Comm: syz-executor.0 Not tainted 5.16.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/11/18 02:29 upstream ee1703cda8dc cafff8b6 .config log report info KCSAN: data-race in filemap_read / truncate_setsize
ci2-upstream-kcsan-gce 2021/11/07 11:09 upstream b5013d084e03 4c1be0be .config log report info KCSAN: data-race in filemap_read / truncate_setsize
* Struck through repros no longer work on HEAD.