syzbot


KCSAN: data-race in filemap_read / truncate_setsize (5)

Status: auto-closed as invalid on 2022/07/13 18:41
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 209d, last: 177d
similar bugs (4):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in filemap_read / truncate_setsize (3) 2 380d 391d 0/24 auto-closed as invalid on 2021/12/23 02:33
upstream KCSAN: data-race in filemap_read / truncate_setsize 1 593d 593d 0/24 auto-closed as invalid on 2021/05/24 01:14
upstream KCSAN: data-race in filemap_read / truncate_setsize (2) 1 440d 440d 0/24 auto-closed as invalid on 2021/10/23 13:44
upstream KCSAN: data-race in filemap_read / truncate_setsize (4) 1 262d 262d 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 0xffff888124024888 of 8 bytes by task 2933 on cpu 0:
 i_size_write include/linux/fs.h:871 [inline]
 truncate_setsize+0x2a/0xc0 mm/truncate.c:775
 simple_setattr+0x87/0xb0 fs/libfs.c:535
 notify_change+0x8e6/0xa00 fs/attr.c:410
 do_truncate+0xf7/0x140 fs/open.c:65
 handle_truncate fs/namei.c:3176 [inline]
 do_open fs/namei.c:3524 [inline]
 path_openat+0x1834/0x1b30 fs/namei.c:3653
 do_filp_open+0x105/0x220 fs/namei.c:3680
 do_sys_openat2+0xb5/0x2a0 fs/open.c:1278
 do_sys_open fs/open.c:1294 [inline]
 __do_sys_creat fs/open.c:1370 [inline]
 __se_sys_creat fs/open.c:1364 [inline]
 __x64_sys_creat+0x62/0x80 fs/open.c:1364
 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+0x46/0xb0

read to 0xffff888124024888 of 8 bytes by task 2930 on cpu 1:
 i_size_read include/linux/fs.h:849 [inline]
 filemap_read+0xde9/0x1400 mm/filemap.c:2691
 generic_file_read_iter+0x72/0x320 mm/filemap.c:2825
 call_read_iter include/linux/fs.h:2052 [inline]
 generic_file_splice_read+0x1de/0x2c0 fs/splice.c:311
 do_splice_to fs/splice.c:796 [inline]
 splice_direct_to_actor+0x2ac/0x660 fs/splice.c:870
 do_splice_direct+0xfb/0x180 fs/splice.c:979
 do_sendfile+0x3ad/0x900 fs/read_write.c:1262
 __do_sys_sendfile64 fs/read_write.c:1327 [inline]
 __se_sys_sendfile64 fs/read_write.c:1313 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1313
 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+0x46/0xb0

value changed: 0x0000000000282601 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 2930 Comm: syz-executor.2 Not tainted 5.19.0-rc1-syzkaller-00023-g34f4335c16a5-dirty #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 2022/06/08 18:37 upstream 34f4335c16a5 0d5abf15 .config log report info KCSAN: data-race in filemap_read / truncate_setsize
ci2-upstream-kcsan-gce 2022/05/07 18:09 upstream 4b97bac0756a e60b1103 .config log report info KCSAN: data-race in filemap_read / truncate_setsize
* Struck through repros no longer work on HEAD.