syzbot


KCSAN: data-race in __filemap_add_folio / generic_file_direct_write (3)

Status: auto-closed as invalid on 2022/06/12 06:31
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 276d, last: 271d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __filemap_add_folio / generic_file_direct_write 1 450d 450d 0/24 auto-closed as invalid on 2021/12/15 10:13
upstream KCSAN: data-race in __filemap_add_folio / generic_file_direct_write (2) 1 330d 330d 0/24 auto-closed as invalid on 2022/04/14 05:12
upstream KCSAN: data-race in __filemap_add_folio / generic_file_direct_write (4) 1 192d 192d 0/24 auto-closed as invalid on 2022/08/29 21:55

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __filemap_add_folio / generic_file_direct_write

read-write to 0xffff888122d7eb90 of 8 bytes by task 2918 on cpu 1:
 __filemap_add_folio+0x2d9/0x7f0 mm/filemap.c:904
 filemap_add_folio+0x6b/0x150 mm/filemap.c:959
 page_cache_ra_unbounded+0x19e/0x2e0 mm/readahead.c:243
 do_page_cache_ra mm/readahead.c:291 [inline]
 page_cache_ra_order mm/readahead.c:546 [inline]
 ondemand_readahead+0x5df/0x780 mm/readahead.c:668
 page_cache_sync_ra+0x1a4/0x1b0 mm/readahead.c:695
 page_cache_sync_readahead include/linux/pagemap.h:1185 [inline]
 filemap_get_pages mm/filemap.c:2592 [inline]
 filemap_read+0x3e5/0x1400 mm/filemap.c:2679
 generic_file_read_iter+0x72/0x320 mm/filemap.c:2825
 call_read_iter include/linux/fs.h:2044 [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:1246
 __do_sys_sendfile64 fs/read_write.c:1311 [inline]
 __se_sys_sendfile64 fs/read_write.c:1297 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1297
 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+0x44/0xae

read to 0xffff888122d7eb90 of 8 bytes by task 2919 on cpu 0:
 generic_file_direct_write+0x28a/0x400 mm/filemap.c:3729
 __generic_file_write_iter+0x11f/0x280 mm/filemap.c:3871
 generic_file_write_iter+0x75/0x130 mm/filemap.c:3947
 do_iter_readv_writev+0x27b/0x300
 do_iter_write+0x16f/0x5c0 fs/read_write.c:852
 vfs_iter_write+0x4c/0x70 fs/read_write.c:893
 iter_file_splice_write+0x44a/0x7c0 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+0x345/0x660 fs/splice.c:891
 do_splice_direct+0xfb/0x180 fs/splice.c:979
 do_sendfile+0x3ad/0x900 fs/read_write.c:1246
 __do_sys_sendfile64 fs/read_write.c:1311 [inline]
 __se_sys_sendfile64 fs/read_write.c:1297 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1297
 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+0x44/0xae

value changed: 0x000000000000015f -> 0x0000000000000160

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 2919 Comm: syz-executor.2 Not tainted 5.18.0-rc5-syzkaller-00178-g30c8e80f7932-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-upstream-kcsan-gce 2022/05/08 06:31 upstream 30c8e80f7932 e60b1103 .config console log report info KCSAN: data-race in __filemap_add_folio / generic_file_direct_write
ci2-upstream-kcsan-gce 2022/05/04 11:21 upstream 107c948d1d3e dc9e5259 .config console log report info KCSAN: data-race in __filemap_add_folio / generic_file_direct_write
ci2-upstream-kcsan-gce 2022/05/03 04:50 upstream 9050ba3a61a4 2df221f6 .config console log report info KCSAN: data-race in __filemap_add_folio / generic_file_direct_write
* Struck through repros no longer work on HEAD.