syzbot


KCSAN: data-race in __filemap_add_folio / generic_file_direct_write (4)

Status: auto-closed as invalid on 2022/08/29 21:55
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 135d, last: 135d
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 (3) 3 213d 218d 0/24 auto-closed as invalid on 2022/06/12 06:31
upstream KCSAN: data-race in __filemap_add_folio / generic_file_direct_write 1 392d 392d 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 272d 272d 0/24 auto-closed as invalid on 2022/04/14 05:12

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

read-write to 0xffff888130573bd0 of 8 bytes by task 8263 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:245
 do_page_cache_ra mm/readahead.c:293 [inline]
 page_cache_ra_order mm/readahead.c:550 [inline]
 ondemand_readahead+0x5df/0x780 mm/readahead.c:672
 page_cache_sync_ra+0xdc/0xf0 mm/readahead.c:699
 page_cache_sync_readahead include/linux/pagemap.h:1234 [inline]
 filemap_get_pages mm/filemap.c:2594 [inline]
 filemap_read+0x3ef/0x1410 mm/filemap.c:2688
 generic_file_read_iter+0x72/0x320 mm/filemap.c:2834
 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+0x63/0xcd

read to 0xffff888130573bd0 of 8 bytes by task 8273 on cpu 0:
 generic_file_direct_write+0x28a/0x400 mm/filemap.c:3722
 __generic_file_write_iter+0x11f/0x280 mm/filemap.c:3863
 generic_file_write_iter+0x75/0x130 mm/filemap.c:3939
 do_iter_readv_writev+0x27b/0x300
 do_iter_write+0x16f/0x5c0 fs/read_write.c:868
 vfs_iter_write+0x4c/0x70 fs/read_write.c:909
 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: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+0x63/0xcd

value changed: 0x0000000000000143 -> 0x0000000000000145

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8273 Comm: syz-executor.3 Not tainted 5.19.0-rc8-syzkaller-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/07/25 21:54 upstream e0dccc3b76fb 34795c51 .config log report info KCSAN: data-race in __filemap_add_folio / generic_file_direct_write
* Struck through repros no longer work on HEAD.