syzbot


KCSAN: data-race in __filemap_add_folio / dio_complete

Status: auto-closed as invalid on 2022/03/20 19:33
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 285d, last: 285d

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

write to 0xffff8881270df370 of 8 bytes by task 17820 on cpu 1:
 __filemap_add_folio+0x256/0x4d0 mm/filemap.c:897
 filemap_add_folio+0x6b/0x150 mm/filemap.c:950
 page_cache_ra_unbounded+0x274/0x400 mm/readahead.c:221
 ondemand_readahead+0x4f8/0x700
 page_cache_sync_ra+0xaf/0xe0 mm/readahead.c:579
 page_cache_sync_readahead include/linux/pagemap.h:1056 [inline]
 filemap_get_pages mm/filemap.c:2589 [inline]
 filemap_read+0x3ed/0x1430 mm/filemap.c:2676
 generic_file_read_iter+0x72/0x320 mm/filemap.c:2822
 call_read_iter include/linux/fs.h:2068 [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

read to 0xffff8881270df370 of 8 bytes by task 17837 on cpu 0:
 dio_complete+0x23b/0x490 fs/direct-io.c:290
 do_blockdev_direct_IO fs/direct-io.c:1330 [inline]
 __blockdev_direct_IO+0x22f2/0x2420 fs/direct-io.c:1362
 blockdev_direct_IO include/linux/fs.h:3203 [inline]
 fat_direct_IO+0x111/0x1e0 fs/fat/inode.c:288
 generic_file_direct_write+0x27c/0x410 mm/filemap.c:3689
 __generic_file_write_iter+0x13d/0x2b0 mm/filemap.c:3849
 generic_file_write_iter+0x75/0x130 mm/filemap.c:3924
 call_write_iter include/linux/fs.h:2074 [inline]
 do_iter_readv_writev+0x2de/0x380 fs/read_write.c:725
 do_iter_write+0x192/0x5c0 fs/read_write.c:851
 vfs_iter_write+0x4c/0x70 fs/read_write.c:892
 iter_file_splice_write+0x43a/0x790 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+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: 0x00000000000000e1 -> 0x00000000000000e2

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 17837 Comm: syz-executor.2 Not tainted 5.17.0-rc3-syzkaller-00329-g42964a18f81c-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/02/13 19:31 upstream 42964a18f81c 8b9ca619 .config log report info KCSAN: data-race in __filemap_add_folio / dio_complete
* Struck through repros no longer work on HEAD.