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KCSAN: data-race in filemap_fdatawrite_wbc / xas_clear_mark (3)

Status: auto-obsoleted due to no activity on 2023/12/26 21:21
Subsystems: fs mm
[Documentation on labels]
Reported-by: syzbot+b129f4f3252883c3c7da@syzkaller.appspotmail.com
First crash: 121d, last: 94d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in filemap_fdatawrite_wbc / xas_clear_mark (2) fs mm 1 295d 295d 0/26 auto-obsoleted due to no activity on 2023/06/08 03:34
upstream KCSAN: data-race in filemap_fdatawrite_wbc / xas_clear_mark fs mm 1 402d 402d 0/26 auto-obsoleted due to no activity on 2023/03/14 19:57

Sample crash report:
==================================================================
BUG: KCSAN: data-race in filemap_fdatawrite_wbc / xas_clear_mark

write to 0xffff88810612b4dc of 4 bytes by task 8890 on cpu 0:
 xa_mark_clear lib/xarray.c:77 [inline]
 xas_clear_mark+0x165/0x180 lib/xarray.c:924
 __folio_start_writeback+0x31d/0x4b0 mm/page-writeback.c:3026
 ext4_bio_write_folio+0x592/0x9a0 fs/ext4/page-io.c:557
 mpage_submit_folio fs/ext4/inode.c:1875 [inline]
 mpage_process_page_bufs+0x488/0x5d0 fs/ext4/inode.c:1988
 mpage_prepare_extent_to_map+0x780/0xb70 fs/ext4/inode.c:2496
 ext4_do_writepages+0xa20/0x2100 fs/ext4/inode.c:2683
 ext4_writepages+0x15e/0x2e0 fs/ext4/inode.c:2774
 do_writepages+0x1c2/0x340 mm/page-writeback.c:2553
 filemap_fdatawrite_wbc+0xdb/0xf0 mm/filemap.c:387
 __filemap_fdatawrite_range mm/filemap.c:420 [inline]
 file_write_and_wait_range+0xf4/0x190 mm/filemap.c:778
 generic_buffers_fsync_noflush+0x4c/0x120 fs/buffer.c:603
 ext4_fsync_nojournal fs/ext4/fsync.c:88 [inline]
 ext4_sync_file+0x206/0x6c0 fs/ext4/fsync.c:151
 vfs_fsync_range+0x111/0x120 fs/sync.c:188
 generic_write_sync include/linux/fs.h:2653 [inline]
 ext4_buffered_write_iter+0x334/0x370 fs/ext4/file.c:305
 ext4_file_write_iter+0x297/0xe10
 do_iter_write+0x4ad/0x770 fs/read_write.c:860
 vfs_iter_write+0x56/0x70 fs/read_write.c:901
 iter_file_splice_write+0x462/0x7e0 fs/splice.c:736
 do_splice_from fs/splice.c:933 [inline]
 direct_splice_actor+0x8a/0xb0 fs/splice.c:1142
 splice_direct_to_actor+0x31d/0x690 fs/splice.c:1088
 do_splice_direct+0x10d/0x190 fs/splice.c:1194
 do_sendfile+0x3c4/0x980 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1322 [inline]
 __se_sys_sendfile64 fs/read_write.c:1308 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff88810612b4dc of 4 bytes by task 8904 on cpu 1:
 xa_marked include/linux/xarray.h:420 [inline]
 mapping_tagged include/linux/fs.h:507 [inline]
 filemap_fdatawrite_wbc+0x5c/0xf0 mm/filemap.c:383
 __filemap_fdatawrite_range mm/filemap.c:420 [inline]
 file_write_and_wait_range+0xf4/0x190 mm/filemap.c:778
 generic_buffers_fsync_noflush+0x4c/0x120 fs/buffer.c:603
 ext4_fsync_nojournal fs/ext4/fsync.c:88 [inline]
 ext4_sync_file+0x206/0x6c0 fs/ext4/fsync.c:151
 vfs_fsync_range+0x111/0x120 fs/sync.c:188
 generic_write_sync include/linux/fs.h:2653 [inline]
 ext4_buffered_write_iter+0x334/0x370 fs/ext4/file.c:305
 ext4_file_write_iter+0x297/0xe10
 do_iter_write+0x4ad/0x770 fs/read_write.c:860
 vfs_iter_write+0x56/0x70 fs/read_write.c:901
 iter_file_splice_write+0x462/0x7e0 fs/splice.c:736
 do_splice_from fs/splice.c:933 [inline]
 direct_splice_actor+0x8a/0xb0 fs/splice.c:1142
 splice_direct_to_actor+0x31d/0x690 fs/splice.c:1088
 do_splice_direct+0x10d/0x190 fs/splice.c:1194
 do_sendfile+0x3c4/0x980 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1322 [inline]
 __se_sys_sendfile64 fs/read_write.c:1308 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x1c000021 -> 0x08000021

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8904 Comm: syz-executor.3 Not tainted 6.7.0-rc2-syzkaller-00014-gc2d5304e6c64 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/11/21 21:20 upstream c2d5304e6c64 cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in filemap_fdatawrite_wbc / xas_clear_mark
2023/10/25 07:12 upstream 4f82870119a4 17e6d526 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in filemap_fdatawrite_wbc / xas_clear_mark
* Struck through repros no longer work on HEAD.