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KCSAN: data-race in filemap_fdatawrite_wbc / xas_clear_mark (5)

Status: moderation: reported on 2024/07/31 14:50
Subsystems: fs mm
[Documentation on labels]
Reported-by: syzbot+85eb8a800f8262c81ee5@syzkaller.appspotmail.com
First crash: 42d, last: 27d
Similar bugs (4)
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 497d 497d 0/27 auto-obsoleted due to no activity on 2023/06/08 03:34
upstream KCSAN: data-race in filemap_fdatawrite_wbc / xas_clear_mark (3) mm fs 2 295d 276d 0/27 auto-obsoleted due to no activity on 2023/12/26 21:21
upstream KCSAN: data-race in filemap_fdatawrite_wbc / xas_clear_mark mm fs 1 603d 603d 0/27 auto-obsoleted due to no activity on 2023/03/14 19:57
upstream KCSAN: data-race in filemap_fdatawrite_wbc / xas_clear_mark (4) fs mm 1 89d 89d 0/27 auto-obsoleted due to no activity on 2024/07/19 18:06

Sample crash report:
EXT4-fs (loop0): 1 truncate cleaned up
EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback.
==================================================================
BUG: KCSAN: data-race in filemap_fdatawrite_wbc / xas_clear_mark

write to 0xffff8881060bd94c of 4 bytes by task 3566 on cpu 0:
 xa_mark_clear lib/xarray.c:77 [inline]
 xas_clear_mark+0x169/0x180 lib/xarray.c:925
 __folio_start_writeback+0x2d9/0x440 mm/page-writeback.c:3152
 ext4_bio_write_folio+0x58b/0x9a0 fs/ext4/page-io.c:554
 mpage_submit_folio fs/ext4/inode.c:1943 [inline]
 mpage_process_page_bufs+0x486/0x5d0 fs/ext4/inode.c:2056
 mpage_prepare_extent_to_map+0x788/0xb80 fs/ext4/inode.c:2564
 ext4_do_writepages+0xa20/0x2110 fs/ext4/inode.c:2751
 ext4_writepages+0x159/0x2e0 fs/ext4/inode.c:2842
 do_writepages+0x1d8/0x480 mm/page-writeback.c:2683
 filemap_fdatawrite_wbc+0xdb/0x100 mm/filemap.c:397
 __filemap_fdatawrite_range mm/filemap.c:430 [inline]
 file_write_and_wait_range+0xc8/0x170 mm/filemap.c:788
 generic_buffers_fsync_noflush+0x4c/0x130 fs/buffer.c:600
 ext4_fsync_nojournal fs/ext4/fsync.c:88 [inline]
 ext4_sync_file+0x20b/0x6c0 fs/ext4/fsync.c:151
 vfs_fsync_range+0x122/0x140 fs/sync.c:188
 generic_write_sync include/linux/fs.h:2821 [inline]
 ext4_buffered_write_iter+0x338/0x380 fs/ext4/file.c:305
 ext4_file_write_iter+0x29f/0xe30
 iter_file_splice_write+0x5e6/0x970 fs/splice.c:743
 do_splice_from fs/splice.c:941 [inline]
 direct_splice_actor+0x16c/0x2c0 fs/splice.c:1164
 splice_direct_to_actor+0x305/0x670 fs/splice.c:1108
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x3ab/0x950 fs/read_write.c:1295
 __do_sys_sendfile64 fs/read_write.c:1362 [inline]
 __se_sys_sendfile64 fs/read_write.c:1348 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1348
 x64_sys_call+0xed5/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881060bd94c of 4 bytes by task 3564 on cpu 1:
 xa_marked include/linux/xarray.h:424 [inline]
 mapping_tagged include/linux/fs.h:502 [inline]
 filemap_fdatawrite_wbc+0x5c/0x100 mm/filemap.c:393
 __filemap_fdatawrite_range mm/filemap.c:430 [inline]
 file_write_and_wait_range+0xc8/0x170 mm/filemap.c:788
 generic_buffers_fsync_noflush+0x4c/0x130 fs/buffer.c:600
 ext4_fsync_nojournal fs/ext4/fsync.c:88 [inline]
 ext4_sync_file+0x20b/0x6c0 fs/ext4/fsync.c:151
 vfs_fsync_range+0x122/0x140 fs/sync.c:188
 generic_write_sync include/linux/fs.h:2821 [inline]
 ext4_buffered_write_iter+0x338/0x380 fs/ext4/file.c:305
 ext4_file_write_iter+0x29f/0xe30
 iter_file_splice_write+0x5e6/0x970 fs/splice.c:743
 do_splice_from fs/splice.c:941 [inline]
 direct_splice_actor+0x16c/0x2c0 fs/splice.c:1164
 splice_direct_to_actor+0x305/0x670 fs/splice.c:1108
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x3ab/0x950 fs/read_write.c:1295
 __do_sys_sendfile64 fs/read_write.c:1362 [inline]
 __se_sys_sendfile64 fs/read_write.c:1348 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1348
 x64_sys_call+0xed5/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0e000021 -> 0x04000021

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3564 Comm: syz.0.55 Not tainted 6.11.0-rc3-syzkaller-00066-g1fb918967b56 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/08/15 17:21 upstream 1fb918967b56 e4bacdaf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in filemap_fdatawrite_wbc / xas_clear_mark
2024/07/31 14:50 upstream e4fc196f5ba3 6fde257d .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.