syzbot


KCSAN: data-race in ext4_dio_write_end_io / next_uptodate_page

Status: auto-closed as invalid on 2021/10/09 04:09
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 457d, last: 457d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ext4_dio_write_end_io / next_uptodate_page

write to 0xffff888106363b88 of 8 bytes by task 11159 on cpu 1:
 i_size_write include/linux/fs.h:916 [inline]
 ext4_dio_write_end_io+0xd3/0x100 fs/ext4/file.c:399
 iomap_dio_complete+0xb8/0x3c0 fs/iomap/direct-io.c:86
 iomap_dio_rw+0x4e/0x70 fs/iomap/direct-io.c:652
 ext4_dio_write_iter fs/ext4/file.c:568 [inline]
 ext4_file_write_iter+0xa5e/0x11a0 fs/ext4/file.c:678
 call_write_iter include/linux/fs.h:2163 [inline]
 do_iter_readv_writev+0x2cd/0x370 fs/read_write.c:729
 do_iter_write+0x192/0x5c0 fs/read_write.c:855
 vfs_iter_write+0x4c/0x70 fs/read_write.c:896
 iter_file_splice_write+0x40a/0x750 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+0xf5/0x170 fs/splice.c:979
 do_sendfile+0x618/0xb90 fs/read_write.c:1249
 __do_sys_sendfile64 fs/read_write.c:1314 [inline]
 __se_sys_sendfile64 fs/read_write.c:1300 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1300
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888106363b88 of 8 bytes by task 11195 on cpu 0:
 i_size_read include/linux/fs.h:894 [inline]
 next_uptodate_page+0x323/0x670 mm/filemap.c:3259
 next_map_page mm/filemap.c:3284 [inline]
 filemap_map_pages+0x761/0x870 mm/filemap.c:3340
 do_fault_around mm/memory.c:4151 [inline]
 do_read_fault mm/memory.c:4166 [inline]
 do_fault mm/memory.c:4300 [inline]
 handle_pte_fault mm/memory.c:4558 [inline]
 __handle_mm_fault mm/memory.c:4693 [inline]
 handle_mm_fault+0xd83/0x1a50 mm/memory.c:4791
 faultin_page mm/gup.c:951 [inline]
 __get_user_pages+0x32b/0xbc0 mm/gup.c:1173
 populate_vma_page_range mm/gup.c:1506 [inline]
 __mm_populate+0x24d/0x380 mm/gup.c:1615
 mm_populate include/linux/mm.h:2625 [inline]
 vm_mmap_pgoff+0x142/0x1d0 mm/util.c:524
 ksys_mmap_pgoff+0x2a8/0x380 mm/mmap.c:1629
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000000000f0000 -> 0x0000000000100000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 11195 Comm: syz-executor.5 Not tainted 5.14.0-syzkaller #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 2021/09/04 04:03 upstream a9c9a6f741cd d236a457 .config log report info KCSAN: data-race in ext4_dio_write_end_io / next_uptodate_page
* Struck through repros no longer work on HEAD.