syzbot


KCSAN: data-race in ext4_dio_write_end_io / filemap_read (4)

Status: closed as invalid on 2022/05/13 11:20
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 209d, last: 209d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in ext4_dio_write_end_io / filemap_read 1 574d 574d 0/24 auto-closed as invalid on 2021/06/15 12:27
upstream KCSAN: data-race in ext4_dio_write_end_io / filemap_read (3) 8 349d 390d 0/24 auto-closed as invalid on 2022/01/25 16:20
upstream KCSAN: data-race in ext4_dio_write_end_io / filemap_read (2) 4 444d 520d 0/24 auto-closed as invalid on 2021/10/23 06:54

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

write to 0xffff888128ee61f8 of 8 bytes by task 10790 on cpu 1:
 i_size_write include/linux/fs.h:878 [inline]
 ext4_dio_write_end_io+0xd3/0x100 fs/ext4/file.c:399
 iomap_dio_complete+0xb8/0x3e0 fs/iomap/direct-io.c:79
 iomap_dio_rw+0x56/0x80 fs/iomap/direct-io.c:684
 ext4_dio_write_iter fs/ext4/file.c:566 [inline]
 ext4_file_write_iter+0xaa1/0x1210 fs/ext4/file.c:677
 do_iter_readv_writev+0x27b/0x300
 do_iter_write+0x16f/0x5c0 fs/read_write.c:852
 vfs_iter_write+0x4c/0x70 fs/read_write.c:893
 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:1246
 __do_sys_sendfile64 fs/read_write.c:1311 [inline]
 __se_sys_sendfile64 fs/read_write.c:1297 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1297
 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+0x44/0xae

read to 0xffff888128ee61f8 of 8 bytes by task 10796 on cpu 0:
 i_size_read include/linux/fs.h:856 [inline]
 filemap_read+0xde9/0x1400 mm/filemap.c:2691
 generic_file_read_iter+0x72/0x320 mm/filemap.c:2825
 ext4_file_read_iter+0x1e9/0x2a0
 call_read_iter include/linux/fs.h:2044 [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:1246
 __do_sys_sendfile64 fs/read_write.c:1311 [inline]
 __se_sys_sendfile64 fs/read_write.c:1297 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1297
 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+0x44/0xae

value changed: 0x000000000040b000 -> 0x000000000041a000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10796 Comm: syz-executor.5 Not tainted 5.18.0-rc6-syzkaller-00009-gfeb9c5e19e91 #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 2022/05/10 23:57 upstream feb9c5e19e91 8d7b3b67 .config log report info KCSAN: data-race in ext4_dio_write_end_io / filemap_read
* Struck through repros no longer work on HEAD.