KCSAN: data-race in generic_file_buffered_read / generic_write_end

Status: auto-closed as invalid on 2021/03/11 10:35
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+f6f4cbb70f468745b776@syzkaller.appspotmail.com
First crash: 2258d, last: 2032d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in generic_file_buffered_read / generic_write_end

write to 0xffff88810d6afb90 of 8 bytes by task 15828 on cpu 1:
 i_size_write include/linux/fs.h:870 [inline]
 generic_write_end+0x99/0x240 fs/buffer.c:2186
 ext4_da_write_end+0x59b/0x760 fs/ext4/inode.c:3111
 generic_perform_write+0x23e/0x3a0 mm/filemap.c:3419
 ext4_buffered_write_iter+0x2e5/0x3e0 fs/ext4/file.c:270
 ext4_file_write_iter+0x47a/0x1060 fs/ext4/file.c:503
 call_write_iter include/linux/fs.h:1901 [inline]
 do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740
 do_iter_write+0x112/0x4c0 fs/read_write.c:866
 vfs_iter_write+0x4c/0x70 fs/read_write.c:907
 iter_file_splice_write+0x41a/0x770 fs/splice.c:686
 do_splice_from fs/splice.c:764 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:933
 splice_direct_to_actor+0x345/0x650 fs/splice.c:888
 do_splice_direct+0xf5/0x170 fs/splice.c:976
 do_sendfile+0x5e0/0xcf0 fs/read_write.c:1257
 __do_sys_sendfile64 fs/read_write.c:1312 [inline]
 __se_sys_sendfile64 fs/read_write.c:1304 [inline]
 __x64_sys_sendfile64+0xa9/0x130 fs/read_write.c:1304
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88810d6afb90 of 8 bytes by task 15820 on cpu 0:
 i_size_read include/linux/fs.h:848 [inline]
 generic_file_buffered_read+0x290/0x9c0 mm/filemap.c:2496
 generic_file_read_iter+0x82/0x3e0 mm/filemap.c:2633
 ext4_file_read_iter+0x2e0/0x430 fs/ext4/file.c:74
 call_read_iter include/linux/fs.h:1895 [inline]
 generic_file_splice_read+0x22a/0x310 fs/splice.c:311
 do_splice_to fs/splice.c:788 [inline]
 splice_direct_to_actor+0x2aa/0x650 fs/splice.c:867
 do_splice_direct+0xf5/0x170 fs/splice.c:976
 do_sendfile+0x5e0/0xcf0 fs/read_write.c:1257
 __do_sys_sendfile64 fs/read_write.c:1318 [inline]
 __se_sys_sendfile64 fs/read_write.c:1304 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1304
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 15820 Comm: syz-executor.1 Not tainted 5.11.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (170):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/02/04 10:34 upstream 61556703b610 624dad51 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in generic_file_buffered_read / generic_write_end
2021/02/01 01:11 upstream 1048ba83fb1c fc9fd31e .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in generic_file_buffered_read / generic_write_end
2021/01/10 20:54 upstream 0653161f0fac 2c1f2513 .config console log report info ci2-upstream-kcsan-gce
2021/01/09 23:12 upstream 2ff90100ace8 2c1f2513 .config console log report info ci2-upstream-kcsan-gce
2021/01/04 21:06 upstream 36bbbd0e234d 2a28ff1f .config console log report info ci2-upstream-kcsan-gce
2020/12/15 09:54 upstream 148842c98a24 97183ed7 .config console log report info ci2-upstream-kcsan-gce
2020/12/14 20:35 upstream fab0fca1da5c 97183ed7 .config console log report info ci2-upstream-kcsan-gce
2020/12/10 11:10 upstream a2f5ea9e314b 2a55c22b .config console log report info ci2-upstream-kcsan-gce
2020/12/07 08:45 upstream 0477e9288185 f80ce148 .config console log report info ci2-upstream-kcsan-gce
2020/12/04 18:38 upstream e87297fa080a 20366b87 .config console log report info ci2-upstream-kcsan-gce
2020/12/02 23:56 upstream 3bb61aa61828 8c9190ef .config console log report info ci2-upstream-kcsan-gce
2020/11/29 00:16 upstream 67f34fa8893e a0092f9d .config console log report info ci2-upstream-kcsan-gce
2020/11/28 12:38 upstream c84e1efae022 3c7136c0 .config console log report info ci2-upstream-kcsan-gce
2020/11/26 23:36 upstream 4df910620beb 5018c946 .config console log report info ci2-upstream-kcsan-gce
2020/11/24 20:48 upstream 80145ac2f739 e34b696c .config console log report info ci2-upstream-kcsan-gce
2020/11/18 18:07 upstream 0fa8ee0d9ab9 0767f13f .config console log report info ci2-upstream-kcsan-gce
2020/11/17 21:35 upstream 111e91a6df50 09323409 .config console log report info ci2-upstream-kcsan-gce
2020/11/01 18:44 upstream 31f020064f9d 8bc4594f .config console log report info ci2-upstream-kcsan-gce
2020/10/31 11:03 upstream 5fc6b075e165 8bc4594f .config console log report info ci2-upstream-kcsan-gce
2020/10/26 23:01 upstream 41ba50b0572e 8b3eaf58 .config console log report info ci2-upstream-kcsan-gce
2020/10/26 09:00 upstream 3650b228f83a a1839e81 .config console log report info ci2-upstream-kcsan-gce
2020/10/25 19:08 upstream 986b9eacb259 a1839e81 .config console log report info ci2-upstream-kcsan-gce
2020/10/24 09:11 upstream f11901ed723d 2bb6666c .config console log report info ci2-upstream-kcsan-gce
2020/10/22 00:38 upstream f804b3159482 be6b1582 .config console log report info ci2-upstream-kcsan-gce
2020/10/19 09:03 upstream 7cf726a59435 ff4a3345 .config console log report info ci2-upstream-kcsan-gce
2020/10/18 17:57 upstream 9453b2d4694c fea47c01 .config console log report info ci2-upstream-kcsan-gce
2020/10/15 00:03 upstream 3e4fb4346c78 fc7735a2 .config console log report info ci2-upstream-kcsan-gce
2020/10/12 08:13 upstream bbf5c979011a 4a77ae0b .config console log report info ci2-upstream-kcsan-gce
2020/10/11 18:51 upstream 3dd0130f2430 4a77ae0b .config console log report info ci2-upstream-kcsan-gce
2020/10/09 21:47 upstream 8a5f78d98c26 93817d89 .config console log report info ci2-upstream-kcsan-gce
2020/10/08 10:33 upstream c85fb28b6f99 92390980 .config console log report info ci2-upstream-kcsan-gce
2020/10/05 13:26 upstream 549738f15da0 1880b4a9 .config console log report info ci2-upstream-kcsan-gce
2020/10/05 00:03 upstream 549738f15da0 5ef9c291 .config console log report info ci2-upstream-kcsan-gce
2020/10/04 09:16 upstream 22fbc037cd32 5ef9c291 .config console log report info ci2-upstream-kcsan-gce
2020/10/03 20:40 upstream 22fbc037cd32 1a3f9408 .config console log report info ci2-upstream-kcsan-gce
2020/10/02 12:36 upstream 472e5b056f00 9602ddf4 .config console log report info ci2-upstream-kcsan-gce
2020/10/01 08:34 upstream 60e720931556 4103fce0 .config console log report info ci2-upstream-kcsan-gce
2020/09/30 06:41 upstream 02de58b24d2e 8516f6d3 .config console log report info ci2-upstream-kcsan-gce
2020/09/28 22:58 upstream fb0155a09b02 1b88c6d5 .config console log report info ci2-upstream-kcsan-gce
2020/09/27 12:48 upstream a1bffa48745a 5dd8aee8 .config console log report info ci2-upstream-kcsan-gce
2020/09/23 19:01 upstream 805c6d3c1921 54289b08 .config console log report info ci2-upstream-kcsan-gce
2020/09/23 06:15 upstream 805c6d3c1921 3e8f6c27 .config console log report info ci2-upstream-kcsan-gce
2020/09/22 16:44 upstream eff48ddeab78 3e8f6c27 .config console log report info ci2-upstream-kcsan-gce
2020/09/22 08:29 upstream 98477740630f 3e8f6c27 .config console log report info ci2-upstream-kcsan-gce
2020/09/21 21:03 upstream 98477740630f 9e1fa68e .config console log report info ci2-upstream-kcsan-gce
2020/09/20 13:33 upstream 325d0eab4f31 9564d2e9 .config console log report info ci2-upstream-kcsan-gce
2020/09/20 10:29 upstream 325d0eab4f31 53ce8104 .config console log report info ci2-upstream-kcsan-gce
2020/09/20 03:07 upstream 325d0eab4f31 53ce8104 .config console log report info ci2-upstream-kcsan-gce
2020/09/20 00:57 upstream eb5f95f1593f 53ce8104 .config console log report info ci2-upstream-kcsan-gce
2020/07/23 15:42 upstream d15be546031c 70c104a1 .config console log report ci2-upstream-kcsan-gce
2020/06/23 14:31 upstream dd0d718152e4 54566aff .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.