KCSAN: data-race in generic_file_buffered_read / ondemand_readahead

Status: auto-closed as invalid on 2021/02/20 07:23
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+f1bfafb19b14137af422@syzkaller.appspotmail.com
First crash: 2227d, last: 2034d

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

write to 0xffff88810ad15db0 of 8 bytes by task 24342 on cpu 1:
 generic_file_buffered_read+0x64c/0x9a0 mm/filemap.c:2540
 generic_file_read_iter+0x80/0x3d0 mm/filemap.c:2633
 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+0x5db/0xca0 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

read to 0xffff88810ad15db0 of 8 bytes by task 24332 on cpu 0:
 ondemand_readahead+0x578/0x780 mm/readahead.c:506
 page_cache_sync_ra+0x1ab/0x1c0 mm/readahead.c:577
 page_cache_sync_readahead include/linux/pagemap.h:839 [inline]
 generic_file_buffered_read_get_pages+0x234/0xaf0 mm/filemap.c:2361
 generic_file_buffered_read+0x27f/0x9a0 mm/filemap.c:2481
 generic_file_read_iter+0x80/0x3d0 mm/filemap.c:2633
 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+0x5db/0xca0 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: 24332 Comm: syz-executor.1 Not tainted 5.11.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (34):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/01/16 07:22 upstream 1d94330a437a 65a7a854 .config console log report info ci2-upstream-kcsan-gce
2020/12/28 18:31 upstream 5c8fe583cce5 8259d56c .config console log report info ci2-upstream-kcsan-gce
2020/12/26 15:33 upstream 40f78232f973 821e0b09 .config console log report info ci2-upstream-kcsan-gce
2020/12/09 12:36 upstream a68a0262abda 99917735 .config console log report info ci2-upstream-kcsan-gce
2020/12/08 21:26 upstream cd796ed33450 40cc414d .config console log report info ci2-upstream-kcsan-gce
2020/11/30 22:14 upstream b65054597872 76831598 .config console log report info ci2-upstream-kcsan-gce
2020/11/11 00:17 upstream eccc87672492 cca87986 .config console log report info ci2-upstream-kcsan-gce
2020/11/04 02:37 upstream 4ef8451b3326 cba33199 .config console log report info ci2-upstream-kcsan-gce
2020/11/03 10:27 upstream b7cbaf59f62f cba33199 .config console log report info ci2-upstream-kcsan-gce
2020/10/29 07:50 upstream 23859ae44402 f24824d3 .config console log report info ci2-upstream-kcsan-gce
2020/10/16 10:50 upstream 9ff9b0d392ea 6e262c73 .config console log report info ci2-upstream-kcsan-gce
2020/10/10 23:06 upstream 6f2f486d57c4 4a77ae0b .config console log report info ci2-upstream-kcsan-gce
2020/10/08 21:52 upstream 3d006ee42dde 92390980 .config console log report info ci2-upstream-kcsan-gce
2020/09/23 08:06 upstream 805c6d3c1921 287cd75a .config console log report info ci2-upstream-kcsan-gce
2020/09/17 18:31 upstream 5925fa68fe82 8247808b .config console log report info ci2-upstream-kcsan-gce
2020/09/16 22:47 upstream 5925fa68fe82 77507d02 .config console log report info ci2-upstream-kcsan-gce
2020/09/11 10:15 upstream 581cb3a26baf adfb8b4e .config console log report ci2-upstream-kcsan-gce
2020/09/05 19:18 upstream 9322c47b21b9 abf9ba4f .config console log report ci2-upstream-kcsan-gce
2020/08/26 12:45 upstream 2ac69819ba9e 318430cb .config console log report ci2-upstream-kcsan-gce
2020/08/19 12:57 upstream 18445bf405cb db787902 .config console log report ci2-upstream-kcsan-gce
2020/08/16 21:45 upstream 2cc3c4b3c2e9 5ce13532 .config console log report ci2-upstream-kcsan-gce
2020/08/15 18:20 upstream 410520d07f5c 5ce13532 .config console log report ci2-upstream-kcsan-gce
2020/08/12 13:19 upstream fb893de323e2 0d7bd2e0 .config console log report ci2-upstream-kcsan-gce
2020/08/12 01:03 upstream bb5baaa9238e bb3e5fe6 .config console log report ci2-upstream-kcsan-gce
2020/08/01 19:01 upstream d52daa8620c6 8df85ed9 .config console log report ci2-upstream-kcsan-gce
2020/07/31 12:32 upstream d8b9faec54ae 8df85ed9 .config console log report ci2-upstream-kcsan-gce
2020/07/30 19:29 upstream 83bdc7275e62 b0947553 .config console log report ci2-upstream-kcsan-gce
2020/07/30 18:56 upstream 83bdc7275e62 b0947553 .config console log report ci2-upstream-kcsan-gce
2020/07/29 02:32 upstream 6ba1b005ffc3 cb93dc6a .config console log report ci2-upstream-kcsan-gce
2020/07/23 13:49 upstream d15be546031c 340ea530 .config console log report ci2-upstream-kcsan-gce
2020/07/22 15:55 upstream 4fa640dc5230 128cd85f .config console log report ci2-upstream-kcsan-gce
2020/07/21 14:34 upstream 4fa640dc5230 e562dd8a .config console log report ci2-upstream-kcsan-gce
2020/07/21 02:19 upstream 4fa640dc5230 d88894e6 .config console log report ci2-upstream-kcsan-gce
2020/07/07 14:06 upstream bfe91da29bfa 42723355 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.