linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: syzbot <syzbot+0f1e470df6a4316e0a11@syzkaller.appspotmail.com>
To: akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
	 linux-mm@kvack.org, syzkaller-bugs@googlegroups.com
Subject: KCSAN: data-race in generic_file_buffered_read / generic_file_buffered_read
Date: Wed, 15 Jul 2020 08:16:25 -0700	[thread overview]
Message-ID: <0000000000004a4d6505aa7c688a@google.com> (raw)

Hello,

syzbot found the following issue on:

HEAD commit:    e9919e11 Merge branch 'for-linus' of git://git.kernel.org/..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1217a83b100000
kernel config:  https://syzkaller.appspot.com/x/.config?x=570eb530a65cd98e
dashboard link: https://syzkaller.appspot.com/bug?extid=0f1e470df6a4316e0a11
compiler:       clang version 11.0.0 (https://github.com/llvm/llvm-project.git ca2dcbd030eadbf0aa9b660efe864ff08af6e18b)

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0f1e470df6a4316e0a11@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in generic_file_buffered_read / generic_file_buffered_read

write to 0xffff8880968747b0 of 8 bytes by task 6336 on cpu 0:
 generic_file_buffered_read+0x18be/0x19e0 mm/filemap.c:2246
 generic_file_read_iter+0x7d/0x3e0 mm/filemap.c:2326
 ext4_file_read_iter+0x2d6/0x420 fs/ext4/file.c:74
 call_read_iter include/linux/fs.h:1902 [inline]
 generic_file_splice_read+0x22a/0x310 fs/splice.c:312
 do_splice_to fs/splice.c:870 [inline]
 splice_direct_to_actor+0x2a8/0x660 fs/splice.c:950
 do_splice_direct+0xf2/0x170 fs/splice.c:1059
 do_sendfile+0x562/0xb10 fs/read_write.c:1540
 __do_sys_sendfile64 fs/read_write.c:1601 [inline]
 __se_sys_sendfile64 fs/read_write.c:1587 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1587
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880968747b0 of 8 bytes by task 6334 on cpu 1:
 generic_file_buffered_read+0x11e/0x19e0 mm/filemap.c:2011
 generic_file_read_iter+0x7d/0x3e0 mm/filemap.c:2326
 ext4_file_read_iter+0x2d6/0x420 fs/ext4/file.c:74
 call_read_iter include/linux/fs.h:1902 [inline]
 generic_file_splice_read+0x22a/0x310 fs/splice.c:312
 do_splice_to fs/splice.c:870 [inline]
 splice_direct_to_actor+0x2a8/0x660 fs/splice.c:950
 do_splice_direct+0xf2/0x170 fs/splice.c:1059
 do_sendfile+0x562/0xb10 fs/read_write.c:1540
 __do_sys_sendfile64 fs/read_write.c:1601 [inline]
 __se_sys_sendfile64 fs/read_write.c:1587 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1587
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 6334 Comm: syz-executor.0 Not tainted 5.8.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.


             reply	other threads:[~2020-07-15 15:16 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-15 15:16 syzbot [this message]
2020-07-15 15:29 ` KCSAN: data-race in generic_file_buffered_read / generic_file_buffered_read Marco Elver
2020-07-15 16:32   ` Eric Biggers
2020-07-15 16:45     ` Marco Elver
2020-07-15 23:42     ` Dave Chinner
2020-07-16  3:03       ` Eric Biggers
2020-07-16  6:24         ` Nicholas Piggin
2020-07-16  6:54           ` Eric Biggers
2020-07-16  7:52             ` Nicholas Piggin
2020-07-16 12:56               ` Marco Elver
2020-07-16 13:19             ` Matthew Wilcox

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=0000000000004a4d6505aa7c688a@google.com \
    --to=syzbot+0f1e470df6a4316e0a11@syzkaller.appspotmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=syzkaller-bugs@googlegroups.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).