Hello,
syzbot found the following crash on:
HEAD commit: 7c3cd68e Merge remote-tracking branch 'linux-rcu/kcsan' in..
git tree:
https://github.com/google/ktsan.git kcsan
console output:
https://syzkaller.appspot.com/x/log.txt?x=16016a22100000
kernel config:
https://syzkaller.appspot.com/x/.config?x=ff291dc25f22cdda
dashboard link:
https://syzkaller.appspot.com/bug?extid=ecafdc5c7ccbd3e4f185
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
CC: [
ak...@linux-foundation.org linux-...@vger.kernel.org linu...@kvack.org]
Unfortunately, I don't have any reproducer for this crash yet.
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by:
syzbot+ecafdc...@syzkaller.appspotmail.com
==================================================================
BUG: KCSAN: data-race in __add_to_page_cache_locked / filemap_write_and_wait_range
write to 0xffff88811ec60740 of 8 bytes by task 15924 on cpu 1:
__add_to_page_cache_locked+0x28a/0x800 mm/filemap.c:868
add_to_page_cache_lru+0xc7/0x260 mm/filemap.c:921
ext4_mpage_readpages+0x31c/0x14d0 fs/ext4/readpage.c:259
ext4_readpages+0x8e/0xb0 fs/ext4/inode.c:3243
read_pages+0xa2/0x360 mm/readahead.c:126
__do_page_cache_readahead+0x358/0x380 mm/readahead.c:212
ra_submit mm/internal.h:62 [inline]
ondemand_readahead+0x369/0x730 mm/readahead.c:492
page_cache_sync_readahead+0x1b0/0x1e0 mm/readahead.c:527
generic_file_buffered_read mm/filemap.c:2036 [inline]
generic_file_read_iter+0xf24/0x18c0 mm/filemap.c:2309
ext4_file_read_iter fs/ext4/file.c:131 [inline]
ext4_file_read_iter+0x103/0x360 fs/ext4/file.c:114
call_read_iter include/linux/fs.h:1901 [inline]
generic_file_splice_read+0x2df/0x470 fs/splice.c:313
do_splice_to+0xc7/0x100 fs/splice.c:892
splice_direct_to_actor+0x1b9/0x540 fs/splice.c:971
do_splice_direct+0x152/0x1d0 fs/splice.c:1080
do_sendfile+0x380/0x800 fs/read_write.c:1521
__do_sys_sendfile64 fs/read_write.c:1582 [inline]
__se_sys_sendfile64 fs/read_write.c:1568 [inline]
__x64_sys_sendfile64+0x121/0x140 fs/read_write.c:1568
do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
entry_SYSCALL_64_after_hwframe+0x44/0xa9
read to 0xffff88811ec60740 of 8 bytes by task 15926 on cpu 0:
mapping_needs_writeback mm/filemap.c:632 [inline]
filemap_write_and_wait_range+0x6c/0x140 mm/filemap.c:653
iomap_dio_rw+0x3a2/0x9a0 fs/iomap/direct-io.c:471
ext4_dio_read_iter fs/ext4/file.c:77 [inline]
ext4_file_read_iter fs/ext4/file.c:129 [inline]
ext4_file_read_iter+0x2b4/0x360 fs/ext4/file.c:114
call_read_iter include/linux/fs.h:1901 [inline]
generic_file_splice_read+0x2df/0x470 fs/splice.c:313
do_splice_to+0xc7/0x100 fs/splice.c:892
splice_direct_to_actor+0x1b9/0x540 fs/splice.c:971
do_splice_direct+0x152/0x1d0 fs/splice.c:1080
do_sendfile+0x380/0x800 fs/read_write.c:1521
__do_sys_sendfile64 fs/read_write.c:1582 [inline]
__se_sys_sendfile64 fs/read_write.c:1568 [inline]
__x64_sys_sendfile64+0x121/0x140 fs/read_write.c:1568
do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 15926 Comm: syz-executor.1 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
---
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