Hello,
syzbot found the following crash on:
HEAD commit: f60f0f54 kcsan: Expose core configuration parameters as mo..
git tree:
https://github.com/google/ktsan.git kcsan
console output:
https://syzkaller.appspot.com/x/log.txt?x=15121fcde00000
kernel config:
https://syzkaller.appspot.com/x/.config?x=4b77cdbe9348e50e
dashboard link:
https://syzkaller.appspot.com/bug?extid=14ebd1f92a9a64172cfe
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
CC: [
ak...@linux-foundation.org linux-...@vger.kernel.org linu...@kvack.org el...@google.com]
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+14ebd1...@syzkaller.appspotmail.com
==================================================================
BUG: KCSAN: data-race in __filemap_fdatawrite_range / xas_set_mark
write to 0xffff88812514b3e4 of 4 bytes by task 22468 on cpu 0:
xa_mark_set lib/xarray.c:68 [inline]
xas_set_mark lib/xarray.c:885 [inline]
xas_set_mark+0x14d/0x160 lib/xarray.c:869
tag_pages_for_writeback+0xf4/0x360 mm/page-writeback.c:2114
ext4_writepages+0x91f/0x2500 fs/ext4/inode.c:2708
do_writepages+0x6b/0x170 mm/page-writeback.c:2344
__filemap_fdatawrite_range+0x1c5/0x230 mm/filemap.c:421
file_write_and_wait_range+0xfd/0x160 mm/filemap.c:782
ext4_sync_file+0x266/0xaf0 fs/ext4/fsync.c:153
vfs_fsync_range+0x82/0x150 fs/sync.c:197
generic_write_sync include/linux/fs.h:2856 [inline]
ext4_buffered_write_iter+0x222/0x290 fs/ext4/file.c:259
ext4_file_write_iter+0xf4/0xd40 fs/ext4/file.c:547
call_write_iter include/linux/fs.h:1902 [inline]
do_iter_readv_writev+0x487/0x5b0 fs/read_write.c:693
do_iter_write fs/read_write.c:970 [inline]
do_iter_write+0x13b/0x3c0 fs/read_write.c:951
vfs_iter_write+0x5c/0x80 fs/read_write.c:983
iter_file_splice_write+0x530/0x840 fs/splice.c:760
do_splice_from fs/splice.c:863 [inline]
direct_splice_actor+0xa0/0xc0 fs/splice.c:1037
splice_direct_to_actor+0x22b/0x540 fs/splice.c:992
do_splice_direct+0x161/0x1e0 fs/splice.c:1080
do_sendfile+0x384/0x7f0 fs/read_write.c:1464
__do_sys_sendfile64 fs/read_write.c:1525 [inline]
__se_sys_sendfile64 fs/read_write.c:1511 [inline]
__x64_sys_sendfile64+0x12a/0x140 fs/read_write.c:1511
do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x44/0xa9
read to 0xffff88812514b3e4 of 4 bytes by task 22466 on cpu 1:
mapping_tagged include/linux/fs.h:521 [inline]
__filemap_fdatawrite_range+0x125/0x230 mm/filemap.c:417
file_write_and_wait_range+0xfd/0x160 mm/filemap.c:782
ext4_sync_file+0x266/0xaf0 fs/ext4/fsync.c:153
vfs_fsync_range+0x82/0x150 fs/sync.c:197
generic_write_sync include/linux/fs.h:2856 [inline]
ext4_buffered_write_iter+0x222/0x290 fs/ext4/file.c:259
ext4_file_write_iter+0xf4/0xd40 fs/ext4/file.c:547
call_write_iter include/linux/fs.h:1902 [inline]
do_iter_readv_writev+0x487/0x5b0 fs/read_write.c:693
do_iter_write fs/read_write.c:970 [inline]
do_iter_write+0x13b/0x3c0 fs/read_write.c:951
vfs_iter_write+0x5c/0x80 fs/read_write.c:983
iter_file_splice_write+0x530/0x840 fs/splice.c:760
do_splice_from fs/splice.c:863 [inline]
direct_splice_actor+0xa0/0xc0 fs/splice.c:1037
splice_direct_to_actor+0x22b/0x540 fs/splice.c:992
do_splice_direct+0x161/0x1e0 fs/splice.c:1080
do_sendfile+0x384/0x7f0 fs/read_write.c:1464
__do_sys_sendfile64 fs/read_write.c:1525 [inline]
__se_sys_sendfile64 fs/read_write.c:1511 [inline]
__x64_sys_sendfile64+0x12a/0x140 fs/read_write.c:1511
do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 22466 Comm: syz-executor.3 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
---
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