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KCSAN: data-race in ext4_mpage_readpages / ext4_setattr

Status: auto-closed as invalid on 2020/05/12 04:51
Subsystems: ext4
[Documentation on labels]
First crash: 1563d, last: 1487d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in ext4_mpage_readpages / ext4_setattr (4) ext4 5 961d 1000d 0/26 auto-closed as invalid on 2021/09/15 01:54
upstream KCSAN: data-race in ext4_mpage_readpages / ext4_setattr (3) ext4 8 1038d 1085d 0/26 auto-closed as invalid on 2021/06/30 12:56
upstream KCSAN: data-race in ext4_mpage_readpages / ext4_setattr (2) ext4 15 1145d 1208d 0/26 auto-closed as invalid on 2021/03/15 11:12

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ext4_mpage_readpages / ext4_setattr

write to 0xffff8880abe86570 of 8 bytes by task 26514 on cpu 0:
 i_size_write include/linux/fs.h:888 [inline]
 ext4_setattr+0xd58/0x1290 fs/ext4/inode.c:5340
 notify_change+0x82b/0xb00 fs/attr.c:336
 do_truncate+0xf9/0x180 fs/open.c:64
 handle_truncate fs/namei.c:3083 [inline]
 do_last fs/namei.c:3496 [inline]
 path_openat+0x1241/0x2f70 fs/namei.c:3607
 do_filp_open+0x11e/0x1b0 fs/namei.c:3637
 do_sys_openat2+0x4f5/0x620 fs/open.c:1149
 do_sys_open+0xa2/0x110 fs/open.c:1165
 ksys_open include/linux/syscalls.h:1386 [inline]
 __do_sys_creat fs/open.c:1233 [inline]
 __se_sys_creat fs/open.c:1231 [inline]
 __x64_sys_creat+0x42/0x60 fs/open.c:1231
 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880abe86570 of 8 bytes by task 26488 on cpu 1:
 ext4_readpage_limit fs/ext4/readpage.c:221 [inline]
 ext4_mpage_readpages+0x52d/0x1400 fs/ext4/readpage.c:269
 ext4_readpages+0x8e/0xb0 fs/ext4/inode.c:3245
 read_pages+0xa2/0x2d0 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_async_readahead+0x237/0x260 mm/readahead.c:574
 generic_file_buffered_read mm/filemap.c:2037 [inline]
 generic_file_read_iter+0xff2/0x1490 mm/filemap.c:2302
 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:1895 [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+0x396/0x810 fs/read_write.c:1520
 __do_sys_sendfile64 fs/read_write.c:1581 [inline]
 __se_sys_sendfile64 fs/read_write.c:1567 [inline]
 __x64_sys_sendfile64+0x121/0x140 fs/read_write.c:1567
 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 26488 Comm: syz-executor.3 Not tainted 5.6.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/03/03 04:48 https://github.com/google/ktsan.git kcsan 766d004d1b85 4a4e0509 .config console log report ci2-upstream-kcsan-gce
2020/02/12 03:48 https://github.com/google/ktsan.git kcsan f60f0f543333 4d1ab643 .config console log report ci2-upstream-kcsan-gce
2019/12/18 11:48 https://github.com/google/ktsan.git kcsan 245a43005292 64ca0a37 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.