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KCSAN: data-race in inode_update_timestamps / inode_update_timestamps (2)

Status: moderation: reported on 2024/05/15 15:33
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+33da257fe0b2bf79265a@syzkaller.appspotmail.com
First crash: 31d, last: 21d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in inode_update_timestamps / inode_update_timestamps ext4 130 86d 189d 0/27 auto-obsoleted due to no activity on 2024/04/18 13:35

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

write to 0xffff8881064e93d8 of 8 bytes by task 6770 on cpu 1:
 inode_set_mtime_to_ts include/linux/fs.h:1587 [inline]
 inode_update_timestamps+0x16f/0x280 fs/inode.c:1865
 generic_update_time fs/inode.c:1900 [inline]
 inode_update_time fs/inode.c:1920 [inline]
 __file_update_time fs/inode.c:2109 [inline]
 file_modified_flags+0x2a7/0x340 fs/inode.c:2180
 file_modified+0x17/0x20 fs/inode.c:2196
 ext4_dio_write_checks fs/ext4/file.c:485 [inline]
 ext4_dio_write_iter fs/ext4/file.c:551 [inline]
 ext4_file_write_iter+0x8b8/0xe30 fs/ext4/file.c:696
 iter_file_splice_write+0x5e6/0x970 fs/splice.c:743
 do_splice_from fs/splice.c:941 [inline]
 direct_splice_actor+0x16c/0x2c0 fs/splice.c:1164
 splice_direct_to_actor+0x305/0x670 fs/splice.c:1108
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x3ab/0x960 fs/read_write.c:1295
 __do_sys_sendfile64 fs/read_write.c:1362 [inline]
 __se_sys_sendfile64 fs/read_write.c:1348 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1348
 x64_sys_call+0x2c67/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881064e93d8 of 8 bytes by task 6768 on cpu 0:
 inode_get_mtime include/linux/fs.h:1581 [inline]
 inode_update_timestamps+0x8a/0x280 fs/inode.c:1859
 generic_update_time fs/inode.c:1900 [inline]
 inode_update_time fs/inode.c:1920 [inline]
 __file_update_time fs/inode.c:2109 [inline]
 file_modified_flags+0x2a7/0x340 fs/inode.c:2180
 file_modified+0x17/0x20 fs/inode.c:2196
 ext4_dio_write_checks fs/ext4/file.c:485 [inline]
 ext4_dio_write_iter fs/ext4/file.c:551 [inline]
 ext4_file_write_iter+0x8b8/0xe30 fs/ext4/file.c:696
 iter_file_splice_write+0x5e6/0x970 fs/splice.c:743
 do_splice_from fs/splice.c:941 [inline]
 direct_splice_actor+0x16c/0x2c0 fs/splice.c:1164
 splice_direct_to_actor+0x305/0x670 fs/splice.c:1108
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x3ab/0x960 fs/read_write.c:1295
 __do_sys_sendfile64 fs/read_write.c:1362 [inline]
 __se_sys_sendfile64 fs/read_write.c:1348 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1348
 x64_sys_call+0x2c67/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000000206ada75 -> 0x0000000023b7e295

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 6768 Comm: syz-executor.3 Not tainted 6.9.0-syzkaller-12220-g02c438bbfffe #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/25 01:01 upstream 02c438bbfffe a10a183e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in inode_update_timestamps / inode_update_timestamps
2024/05/23 14:13 upstream 2a8120d7b482 4c2072ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in inode_update_timestamps / inode_update_timestamps
2024/05/15 15:33 upstream b850dc206a57 94b087b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in inode_update_timestamps / inode_update_timestamps
* Struck through repros no longer work on HEAD.