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KCSAN: data-race in ext4_mb_free_metadata / ext4_should_retry_alloc

Status: auto-closed as invalid on 2021/11/24 05:46
Subsystems: ext4
[Documentation on labels]
First crash: 911d, last: 911d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in ext4_mb_free_metadata / ext4_should_retry_alloc (3) ext4 1 709d 709d 0/26 closed as invalid on 2022/05/13 11:20
upstream KCSAN: data-race in ext4_mb_free_metadata / ext4_should_retry_alloc (2) ext4 1 851d 851d 0/26 auto-closed as invalid on 2022/01/23 07:11

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ext4_mb_free_metadata / ext4_should_retry_alloc

write to 0xffff8881028e32e4 of 4 bytes by task 10631 on cpu 0:
 ext4_mb_free_metadata+0x3f1/0x470 fs/ext4/mballoc.c:5743
 ext4_free_blocks+0x120b/0x1c20 fs/ext4/mballoc.c:6042
 ext4_remove_blocks+0x61a/0x800 fs/ext4/extents.c:2506
 ext4_ext_rm_leaf+0x684/0xd40 fs/ext4/extents.c:2672
 ext4_ext_remove_space+0x8f6/0x12b0 fs/ext4/extents.c:2920
 ext4_ext_truncate+0xfe/0x170 fs/ext4/extents.c:4382
 ext4_truncate+0x76e/0xa80 fs/ext4/inode.c:4204
 ext4_evict_inode+0xa54/0xdb0 fs/ext4/inode.c:287
 evict+0x1c8/0x3c0 fs/inode.c:588
 iput_final fs/inode.c:1664 [inline]
 iput+0x430/0x580 fs/inode.c:1690
 do_unlinkat+0x2d4/0x540 fs/namei.c:4176
 __do_sys_unlink fs/namei.c:4217 [inline]
 __se_sys_unlink fs/namei.c:4215 [inline]
 __x64_sys_unlink+0x2c/0x30 fs/namei.c:4215
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881028e32e4 of 4 bytes by task 8966 on cpu 1:
 ext4_should_retry_alloc+0xc2/0x170 fs/ext4/balloc.c:655
 ext4_mkdir+0x6ed/0x760 fs/ext4/namei.c:2972
 vfs_mkdir+0x2c3/0x3e0 fs/namei.c:3885
 do_mkdirat+0x12e/0x2c0 fs/namei.c:3911
 __do_sys_mkdir fs/namei.c:3931 [inline]
 __se_sys_mkdir fs/namei.c:3929 [inline]
 __x64_sys_mkdir+0x40/0x50 fs/namei.c:3929
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000855d -> 0x0000962d

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8966 Comm: syz-executor.2 Not tainted 5.15.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/10/20 05:36 upstream d9abdee5fd5a 466b7db1 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in ext4_mb_free_metadata / ext4_should_retry_alloc
* Struck through repros no longer work on HEAD.