INFO: task hung in ext4_put_super
Status: upstream: reported C repro on 2021/05/17 11:27
Fix commit: 618f003199c6 ext4: fix memory leak in ext4_fill_super
Patched on: [ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-leak ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce ci-upstream-kmsan-gce-386 ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-qemu2-arm32]
First crash: 105d, last: 45d

Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: KASAN: use-after-free Write in ext4_put_super (log)
Repro: C syz .config

Fix bisection: fixed by (bisect log) :
commit 618f003199c6188e01472b03cdbba227f1dc5f24
Author: Pavel Skripkin <>
Date: Fri Apr 30 18:50:46 2021 +0000

  ext4: fix memory leak in ext4_fill_super

similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in ext4_put_super C 1 7d13h 67d 0/1 upstream: reported C repro on 2021/05/25 03:18
Patch testing requests:
Created Duration User Patch Repo Result
2021/05/17 18:09 19m refs/changes/76/10176/6 OK

Sample crash report:

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-root 2021/04/17 01:41 upstream 2f7b98d1e55c 7e2b734b .config log report syz C INFO: task hung in ext4_put_super