syzbot
panic: nested locking: kernel.taskSetRWMutex: (3)
Status: fixed on 2026/05/08 08:36
Fix commit:
8c2aa261c278
pidfds: Disallow fasync on pidfds
First crash: 180d, last: 180d
Sample crash report:
panic: nested locking: kernel.taskSetRWMutex:
goroutine 445 [running]:
gvisor.dev/gvisor/pkg/sentry/kernel.(*taskSetRWMutex).RLock(0xc000018320)
/syzkaller/.cache/bazel/_bazel_root/a13edd57d9dad04937e1fb5843ea1532/sandbox/linux-sandbox/9/execroot/_main/gopath/src/gvisor.dev/gvisor/pkg/sentry/kernel/taskset_mutex.go:59 +0x98
gvisor.dev/gvisor/pkg/sentry/kernel.(*ThreadGroup).Leader(0xc0012b9808)
/syzkaller/.cache/bazel/_bazel_root/a13edd57d9dad04937e1fb5843ea1532/sandbox/linux-sandbox/9/execroot/_main/gopath/src/gvisor.dev/gvisor/pkg/sentry/kernel/threads.go:484 +0xb4
gvisor.dev/gvisor/pkg/sentry/kernel/fasync.(*FileAsync).NotifyEvent(0xc0002ca9a0, 0x41)
/syzkaller/.cache/bazel/_bazel_root/a13edd57d9dad04937e1fb5843ea1532/sandbox/linux-sandbox/9/execroot/_main/gopath/src/gvisor.dev/gvisor/pkg/sentry/kernel/fasync/fasync.go:107 +0x2b2
gvisor.dev/gvisor/pkg/waiter.(*Queue).Notify(0xc001063bd0, 0x41)
/syzkaller/.cache/bazel/_bazel_root/a13edd57d9dad04937e1fb5843ea1532/sandbox/linux-sandbox/9/execroot/_main/gopath/src/gvisor.dev/gvisor/pkg/waiter/waiter.go:253 +0x13d
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).notifyPIDFDsLocked(0xc001314c88)
/syzkaller/.cache/bazel/_bazel_root/a13edd57d9dad04937e1fb5843ea1532/sandbox/linux-sandbox/9/execroot/_main/gopath/src/gvisor.dev/gvisor/pkg/sentry/kernel/pidfd.go:281 +0xed
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).exitNotifyLocked(0xc001314c88, 0x0)
/syzkaller/.cache/bazel/_bazel_root/a13edd57d9dad04937e1fb5843ea1532/sandbox/linux-sandbox/9/execroot/_main/gopath/src/gvisor.dev/gvisor/pkg/sentry/kernel/task_exit.go:655 +0x19b
gvisor.dev/gvisor/pkg/sentry/kernel.(*runExitNotify).execute(0xc001314c88?, 0xc001314c88)
/syzkaller/.cache/bazel/_bazel_root/a13edd57d9dad04937e1fb5843ea1532/sandbox/linux-sandbox/9/execroot/_main/gopath/src/gvisor.dev/gvisor/pkg/sentry/kernel/task_exit.go:634 +0x3bd
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0xc001314c88, 0x4d)
/syzkaller/.cache/bazel/_bazel_root/a13edd57d9dad04937e1fb5843ea1532/sandbox/linux-sandbox/9/execroot/_main/gopath/src/gvisor.dev/gvisor/pkg/sentry/kernel/task_run.go:89 +0x6e7
created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start in goroutine 546
/syzkaller/.cache/bazel/_bazel_root/a13edd57d9dad04937e1fb5843ea1532/sandbox/linux-sandbox/9/execroot/_main/gopath/src/gvisor.dev/gvisor/pkg/sentry/kernel/task_start.go:416 +0x1be
* Struck through repros no longer work on HEAD.