From 0b1f6ab68afcf5501294bf8cdd1ac03abf1932e7 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Wed, 8 May 2019 16:00:25 +0200 Subject: [PATCH] 4.14-stable patches added patches: scsi-libsas-fix-a-race-condition-when-smp-task-timeout.patch series --- ...race-condition-when-smp-task-timeout.patch | 65 +++++++++++++++++++ queue-4.14/series | 1 + 2 files changed, 66 insertions(+) create mode 100644 queue-4.14/scsi-libsas-fix-a-race-condition-when-smp-task-timeout.patch create mode 100644 queue-4.14/series diff --git a/queue-4.14/scsi-libsas-fix-a-race-condition-when-smp-task-timeout.patch b/queue-4.14/scsi-libsas-fix-a-race-condition-when-smp-task-timeout.patch new file mode 100644 index 00000000000..562a4557a97 --- /dev/null +++ b/queue-4.14/scsi-libsas-fix-a-race-condition-when-smp-task-timeout.patch @@ -0,0 +1,65 @@ +From b90cd6f2b905905fb42671009dc0e27c310a16ae Mon Sep 17 00:00:00 2001 +From: Jason Yan +Date: Tue, 25 Sep 2018 10:56:54 +0800 +Subject: scsi: libsas: fix a race condition when smp task timeout + +From: Jason Yan + +commit b90cd6f2b905905fb42671009dc0e27c310a16ae upstream. + +When the lldd is processing the complete sas task in interrupt and set the +task stat as SAS_TASK_STATE_DONE, the smp timeout timer is able to be +triggered at the same time. And smp_task_timedout() will complete the task +wheter the SAS_TASK_STATE_DONE is set or not. Then the sas task may freed +before lldd end the interrupt process. Thus a use-after-free will happen. + +Fix this by calling the complete() only when SAS_TASK_STATE_DONE is not +set. And remove the check of the return value of the del_timer(). Once the +LLDD sets DONE, it must call task->done(), which will call +smp_task_done()->complete() and the task will be completed and freed +correctly. + +Reported-by: chenxiang +Signed-off-by: Jason Yan +CC: John Garry +CC: Johannes Thumshirn +CC: Ewan Milne +CC: Christoph Hellwig +CC: Tomas Henzl +CC: Dan Williams +CC: Hannes Reinecke +Reviewed-by: Hannes Reinecke +Reviewed-by: John Garry +Reviewed-by: Johannes Thumshirn +Signed-off-by: Martin K. Petersen +Cc: Guenter Roeck + +--- + drivers/scsi/libsas/sas_expander.c | 9 ++++----- + 1 file changed, 4 insertions(+), 5 deletions(-) + +--- a/drivers/scsi/libsas/sas_expander.c ++++ b/drivers/scsi/libsas/sas_expander.c +@@ -47,17 +47,16 @@ static void smp_task_timedout(unsigned l + unsigned long flags; + + spin_lock_irqsave(&task->task_state_lock, flags); +- if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) ++ if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) { + task->task_state_flags |= SAS_TASK_STATE_ABORTED; ++ complete(&task->slow_task->completion); ++ } + spin_unlock_irqrestore(&task->task_state_lock, flags); +- +- complete(&task->slow_task->completion); + } + + static void smp_task_done(struct sas_task *task) + { +- if (!del_timer(&task->slow_task->timer)) +- return; ++ del_timer(&task->slow_task->timer); + complete(&task->slow_task->completion); + } + diff --git a/queue-4.14/series b/queue-4.14/series new file mode 100644 index 00000000000..e1b7355755a --- /dev/null +++ b/queue-4.14/series @@ -0,0 +1 @@ +scsi-libsas-fix-a-race-condition-when-smp-task-timeout.patch -- 2.39.5