Messages in this thread | | | Date | Tue, 31 Oct 2023 09:28:30 +0000 | From | Martin Habets <> | Subject | Re: [PATCH net-next V2] ptp: fix corrupted list in ptp_open |
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Please use a separate mail thread for a new patch revision. See the section "Resending after review" in Documentation/process/maintainer-netdev.rst.
Martin
On Tue, Oct 31, 2023 at 05:07:08AM +0800, Edward Adam Davis wrote: > There is no lock protection when writing ptp->tsevqs in ptp_open(), > ptp_release(), which can cause data corruption, use mutex lock to avoid this > issue. > > Moreover, ptp_release() should not be used to release the queue in ptp_read(), > and it should be deleted together. > > Reported-and-tested-by: syzbot+df3f3ef31f60781fa911@syzkaller.appspotmail.com > Fixes: 8f5de6fb2453 ("ptp: support multiple timestamp event readers") > Signed-off-by: Edward Adam Davis <eadavis@qq.com> > --- > drivers/ptp/ptp_chardev.c | 11 +++++++++-- > drivers/ptp/ptp_clock.c | 3 +++ > drivers/ptp/ptp_private.h | 1 + > 3 files changed, 13 insertions(+), 2 deletions(-) > > diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c > index 282cd7d24077..e31551d2697d 100644 > --- a/drivers/ptp/ptp_chardev.c > +++ b/drivers/ptp/ptp_chardev.c > @@ -109,6 +109,9 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode) > struct timestamp_event_queue *queue; > char debugfsname[32]; > > + if (mutex_lock_interruptible(&ptp->tsevq_mux)) > + return -ERESTARTSYS; > + > queue = kzalloc(sizeof(*queue), GFP_KERNEL); > if (!queue) > return -EINVAL; > @@ -132,15 +135,20 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode) > debugfs_create_u32_array("mask", 0444, queue->debugfs_instance, > &queue->dfs_bitmap); > > + mutex_unlock(&ptp->tsevq_mux); > return 0; > } > > int ptp_release(struct posix_clock_context *pccontext) > { > struct timestamp_event_queue *queue = pccontext->private_clkdata; > + struct ptp_clock *ptp = > + container_of(pccontext->clk, struct ptp_clock, clock); > unsigned long flags; > > if (queue) { > + if (mutex_lock_interruptible(&ptp->tsevq_mux)) > + return -ERESTARTSYS; > debugfs_remove(queue->debugfs_instance); > pccontext->private_clkdata = NULL; > spin_lock_irqsave(&queue->lock, flags); > @@ -148,6 +156,7 @@ int ptp_release(struct posix_clock_context *pccontext) > spin_unlock_irqrestore(&queue->lock, flags); > bitmap_free(queue->mask); > kfree(queue); > + mutex_unlock(&ptp->tsevq_mux); > } > return 0; > } > @@ -585,7 +594,5 @@ ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags, > free_event: > kfree(event); > exit: > - if (result < 0) > - ptp_release(pccontext); > return result; > } > diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c > index 3d1b0a97301c..7930db6ec18d 100644 > --- a/drivers/ptp/ptp_clock.c > +++ b/drivers/ptp/ptp_clock.c > @@ -176,6 +176,7 @@ static void ptp_clock_release(struct device *dev) > > ptp_cleanup_pin_groups(ptp); > kfree(ptp->vclock_index); > + mutex_destroy(&ptp->tsevq_mux); > mutex_destroy(&ptp->pincfg_mux); > mutex_destroy(&ptp->n_vclocks_mux); > /* Delete first entry */ > @@ -247,6 +248,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, > if (!queue) > goto no_memory_queue; > list_add_tail(&queue->qlist, &ptp->tsevqs); > + mutex_init(&ptp->tsevq_mux); > queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL); > if (!queue->mask) > goto no_memory_bitmap; > @@ -356,6 +358,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, > if (ptp->kworker) > kthread_destroy_worker(ptp->kworker); > kworker_err: > + mutex_destroy(&ptp->tsevq_mux); > mutex_destroy(&ptp->pincfg_mux); > mutex_destroy(&ptp->n_vclocks_mux); > bitmap_free(queue->mask); > diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h > index 52f87e394aa6..1525bd2059ba 100644 > --- a/drivers/ptp/ptp_private.h > +++ b/drivers/ptp/ptp_private.h > @@ -44,6 +44,7 @@ struct ptp_clock { > struct pps_device *pps_source; > long dialed_frequency; /* remembers the frequency adjustment */ > struct list_head tsevqs; /* timestamp fifo list */ > + struct mutex tsevq_mux; /* one process at a time reading the fifo */ > struct mutex pincfg_mux; /* protect concurrent info->pin_config access */ > wait_queue_head_t tsev_wq; > int defunct; /* tells readers to go away when clock is being removed */ > -- > 2.25.1 >
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