| Message ID | tencent_856E1C97CCE9E2ED66CC087B526CD42ED50A@qq.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next,V6] ptp: fix corrupted list in ptp_open | expand |
Edward! On Sun, Nov 05, 2023 at 10:12:08AM +0800, Edward Adam Davis wrote: > There is no lock protection when writing ptp->tsevqs in ptp_open() and > ptp_release(), which can cause data corruption, use spin 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. Change to: "it should be deleted altogether" > 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 | 1 + > drivers/ptp/ptp_private.h | 1 + > 3 files changed, 9 insertions(+), 4 deletions(-) > > diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c > index 282cd7d24077..31594f40a21e 100644 > --- a/drivers/ptp/ptp_chardev.c > +++ b/drivers/ptp/ptp_chardev.c > @@ -108,6 +108,7 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode) > container_of(pccontext->clk, struct ptp_clock, clock); > struct timestamp_event_queue *queue; > char debugfsname[32]; > + unsigned long flags; > > queue = kzalloc(sizeof(*queue), GFP_KERNEL); > if (!queue) > @@ -119,8 +120,10 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode) > } > bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS); > spin_lock_init(&queue->lock); > + spin_lock_irqsave(&ptp->tsevqs_lock, flags); > list_add_tail(&queue->qlist, &ptp->tsevqs); > pccontext->private_clkdata = queue; Move this assignment outside of locked region, i.e. after spin_unlock_irqrestore(). > + spin_unlock_irqrestore(&ptp->tsevqs_lock, flags); > > /* Debugfs contents */ > sprintf(debugfsname, "0x%p", queue); > @@ -139,13 +142,15 @@ int ptp_release(struct posix_clock_context *pccontext) > { > struct timestamp_event_queue *queue = pccontext->private_clkdata; > unsigned long flags; > + struct ptp_clock *ptp = > + container_of(pccontext->clk, struct ptp_clock, clock); > > if (queue) { Please remove this test. Since you removed ptp_release() from ptp_read(), the queue cannot be NULL. > debugfs_remove(queue->debugfs_instance); > + spin_lock_irqsave(&ptp->tsevqs_lock, flags); > pccontext->private_clkdata = NULL; Move this assignment outside of locked region. > - spin_lock_irqsave(&queue->lock, flags); > list_del(&queue->qlist); > - spin_unlock_irqrestore(&queue->lock, flags); > + spin_unlock_irqrestore(&ptp->tsevqs_lock, flags); > bitmap_free(queue->mask); > kfree(queue); > } > @@ -585,7 +590,5 @@ ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags, > free_event: > kfree(event); > exit: > - if (result < 0) > - ptp_release(pccontext); This is good, but please put it into a separate patch, along with the removal of the bogus "if (queue)" test in ptp_release(). > return result; > } > diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c > index 3d1b0a97301c..ea82648ad557 100644 > --- a/drivers/ptp/ptp_clock.c > +++ b/drivers/ptp/ptp_clock.c > @@ -247,6 +247,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, > if (!queue) > goto no_memory_queue; > list_add_tail(&queue->qlist, &ptp->tsevqs); > + spin_lock_init(&ptp->tsevqs_lock); > queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL); > if (!queue->mask) > goto no_memory_bitmap; > diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h > index 52f87e394aa6..63af246f17eb 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 */ > + spinlock_t tsevqs_lock; /* one process at a time writing the timestamp fifo list*/ Please change this comment to "protects tsevqs from concurrent access" > 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 > Since v6.6 now contains the original commit, please change subject to [net]. Thanks, Richard
On Sun, Nov 05, 2023 at 05:36:41AM -0800, Richard Cochran wrote: > > @@ -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 */ > > + spinlock_t tsevqs_lock; /* one process at a time writing the timestamp fifo list*/ > > Please change this comment to "protects tsevqs from concurrent access" And please don't forget to take the spin lock around list_for_each_entry() in ptp_clock_event(). Thanks, Richard
diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c index 282cd7d24077..31594f40a21e 100644 --- a/drivers/ptp/ptp_chardev.c +++ b/drivers/ptp/ptp_chardev.c @@ -108,6 +108,7 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode) container_of(pccontext->clk, struct ptp_clock, clock); struct timestamp_event_queue *queue; char debugfsname[32]; + unsigned long flags; queue = kzalloc(sizeof(*queue), GFP_KERNEL); if (!queue) @@ -119,8 +120,10 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode) } bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS); spin_lock_init(&queue->lock); + spin_lock_irqsave(&ptp->tsevqs_lock, flags); list_add_tail(&queue->qlist, &ptp->tsevqs); pccontext->private_clkdata = queue; + spin_unlock_irqrestore(&ptp->tsevqs_lock, flags); /* Debugfs contents */ sprintf(debugfsname, "0x%p", queue); @@ -139,13 +142,15 @@ int ptp_release(struct posix_clock_context *pccontext) { struct timestamp_event_queue *queue = pccontext->private_clkdata; unsigned long flags; + struct ptp_clock *ptp = + container_of(pccontext->clk, struct ptp_clock, clock); if (queue) { debugfs_remove(queue->debugfs_instance); + spin_lock_irqsave(&ptp->tsevqs_lock, flags); pccontext->private_clkdata = NULL; - spin_lock_irqsave(&queue->lock, flags); list_del(&queue->qlist); - spin_unlock_irqrestore(&queue->lock, flags); + spin_unlock_irqrestore(&ptp->tsevqs_lock, flags); bitmap_free(queue->mask); kfree(queue); } @@ -585,7 +590,5 @@ 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..ea82648ad557 100644 --- a/drivers/ptp/ptp_clock.c +++ b/drivers/ptp/ptp_clock.c @@ -247,6 +247,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, if (!queue) goto no_memory_queue; list_add_tail(&queue->qlist, &ptp->tsevqs); + spin_lock_init(&ptp->tsevqs_lock); queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL); if (!queue->mask) goto no_memory_bitmap; diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h index 52f87e394aa6..63af246f17eb 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 */ + spinlock_t tsevqs_lock; /* one process at a time writing the timestamp fifo list*/ 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 */
There is no lock protection when writing ptp->tsevqs in ptp_open() and ptp_release(), which can cause data corruption, use spin 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 | 1 + drivers/ptp/ptp_private.h | 1 + 3 files changed, 9 insertions(+), 4 deletions(-)