diff options
| author | Duoming Zhou <duoming@zju.edu.cn> | 2025-08-28 16:29:49 +0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-08-29 19:10:22 -0700 |
| commit | 8bf935cf789872350b04c1a6468b0a509f67afb2 (patch) | |
| tree | 50902684573c2c0de5ce4820bbbe584e6d6ea5b2 | |
| parent | b79e498080b170fd94fc83bca2471f450811549b (diff) | |
ptp: ocp: fix use-after-free bugs causing by ptp_ocp_watchdog
The ptp_ocp_detach() only shuts down the watchdog timer if it is
pending. However, if the timer handler is already running, the
timer_delete_sync() is not called. This leads to race conditions
where the devlink that contains the ptp_ocp is deallocated while
the timer handler is still accessing it, resulting in use-after-free
bugs. The following details one of the race scenarios.
(thread 1) | (thread 2)
ptp_ocp_remove() |
ptp_ocp_detach() | ptp_ocp_watchdog()
if (timer_pending(&bp->watchdog))| bp = timer_container_of()
timer_delete_sync() |
|
devlink_free(devlink) //free |
| bp-> //use
Resolve this by unconditionally calling timer_delete_sync() to ensure
the timer is reliably deactivated, preventing any access after free.
Fixes: 773bda964921 ("ptp: ocp: Expose various resources on the timecard.")
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://patch.msgid.link/20250828082949.28189-1-duoming@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/ptp/ptp_ocp.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c index d39073dc4072..4e1286ce05c9 100644 --- a/drivers/ptp/ptp_ocp.c +++ b/drivers/ptp/ptp_ocp.c @@ -4557,8 +4557,7 @@ ptp_ocp_detach(struct ptp_ocp *bp) ptp_ocp_debugfs_remove_device(bp); ptp_ocp_detach_sysfs(bp); ptp_ocp_attr_group_del(bp); - if (timer_pending(&bp->watchdog)) - timer_delete_sync(&bp->watchdog); + timer_delete_sync(&bp->watchdog); if (bp->ts0) ptp_ocp_unregister_ext(bp->ts0); if (bp->ts1) |