Currently cancel_work_sync() is not called when srpt_refresh_port() failed in srpt_add_one(). There is a probability that sdev has been freed while the previously initiated sport->work is still running, leading to a UAF as the log below: [ T880] ib_srpt MAD registration failed for hns_1-1. [ T880] ib_srpt srpt_add_one(hns_1) failed. [ T376] Unable to handle kernel paging request at virtual address 0000000000010008 ... [ T376] Workqueue: events srpt_refresh_port_work [ib_srpt] ... [ T376] Call trace: [ T376] srpt_refresh_port+0x94/0x264 [ib_srpt] [ T376] srpt_refresh_port_work+0x1c/0x2c [ib_srpt] [ T376] process_one_work+0x1d8/0x4cc [ T376] worker_thread+0x158/0x410 [ T376] kthread+0x108/0x13c [ T376] ret_from_fork+0x10/0x18 Add cancel_work_sync() to the exception branch to fix this UAF. Fixes: a42d985bd5b2 ("ib_srpt: Initial SRP Target merge for v3.3-rc1") Signed-off-by: Junxian Huang <huangjunxian6@xxxxxxxxxxxxx> --- drivers/infiniband/ulp/srpt/ib_srpt.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c index 9632afbd727b..244e5c115bf7 100644 --- a/drivers/infiniband/ulp/srpt/ib_srpt.c +++ b/drivers/infiniband/ulp/srpt/ib_srpt.c @@ -3148,8 +3148,8 @@ static int srpt_add_one(struct ib_device *device) { struct srpt_device *sdev; struct srpt_port *sport; + u32 i, j; int ret; - u32 i; pr_debug("device = %p\n", device); @@ -3226,7 +3226,6 @@ static int srpt_add_one(struct ib_device *device) if (ret) { pr_err("MAD registration failed for %s-%d.\n", dev_name(&sdev->device->dev), i); - i--; goto err_port; } } @@ -3241,6 +3240,8 @@ static int srpt_add_one(struct ib_device *device) return 0; err_port: + for (j = i, i--; j > 0; j--) + cancel_work_sync(&sdev->port[j - 1].work); srpt_unregister_mad_agent(sdev, i); err_cm: if (sdev->cm_id) -- 2.33.0