diff options
| author | Michael J. Ruhl <michael.j.ruhl@intel.com> | 2019-02-26 08:45:35 -0800 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@mellanox.com> | 2019-03-06 14:47:09 -0400 |
| commit | bc5add09764c123f58942a37c8335247e683d234 (patch) | |
| tree | a26f32ad5e9f7e0818ccd7400f13f096478f01e5 /drivers/infiniband/hw/hfi1/hfi.h | |
| parent | 0c507d8f846f0158babcc99fc235f17fc79cc2f4 (diff) | |
IB/hfi1: Close race condition on user context disable and close
When disabling and removing a receive context, it is possible for an
asynchronous event (i.e IRQ) to occur. Because of this, there is a race
between cleaning up the context, and the context being used by the
asynchronous event.
cpu 0 (context cleanup)
rc->ref_count-- (ref_count == 0)
hfi1_rcd_free()
cpu 1 (IRQ (with rcd index))
rcd_get_by_index()
lock
ref_count+++ <-- reference count race (WARNING)
return rcd
unlock
cpu 0
hfi1_free_ctxtdata() <-- incorrect free location
lock
remove rcd from array
unlock
free rcd
This race will cause the following WARNING trace:
WARNING: CPU: 0 PID: 175027 at include/linux/kref.h:52 hfi1_rcd_get_by_index+0x84/0xa0 [hfi1]
CPU: 0 PID: 175027 Comm: IMB-MPI1 Kdump: loaded Tainted: G OE ------------ 3.10.0-957.el7.x86_64 #1
Hardware name: Intel Corporation S2600KP/S2600KP, BIOS SE5C610.86B.11.01.0076.C4.111920150602 11/19/2015
Call Trace:
dump_stack+0x19/0x1b
__warn+0xd8/0x100
warn_slowpath_null+0x1d/0x20
hfi1_rcd_get_by_index+0x84/0xa0 [hfi1]
is_rcv_urgent_int+0x24/0x90 [hfi1]
general_interrupt+0x1b6/0x210 [hfi1]
__handle_irq_event_percpu+0x44/0x1c0
handle_irq_event_percpu+0x32/0x80
handle_irq_event+0x3c/0x60
handle_edge_irq+0x7f/0x150
handle_irq+0xe4/0x1a0
do_IRQ+0x4d/0xf0
common_interrupt+0x162/0x162
The race can also lead to a use after free which could be similar to:
general protection fault: 0000 1 SMP
CPU: 71 PID: 177147 Comm: IMB-MPI1 Kdump: loaded Tainted: G W OE ------------ 3.10.0-957.el7.x86_64 #1
Hardware name: Intel Corporation S2600KP/S2600KP, BIOS SE5C610.86B.11.01.0076.C4.111920150602 11/19/2015
task: ffff9962a8098000 ti: ffff99717a508000 task.ti: ffff99717a508000 __kmalloc+0x94/0x230
Call Trace:
? hfi1_user_sdma_process_request+0x9c8/0x1250 [hfi1]
hfi1_user_sdma_process_request+0x9c8/0x1250 [hfi1]
hfi1_aio_write+0xba/0x110 [hfi1]
do_sync_readv_writev+0x7b/0xd0
do_readv_writev+0xce/0x260
? handle_mm_fault+0x39d/0x9b0
? pick_next_task_fair+0x5f/0x1b0
? sched_clock_cpu+0x85/0xc0
? __schedule+0x13a/0x890
vfs_writev+0x35/0x60
SyS_writev+0x7f/0x110
system_call_fastpath+0x22/0x27
Use the appropriate kref API to verify access.
Reorder context cleanup to ensure context removal before cleanup occurs
correctly.
Cc: stable@vger.kernel.org # v4.14.0+
Fixes: f683c80ca68e ("IB/hfi1: Resolve kernel panics by reference counting receive contexts")
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'drivers/infiniband/hw/hfi1/hfi.h')
| -rw-r--r-- | drivers/infiniband/hw/hfi1/hfi.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/infiniband/hw/hfi1/hfi.h b/drivers/infiniband/hw/hfi1/hfi.h index 6582184cc985..048b5d73ba39 100644 --- a/drivers/infiniband/hw/hfi1/hfi.h +++ b/drivers/infiniband/hw/hfi1/hfi.h @@ -1455,7 +1455,7 @@ void hfi1_init_pportdata(struct pci_dev *pdev, struct hfi1_pportdata *ppd, struct hfi1_devdata *dd, u8 hw_pidx, u8 port); void hfi1_free_ctxtdata(struct hfi1_devdata *dd, struct hfi1_ctxtdata *rcd); int hfi1_rcd_put(struct hfi1_ctxtdata *rcd); -void hfi1_rcd_get(struct hfi1_ctxtdata *rcd); +int hfi1_rcd_get(struct hfi1_ctxtdata *rcd); struct hfi1_ctxtdata *hfi1_rcd_get_by_index_safe(struct hfi1_devdata *dd, u16 ctxt); struct hfi1_ctxtdata *hfi1_rcd_get_by_index(struct hfi1_devdata *dd, u16 ctxt); |