2020-06-06 20:04:25

by Qian Cai

Subject: [PATCH] i40e: silence an UBSAN false positive

virtchnl_rss_lut.lut is used for the RSS lookup table, but in
i40e_vc_config_rss_lut(), it is indexed by subscript results in a false
positive.

UBSAN: array-index-out-of-bounds in drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c:2983:15
index 1 is out of range for type 'u8 [1]'
CPU: 34 PID: 871 Comm: kworker/34:2 Not tainted 5.7.0-next-20200605+ #5
Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 03/09/2018
Workqueue: i40e i40e_service_task [i40e]
Call Trace:
dump_stack+0xa7/0xea
ubsan_epilogue+0x9/0x45
__ubsan_handle_out_of_bounds+0x6f/0x80
i40e_vc_process_vf_msg+0x457c/0x4660 [i40e]
i40e_service_task+0x96c/0x1ab0 [i40e]
process_one_work+0x57d/0xbd0
worker_thread+0x63/0x5b0
kthread+0x20c/0x230
ret_from_fork+0x22/0x30

Fixes: d510497b8397 ("i40e: add input validation for virtchnl handlers")
Signed-off-by: Qian Cai <[email protected]>
---
drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
index 56b9e445732b..d5a959d91ba9 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
@@ -2971,6 +2971,7 @@ static int i40e_vc_config_rss_lut(struct i40e_vf *vf, u8 *msg)
struct i40e_vsi *vsi = NULL;
i40e_status aq_ret = 0;
u16 i;
+ u8 *lut = vrl->lut;

if (!test_bit(I40E_VF_STATE_ACTIVE, &vf->vf_states) ||
!i40e_vc_isvalid_vsi_id(vf, vrl->vsi_id) ||
@@ -2980,13 +2981,13 @@ static int i40e_vc_config_rss_lut(struct i40e_vf *vf, u8 *msg)
}

for (i = 0; i < vrl->lut_entries; i++)
- if (vrl->lut[i] >= vf->num_queue_pairs) {
+ if (lut[i] >= vf->num_queue_pairs) {
aq_ret = I40E_ERR_PARAM;
goto err;
}

vsi = pf->vsi[vf->lan_vsi_idx];
- aq_ret = i40e_config_rss(vsi, NULL, vrl->lut, I40E_VF_HLUT_ARRAY_SIZE);
+ aq_ret = i40e_config_rss(vsi, NULL, lut, I40E_VF_HLUT_ARRAY_SIZE);
/* send the response to the VF */
err:
return i40e_vc_send_resp_to_vf(vf, VIRTCHNL_OP_CONFIG_RSS_LUT,
--
2.21.0 (Apple Git-122.2)

2020-06-11 18:57:05

by Bowers, AndrewX

Subject: RE: [Intel-wired-lan] [PATCH] i40e: silence an UBSAN false positive

> -----Original Message-----
> From: Intel-wired-lan <[email protected]> On Behalf Of
> Qian Cai
> Sent: Saturday, June 6, 2020 1:01 PM
> To: Kirsher, Jeffrey T <[email protected]>
> Cc: [email protected]; [email protected]; Qian Cai
> <[email protected]>; [email protected]; [email protected]
> Subject: [Intel-wired-lan] [PATCH] i40e: silence an UBSAN false positive
>
> virtchnl_rss_lut.lut is used for the RSS lookup table, but in
> i40e_vc_config_rss_lut(), it is indexed by subscript results in a false positive.
>
> UBSAN: array-index-out-of-bounds in
> drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c:2983:15
> index 1 is out of range for type 'u8 [1]'
> CPU: 34 PID: 871 Comm: kworker/34:2 Not tainted 5.7.0-next-20200605+ #5
> Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40
> 03/09/2018
> Workqueue: i40e i40e_service_task [i40e] Call Trace:
> dump_stack+0xa7/0xea
> ubsan_epilogue+0x9/0x45
> __ubsan_handle_out_of_bounds+0x6f/0x80
> i40e_vc_process_vf_msg+0x457c/0x4660 [i40e]
> i40e_service_task+0x96c/0x1ab0 [i40e]
> process_one_work+0x57d/0xbd0
> worker_thread+0x63/0x5b0
> kthread+0x20c/0x230
> ret_from_fork+0x22/0x30
>
> Fixes: d510497b8397 ("i40e: add input validation for virtchnl handlers")
> Signed-off-by: Qian Cai <[email protected]>
> ---
> drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)

Tested-by: Andrew Bowers <[email protected]>