kmemdup() at line 2735 is not duplicating enough memory for
notif->tid_tear_down and notif->station_id. As it only duplicates
612 bytes: up to offsetofend(struct iwl_wowlan_info_notif,
received_beacons), this is the range of [0, 612) bytes.
2735 notif = kmemdup(notif_v1,
2736 offsetofend(struct iwl_wowlan_info_notif,
2737 received_beacons),
2738 GFP_ATOMIC);
which evidently does not cover bytes 612 and 613 for members
tid_tear_down and station_id in struct iwl_wowlan_info_notif.
See below:
$ pahole -C iwl_wowlan_info_notif drivers/net/wireless/intel/iwlwifi/mvm/d3.o
struct iwl_wowlan_info_notif {
struct iwl_wowlan_gtk_status_v3 gtk[2]; /* 0 488 */
/* --- cacheline 7 boundary (448 bytes) was 40 bytes ago --- */
struct iwl_wowlan_igtk_status igtk[2]; /* 488 80 */
/* --- cacheline 8 boundary (512 bytes) was 56 bytes ago --- */
__le64 replay_ctr; /* 568 8 */
/* --- cacheline 9 boundary (576 bytes) --- */
__le16 pattern_number; /* 576 2 */
__le16 reserved1; /* 578 2 */
__le16 qos_seq_ctr[8]; /* 580 16 */
__le32 wakeup_reasons; /* 596 4 */
__le32 num_of_gtk_rekeys; /* 600 4 */
__le32 transmitted_ndps; /* 604 4 */
__le32 received_beacons; /* 608 4 */
u8 tid_tear_down; /* 612 1 */
u8 station_id; /* 613 1 */
u8 reserved2[2]; /* 614 2 */
/* size: 616, cachelines: 10, members: 13 */
/* last cacheline: 40 bytes */
};
Therefore, when the following assignments take place, actually no memory
has been allocated for those objects:
2743 notif->tid_tear_down = notif_v1->tid_tear_down;
2744 notif->station_id = notif_v1->station_id;
Fix this by allocating space for the whole notif object and zero out the
remaining space in memory after member station_id.
This also fixes the following -Warray-bounds issues:
CC drivers/net/wireless/intel/iwlwifi/mvm/d3.o
drivers/net/wireless/intel/iwlwifi/mvm/d3.c: In function ‘iwl_mvm_wait_d3_notif’:
drivers/net/wireless/intel/iwlwifi/mvm/d3.c:2743:30: warning: array subscript ‘struct iwl_wowlan_info_notif[0]’ is partly outside array bounds of ‘unsigned char[612]’ [-Warray-bounds=]
2743 | notif->tid_tear_down = notif_v1->tid_tear_down;
|
from drivers/net/wireless/intel/iwlwifi/mvm/d3.c:7:
In function ‘kmemdup’,
inlined from ‘iwl_mvm_wait_d3_notif’ at drivers/net/wireless/intel/iwlwifi/mvm/d3.c:2735:12:
include/linux/fortify-string.h:765:16: note: object of size 612 allocated by ‘__real_kmemdup’
765 | return __real_kmemdup(p, size, gfp);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/wireless/intel/iwlwifi/mvm/d3.c: In function ‘iwl_mvm_wait_d3_notif’:
drivers/net/wireless/intel/iwlwifi/mvm/d3.c:2744:30: warning: array subscript ‘struct iwl_wowlan_info_notif[0]’ is partly outside array bounds of ‘unsigned char[612]’ [-Warray-bounds=]
2744 | notif->station_id = notif_v1->station_id;
| ^~
In function ‘kmemdup’,
inlined from ‘iwl_mvm_wait_d3_notif’ at drivers/net/wireless/intel/iwlwifi/mvm/d3.c:2735:12:
include/linux/fortify-string.h:765:16: note: object of size 612 allocated by ‘__real_kmemdup’
765 | return __real_kmemdup(p, size, gfp);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
Link: https://github.com/KSPP/linux/issues/306
Fixes: 905d50ddbc83 ("wifi: iwlwifi: mvm: support wowlan info notification version 2")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
---
Changes in v2:
- Use sizeof(*notif), instead of sizeof(struct iwl_wowlan_info_notif).
- Fix typo in the changelog text s/bouds/bounds.
v1:
- Link: https://lore.kernel.org/linux-hardening/ZHpEjTmBys5cCOGZ@work/
drivers/net/wireless/intel/iwlwifi/mvm/d3.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/d3.c b/drivers/net/wireless/intel/iwlwifi/mvm/d3.c
index 37aa4676dc94..6d1007f24b4a 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/d3.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/d3.c
@@ -2732,17 +2732,13 @@ static bool iwl_mvm_wait_d3_notif(struct iwl_notif_wait_data *notif_wait,
if (wowlan_info_ver < 2) {
struct iwl_wowlan_info_notif_v1 *notif_v1 = (void *)pkt->data;
- notif = kmemdup(notif_v1,
- offsetofend(struct iwl_wowlan_info_notif,
- received_beacons),
- GFP_ATOMIC);
-
+ notif = kmemdup(notif_v1, sizeof(*notif), GFP_ATOMIC);
if (!notif)
return false;
notif->tid_tear_down = notif_v1->tid_tear_down;
notif->station_id = notif_v1->station_id;
-
+ memset_after(notif, 0, station_id);
} else {
notif = (void *)pkt->data;
}
--
2.34.1
