On 17/09/24 20:10, Jeff Johnson wrote:
On 9/17/2024 8:08 AM, Alper Nebi Yasak wrote:
Replace one-element array with a flexible-array member in `struct
mwifiex_ie_types_wildcard_ssid_params` to fix the following warning
on a MT8173 Chromebook (mt8173-elm-hana):
[ 356.775250] ------------[ cut here ]------------
[ 356.784543] memcpy: detected field-spanning write (size 6) of single field "wildcard_ssid_tlv->ssid" at drivers/net/wireless/marvell/mwifiex/scan.c:904 (size 1)
[ 356.813403] WARNING: CPU: 3 PID: 742 at drivers/net/wireless/marvell/mwifiex/scan.c:904 mwifiex_scan_networks+0x4fc/0xf28 [mwifiex]
The "(size 6)" above is exactly the length of the SSID of the network
this device was connected to. The source of the warning looks like:
ssid_len = user_scan_in->ssid_list[i].ssid_len;
[...]
memcpy(wildcard_ssid_tlv->ssid,
user_scan_in->ssid_list[i].ssid, ssid_len);
Also adjust a #define that uses sizeof() on this struct to keep the
value same as before.
Signed-off-by: Alper Nebi Yasak <alpernebiyasak@xxxxxxxxx>
---
I found these relevant patches that modify other such arrays, where the
second one removes a -1 from some sizeof() calculation:
https://lore.kernel.org/lkml/Y9xkECG3uTZ6T1dN@work/T/#u
https://lore.kernel.org/lkml/ZsZa5xRcsLq9D+RX@elsanto/T/#u
So I think we need the +1 to keep things same. But it appears to work
fine without it, so I'm not sure. Maybe it should've had a -1 before
that I would remove with this?
I think the original code was incorrect and was allocating too much memory.
I do not think WILDCARD_SSID_TLV_MAX_SIZE requires modification.
If this is case, I think the changelog text should include the following
'Fixes' tag (and the `__counted_by` annotation added in a separate patch):
Fixes: 5e6e3a92b9a4 ("wireless: mwifiex: initial commit for Marvell mwifiex driver")
Thanks
--
Gustavo
drivers/net/wireless/marvell/mwifiex/fw.h | 2 +-
drivers/net/wireless/marvell/mwifiex/scan.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/marvell/mwifiex/fw.h b/drivers/net/wireless/marvell/mwifiex/fw.h
index d03129d5d24e..4a96281792cc 100644
--- a/drivers/net/wireless/marvell/mwifiex/fw.h
+++ b/drivers/net/wireless/marvell/mwifiex/fw.h
@@ -875,7 +875,7 @@ struct mwifiex_ietypes_chanstats {
struct mwifiex_ie_types_wildcard_ssid_params {
struct mwifiex_ie_types_header header;
u8 max_ssid_length;
- u8 ssid[1];
+ u8 ssid[];
} __packed;
#define TSF_DATA_SIZE 8
diff --git a/drivers/net/wireless/marvell/mwifiex/scan.c b/drivers/net/wireless/marvell/mwifiex/scan.c
index cab889af4c4a..50af78ee935b 100644
--- a/drivers/net/wireless/marvell/mwifiex/scan.c
+++ b/drivers/net/wireless/marvell/mwifiex/scan.c
@@ -32,7 +32,7 @@
#define WILDCARD_SSID_TLV_MAX_SIZE \
(MWIFIEX_MAX_SSID_LIST_LENGTH * \
(sizeof(struct mwifiex_ie_types_wildcard_ssid_params) \
- + IEEE80211_MAX_SSID_LEN))
+ + IEEE80211_MAX_SSID_LEN + 1))
/* Maximum memory needed for a mwifiex_scan_cmd_config with all TLVs at max */
#define MAX_SCAN_CFG_ALLOC (sizeof(struct mwifiex_scan_cmd_config) \
base-commit: 4f3e012d4cfd1d9bf837870c961f462ca9f23ebe
