From: Phil Turnbull <philipturnbull@xxxxxxxxxx> commit 0cdfa9e6f0915e3d243e2393bfa8a22e12d553b0 upstream. There is no validation of 'e->no_of_channels' which can trigger an out-of-bounds write in the following 'memset' call. Validate that the number of channels does not extends beyond the size of the channel list element. Signed-off-by: Phil Turnbull <philipturnbull@xxxxxxxxxx> Tested-by: Ajay Kathat <ajay.kathat@xxxxxxxxxxxxx> Acked-by: Ajay Kathat <ajay.kathat@xxxxxxxxxxxxx> Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxx> Link: https://lore.kernel.org/r/20221123153543.8568-5-philipturnbull@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/wireless/microchip/wilc1000/cfg80211.c | 23 +++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-) --- a/drivers/net/wireless/microchip/wilc1000/cfg80211.c +++ b/drivers/net/wireless/microchip/wilc1000/cfg80211.c @@ -961,19 +961,30 @@ static inline void wilc_wfi_cfg_parse_ch } if (ch_list_idx) { - u16 attr_size; - struct wilc_ch_list_elem *e; - int i; + unsigned int i; + u16 elem_size; ch_list = (struct wilc_attr_ch_list *)&buf[ch_list_idx]; - attr_size = le16_to_cpu(ch_list->attr_len); - for (i = 0; i < attr_size;) { + /* the number of bytes following the final 'elem' member */ + elem_size = le16_to_cpu(ch_list->attr_len) - + (sizeof(*ch_list) - sizeof(struct wilc_attr_entry)); + for (i = 0; i < elem_size;) { + struct wilc_ch_list_elem *e; + e = (struct wilc_ch_list_elem *)(ch_list->elem + i); + + i += sizeof(*e); + if (i > elem_size) + break; + + i += e->no_of_channels; + if (i > elem_size) + break; + if (e->op_class == WILC_WLAN_OPERATING_CLASS_2_4GHZ) { memset(e->ch_list, sta_ch, e->no_of_channels); break; } - i += e->no_of_channels; } }
