Hi Ilia,
On Mon, Oct 20, 2025 at 11:12 AM Ilia Gavrilov Ilia.Gavrilov@infotecs.ru wrote:
In the parse_adv_monitor_pattern() function, the value of the 'length' variable is currently limited to HCI_MAX_EXT_AD_LENGTH(251). The size of the 'value' array in the mgmt_adv_pattern structure is 31. If the value of 'pattern[i].length' is set in the user space and exceeds 31, the 'patterns[i].value' array can be accessed out of bound when copied.
Increasing the size of the 'value' array in the 'mgmt_adv_pattern' structure will break the userspace. Considering this, and to avoid OOB access revert the limits for 'offset' and 'length' back to the value of HCI_MAX_AD_LENGTH.
Found by InfoTeCS on behalf of Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: db08722fc7d4 ("Bluetooth: hci_core: Fix missing instances using HCI_MAX_AD_LENGTH") Cc: stable@vger.kernel.org Signed-off-by: Ilia Gavrilov Ilia.Gavrilov@infotecs.ru
include/net/bluetooth/mgmt.h | 2 +- net/bluetooth/mgmt.c | 6 +++--- 2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/include/net/bluetooth/mgmt.h b/include/net/bluetooth/mgmt.h index 74edea06985b..4b07ce6dfd69 100644 --- a/include/net/bluetooth/mgmt.h +++ b/include/net/bluetooth/mgmt.h @@ -780,7 +780,7 @@ struct mgmt_adv_pattern { __u8 ad_type; __u8 offset; __u8 length;
__u8 value[31];
__u8 value[HCI_MAX_AD_LENGTH];
Why not use HCI_MAX_EXT_AD_LENGTH above? Or perhaps even make it opaque since the actual size is defined by length - offset.
} __packed;
#define MGMT_OP_ADD_ADV_PATTERNS_MONITOR 0x0052 diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c index a3d16eece0d2..500033b70a96 100644 --- a/net/bluetooth/mgmt.c +++ b/net/bluetooth/mgmt.c @@ -5391,9 +5391,9 @@ static u8 parse_adv_monitor_pattern(struct adv_monitor *m, u8 pattern_count, for (i = 0; i < pattern_count; i++) { offset = patterns[i].offset; length = patterns[i].length;
if (offset >= HCI_MAX_EXT_AD_LENGTH ||length > HCI_MAX_EXT_AD_LENGTH ||(offset + length) > HCI_MAX_EXT_AD_LENGTH)
if (offset >= HCI_MAX_AD_LENGTH ||length > HCI_MAX_AD_LENGTH ||(offset + length) > HCI_MAX_AD_LENGTH) return MGMT_STATUS_INVALID_PARAMS; p = kmalloc(sizeof(*p), GFP_KERNEL);-- 2.39.5