| Message ID | 20210528184502.171731-1-luiz.dentz@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] Bluetooth: MGTM: Fix slab-out-of-bounds in tlv_data_is_valid | expand |
Hi Luiz, > This fixes parsing of LTV entries when the length is 0. > > Found with: > > tools/mgmt-tester -s "Add Advertising - Success (ScRsp only)" > > Add Advertising - Success (ScRsp only) - run > Sending Add Advertising (0x003e) > Test condition added, total 1 > [ 11.004577] ================================================================== > [ 11.005292] BUG: KASAN: slab-out-of-bounds in tlv_data_is_valid+0x87/0xe0 > [ 11.005984] Read of size 1 at addr ffff888002c695b0 by task mgmt-tester/87 > [ 11.006711] > [ 11.007176] > [ 11.007429] Allocated by task 87: > [ 11.008151] > [ 11.008438] The buggy address belongs to the object at ffff888002c69580 > [ 11.008438] which belongs to the cache kmalloc-64 of size 64 > [ 11.010526] The buggy address is located 48 bytes inside of > [ 11.010526] 64-byte region [ffff888002c69580, ffff888002c695c0) > [ 11.012423] The buggy address belongs to the page: > [ 11.013291] > [ 11.013544] Memory state around the buggy address: > [ 11.014359] ffff888002c69480: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > [ 11.015453] ffff888002c69500: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > [ 11.016232] >ffff888002c69580: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc > [ 11.017010] ^ > [ 11.017547] ffff888002c69600: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc > [ 11.018296] ffff888002c69680: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > [ 11.019116] ================================================================== > > Fixes: 2bb36870e8cb2 ("Bluetooth: Unify advertising instance flags check") > Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> > --- > net/bluetooth/mgmt.c | 3 +++ > 1 file changed, 3 insertions(+) patch has been applied to bluetooth-next tree. Regards Marcel
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c index 91d36c3bf23e..b52e39fe0285 100644 --- a/net/bluetooth/mgmt.c +++ b/net/bluetooth/mgmt.c @@ -7590,6 +7590,9 @@ static bool tlv_data_is_valid(struct hci_dev *hdev, u32 adv_flags, u8 *data, for (i = 0, cur_len = 0; i < len; i += (cur_len + 1)) { cur_len = data[i]; + if (!cur_len) + continue; + if (data[i + 1] == EIR_FLAGS && (!is_adv_data || flags_managed(adv_flags))) return false;