From: Andrei Emeltchenko <andrei.emeltchenko@xxxxxxxxx>
Add extra check to avoid skb buffer overflow. Fixes crash below:
[ 101.030427] ------------[ cut here ]------------
[ 101.030459] kernel BUG at net/core/skbuff.c:127!
[ 101.030486] invalid opcode: 0000 [#1] SMP
...
[ 101.030806] Pid: 2010, comm: btmrvl_main_ser Not tainted 3.5.0+ #80 Laptop
[ 101.030859] EIP: 0060:[<c14f2ba9>] EFLAGS: 00010282 CPU: 0
[ 101.030894] EIP is at skb_put+0x99/0xa0
[ 101.030919] EAX: 00000080 EBX: f129380b ECX: ef923540 EDX: 00000001
[ 101.030956] ESI: f00a4000 EDI: 00001003 EBP: ed4a5efc ESP: ed4a5ecc
[ 101.030992] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[ 101.031024] CR0: 8005003b CR2: 08fca014 CR3: 30960000 CR4: 000407f0
[ 101.031062] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[ 101.031100] DR6: ffff0ff0 DR7: 00000400
[ 101.031125] Process btmrvl_main_ser (pid: 2010, ti=ed4a4000 task=ef923540 task.ti=ed4a4000)
[ 101.031174] Stack:
[ 101.031188] c18126f8 c1651938 f853f8d2 00001003 00001003 f1292800 f1292808 f129380b
[ 101.031250] f1292940 f00a4000 eddb1280 efc0f9c0 ed4a5f44 f853f8d2 00000040 00000000
[ 101.031312] ef923540 c15ee096 ef923540 eddb12d4 00000004 f00a4000 00000040 00000000
[ 101.031376] Call Trace:
[ 101.031396] [<f853f8d2>] ? btmrvl_sdio_process_int_status+0x272/0x3d0 [btmrvl_sdio]
[ 101.031444] [<f853f8d2>] btmrvl_sdio_process_int_status+0x272/0x3d0 [btmrvl_sdio]
[ 101.031488] [<c15ee096>] ? _raw_spin_unlock_irqrestore+0x36/0x70
[ 101.031526] [<f85a46e4>] btmrvl_service_main_thread+0x244/0x300 [btmrvl]
[ 101.031568] [<f853fb50>] ? btmrvl_sdio_poll_card_status.isra.6.constprop.7+0x90/0x90 [btmrvl_sdio]
[ 101.031619] [<c107eda0>] ? try_to_wake_up+0x270/0x270
[ 101.031648] [<f85a44a0>] ? btmrvl_process_event+0x3b0/0x3b0 [btmrvl]
[ 101.031686] [<c106d19d>] kthread+0x7d/0x90
[ 101.031713] [<c106d120>] ? flush_kthread_work+0x150/0x150
[ 101.031745] [<c15f5a82>] kernel_thread_helper+0x6/0x10
...
[ 101.032008] EIP: [<c14f2ba9>] skb_put+0x99/0xa0 SS:ESP 0068:ed4a5ecc
[ 101.056125] ---[ end trace a0bd01d1a9a796c8 ]---
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@xxxxxxxxx>
---
drivers/bluetooth/btmrvl_sdio.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/bluetooth/btmrvl_sdio.c b/drivers/bluetooth/btmrvl_sdio.c
index 1457f25..b3b3680 100644
--- a/drivers/bluetooth/btmrvl_sdio.c
+++ b/drivers/bluetooth/btmrvl_sdio.c
@@ -554,7 +554,16 @@ static int btmrvl_sdio_card_to_host(struct btmrvl_private *priv)
*/
buf_len = payload[0];
- buf_len |= (u16) payload[1] << 8;
+ buf_len |= payload[1] << 8;
+ buf_len |= payload[2] << 16;
+
+ if (buf_len > blksz * num_blocks) {
+ BT_ERR("Skip incorrect packet: hdrlen %d buffer %d",
+ buf_len, blksz * num_blocks);
+ ret = -EIO;
+ goto exit;
+ }
+
type = payload[3];
BT_DBG("%s len %zu type %d", hdev->name, buf_len, type);
--
1.7.9.5
--
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