* [PATCH] Bluetooth: hci_intel: prevent reads beyond the end of skb->data
@ 2021-05-27 13:03 Dan Carpenter
2021-05-27 13:55 ` bluez.test.bot
2021-05-27 15:19 ` [PATCH] " Marcel Holtmann
0 siblings, 2 replies; 4+ messages in thread
From: Dan Carpenter @ 2021-05-27 13:03 UTC (permalink / raw)
To: Marcel Holtmann, Loic Poulain, Luiz Augusto von Dentz
Cc: Johan Hedberg, Loic Poulain, linux-bluetooth, kernel-janitors
There doesn't appear to be any checks to ensure that skb->data is large
enough in these functions. For most of these, if we specify a header
length, then h4_recv_buf() will ensure that all packets are at least the
minimum length. The intel_recv_lpm() function needs an additional
check for LPM_OP_TX_NOTIFY packets.
Fixes: ca93cee5a56e ("Bluetooth: hci_uart: Add basic support for Intel Lightning Peak devices")
No signed-off-by because I can't test this and just wanted to collect
feedback. This is part of a static checker warning because someone
reported the hci_event.c read overflows to security@kernel.org. This
stuff is quite complicated for static checkers of course and I don't
understand all the rules yet. Right now I have about 2000 warnings
that look like this:
drivers/bluetooth/hci_intel.c:877 intel_recv_event() warn: assignment assumes 'skb->len' is '2' bytes
drivers/bluetooth/hci_intel.c:922 intel_recv_lpm() warn: assignment assumes 'skb->len' is '2' bytes
drivers/bluetooth/hci_intel.c:1028 intel_dequeue() warn: assignment assumes 'skb->len' is '3' bytes
I think there should be a different additional static checker warning
for h4_recv_pkt structs like in this patch if you fail to specify a
.hlen value?
regards,
dan carpenter
---
drivers/bluetooth/hci_intel.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/bluetooth/hci_intel.c b/drivers/bluetooth/hci_intel.c
index 7249b91d9b91..3e4bccacad9b 100644
--- a/drivers/bluetooth/hci_intel.c
+++ b/drivers/bluetooth/hci_intel.c
@@ -925,7 +925,7 @@ static int intel_recv_lpm(struct hci_dev *hdev, struct sk_buff *skb)
switch (lpm->opcode) {
case LPM_OP_TX_NOTIFY:
- if (lpm->dlen < 1) {
+ if (lpm->dlen < 1 || skb->len < struct_size(lpm, data, 1)) {
bt_dev_err(hu->hdev, "Invalid LPM notification packet");
break;
}
@@ -959,10 +959,10 @@ static int intel_recv_lpm(struct hci_dev *hdev, struct sk_buff *skb)
.maxlen = HCI_LPM_MAX_SIZE
static const struct h4_recv_pkt intel_recv_pkts[] = {
- { H4_RECV_ACL, .recv = hci_recv_frame },
- { H4_RECV_SCO, .recv = hci_recv_frame },
- { H4_RECV_EVENT, .recv = intel_recv_event },
- { INTEL_RECV_LPM, .recv = intel_recv_lpm },
+ { H4_RECV_ACL, .recv = hci_recv_frame, .hlen = sizeof(struct bt_skb_cb) },
+ { H4_RECV_SCO, .recv = hci_recv_frame, .hlen = sizeof(struct bt_skb_cb) },
+ { H4_RECV_EVENT, .recv = intel_recv_event, .hlen = sizeof(struct hci_event_hdr) },
+ { INTEL_RECV_LPM, .recv = intel_recv_lpm, .hlen = sizeof(struct hci_lpm_pkt) },
};
static int intel_recv(struct hci_uart *hu, const void *data, int count)
--
2.30.2
^ permalink raw reply related [flat|nested] 4+ messages in thread
* RE: Bluetooth: hci_intel: prevent reads beyond the end of skb->data
2021-05-27 13:03 [PATCH] Bluetooth: hci_intel: prevent reads beyond the end of skb->data Dan Carpenter
@ 2021-05-27 13:55 ` bluez.test.bot
2021-05-27 15:19 ` [PATCH] " Marcel Holtmann
1 sibling, 0 replies; 4+ messages in thread
From: bluez.test.bot @ 2021-05-27 13:55 UTC (permalink / raw)
To: linux-bluetooth, dan.carpenter
[-- Attachment #1: Type: text/plain, Size: 3953 bytes --]
This is automated email and please do not reply to this email!
Dear submitter,
Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=489559
---Test result---
Test Summary:
CheckPatch FAIL 0.75 seconds
GitLint FAIL 0.14 seconds
BuildKernel PASS 621.45 seconds
TestRunner: Setup PASS 399.93 seconds
TestRunner: l2cap-tester PASS 3.03 seconds
TestRunner: bnep-tester PASS 2.14 seconds
TestRunner: mgmt-tester PASS 28.10 seconds
TestRunner: rfcomm-tester PASS 2.30 seconds
TestRunner: sco-tester PASS 2.23 seconds
TestRunner: smp-tester PASS 2.36 seconds
TestRunner: userchan-tester PASS 2.13 seconds
Details
##############################
Test: CheckPatch - FAIL - 0.75 seconds
Run checkpatch.pl script with rule in .checkpatch.conf
Bluetooth: hci_intel: prevent reads beyond the end of skb->data
WARNING: Unknown commit id 'ca93cee5a56e', maybe rebased or not pulled?
#13:
Fixes: ca93cee5a56e ("Bluetooth: hci_uart: Add basic support for Intel Lightning Peak devices")
ERROR: Missing Signed-off-by: line(s)
total: 1 errors, 1 warnings, 22 lines checked
NOTE: For some of the reported defects, checkpatch may be able to
mechanically convert to the typical style using --fix or --fix-inplace.
"[PATCH] Bluetooth: hci_intel: prevent reads beyond the end of" has style problems, please review.
NOTE: If any of the errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.
##############################
Test: GitLint - FAIL - 0.14 seconds
Run gitlint with rule in .gitlint
Bluetooth: hci_intel: prevent reads beyond the end of skb->data
9: B1 Line exceeds max length (95>80): "Fixes: ca93cee5a56e ("Bluetooth: hci_uart: Add basic support for Intel Lightning Peak devices")"
18: B1 Line exceeds max length (101>80): "drivers/bluetooth/hci_intel.c:877 intel_recv_event() warn: assignment assumes 'skb->len' is '2' bytes"
19: B1 Line exceeds max length (99>80): "drivers/bluetooth/hci_intel.c:922 intel_recv_lpm() warn: assignment assumes 'skb->len' is '2' bytes"
20: B1 Line exceeds max length (99>80): "drivers/bluetooth/hci_intel.c:1028 intel_dequeue() warn: assignment assumes 'skb->len' is '3' bytes"
##############################
Test: BuildKernel - PASS - 621.45 seconds
Build Kernel with minimal configuration supports Bluetooth
##############################
Test: TestRunner: Setup - PASS - 399.93 seconds
Setup environment for running Test Runner
##############################
Test: TestRunner: l2cap-tester - PASS - 3.03 seconds
Run test-runner with l2cap-tester
Total: 40, Passed: 40 (100.0%), Failed: 0, Not Run: 0
##############################
Test: TestRunner: bnep-tester - PASS - 2.14 seconds
Run test-runner with bnep-tester
Total: 1, Passed: 1 (100.0%), Failed: 0, Not Run: 0
##############################
Test: TestRunner: mgmt-tester - PASS - 28.10 seconds
Run test-runner with mgmt-tester
Total: 433, Passed: 420 (97.0%), Failed: 0, Not Run: 13
##############################
Test: TestRunner: rfcomm-tester - PASS - 2.30 seconds
Run test-runner with rfcomm-tester
Total: 9, Passed: 9 (100.0%), Failed: 0, Not Run: 0
##############################
Test: TestRunner: sco-tester - PASS - 2.23 seconds
Run test-runner with sco-tester
Total: 8, Passed: 8 (100.0%), Failed: 0, Not Run: 0
##############################
Test: TestRunner: smp-tester - PASS - 2.36 seconds
Run test-runner with smp-tester
Total: 8, Passed: 8 (100.0%), Failed: 0, Not Run: 0
##############################
Test: TestRunner: userchan-tester - PASS - 2.13 seconds
Run test-runner with userchan-tester
Total: 3, Passed: 3 (100.0%), Failed: 0, Not Run: 0
---
Regards,
Linux Bluetooth
[-- Attachment #2: l2cap-tester.log --]
[-- Type: application/octet-stream, Size: 44350 bytes --]
[-- Attachment #3: bnep-tester.log --]
[-- Type: application/octet-stream, Size: 3556 bytes --]
[-- Attachment #4: mgmt-tester.log --]
[-- Type: application/octet-stream, Size: 568393 bytes --]
[-- Attachment #5: rfcomm-tester.log --]
[-- Type: application/octet-stream, Size: 11677 bytes --]
[-- Attachment #6: sco-tester.log --]
[-- Type: application/octet-stream, Size: 9912 bytes --]
[-- Attachment #7: smp-tester.log --]
[-- Type: application/octet-stream, Size: 11823 bytes --]
[-- Attachment #8: userchan-tester.log --]
[-- Type: application/octet-stream, Size: 5451 bytes --]
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] Bluetooth: hci_intel: prevent reads beyond the end of skb->data
2021-05-27 13:03 [PATCH] Bluetooth: hci_intel: prevent reads beyond the end of skb->data Dan Carpenter
2021-05-27 13:55 ` bluez.test.bot
@ 2021-05-27 15:19 ` Marcel Holtmann
2021-05-27 16:49 ` Dan Carpenter
1 sibling, 1 reply; 4+ messages in thread
From: Marcel Holtmann @ 2021-05-27 15:19 UTC (permalink / raw)
To: Dan Carpenter
Cc: Loic Poulain, Luiz Augusto von Dentz, Johan Hedberg,
linux-bluetooth, kernel-janitors
Hi Dan,
> There doesn't appear to be any checks to ensure that skb->data is large
> enough in these functions. For most of these, if we specify a header
> length, then h4_recv_buf() will ensure that all packets are at least the
> minimum length. The intel_recv_lpm() function needs an additional
> check for LPM_OP_TX_NOTIFY packets.
>
> Fixes: ca93cee5a56e ("Bluetooth: hci_uart: Add basic support for Intel Lightning Peak devices")
>
> No signed-off-by because I can't test this and just wanted to collect
> feedback. This is part of a static checker warning because someone
> reported the hci_event.c read overflows to security@kernel.org. This
> stuff is quite complicated for static checkers of course and I don't
> understand all the rules yet. Right now I have about 2000 warnings
> that look like this:
>
> drivers/bluetooth/hci_intel.c:877 intel_recv_event() warn: assignment assumes 'skb->len' is '2' bytes
> drivers/bluetooth/hci_intel.c:922 intel_recv_lpm() warn: assignment assumes 'skb->len' is '2' bytes
> drivers/bluetooth/hci_intel.c:1028 intel_dequeue() warn: assignment assumes 'skb->len' is '3' bytes
I think it will be hard to find people with this hardware. LnP devices are rare, but maybe someone will speak up here.
>
> I think there should be a different additional static checker warning
> for h4_recv_pkt structs like in this patch if you fail to specify a
> .hlen value?
>
> regards,
> dan carpenter
> ---
> drivers/bluetooth/hci_intel.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/bluetooth/hci_intel.c b/drivers/bluetooth/hci_intel.c
> index 7249b91d9b91..3e4bccacad9b 100644
> --- a/drivers/bluetooth/hci_intel.c
> +++ b/drivers/bluetooth/hci_intel.c
> @@ -925,7 +925,7 @@ static int intel_recv_lpm(struct hci_dev *hdev, struct sk_buff *skb)
>
> switch (lpm->opcode) {
> case LPM_OP_TX_NOTIFY:
> - if (lpm->dlen < 1) {
> + if (lpm->dlen < 1 || skb->len < struct_size(lpm, data, 1)) {
> bt_dev_err(hu->hdev, "Invalid LPM notification packet");
> break;
> }
This change looks fine to me and I would accept a patch for it.
> @@ -959,10 +959,10 @@ static int intel_recv_lpm(struct hci_dev *hdev, struct sk_buff *skb)
> .maxlen = HCI_LPM_MAX_SIZE
>
> static const struct h4_recv_pkt intel_recv_pkts[] = {
> - { H4_RECV_ACL, .recv = hci_recv_frame },
> - { H4_RECV_SCO, .recv = hci_recv_frame },
> - { H4_RECV_EVENT, .recv = intel_recv_event },
> - { INTEL_RECV_LPM, .recv = intel_recv_lpm },
> + { H4_RECV_ACL, .recv = hci_recv_frame, .hlen = sizeof(struct bt_skb_cb) },
> + { H4_RECV_SCO, .recv = hci_recv_frame, .hlen = sizeof(struct bt_skb_cb) },
> + { H4_RECV_EVENT, .recv = intel_recv_event, .hlen = sizeof(struct hci_event_hdr) },
> + { INTEL_RECV_LPM, .recv = intel_recv_lpm, .hlen = sizeof(struct hci_lpm_pkt) },
This part I do not understand, all the H4_RECV_* and even INTEL_RECV_* provide the hlen. So I have no idea what your change is doing here. And the two for H4_RECV_{ACL,SCO} are actually wrong. In case you wonder this is how they are defined:
#define H4_RECV_ACL \
.type = HCI_ACLDATA_PKT, \
.hlen = HCI_ACL_HDR_SIZE, \
.loff = 2, \
.lsize = 2, \
.maxlen = HCI_MAX_FRAME_SIZE \
#define H4_RECV_SCO \
.type = HCI_SCODATA_PKT, \
.hlen = HCI_SCO_HDR_SIZE, \
.loff = 2, \
.lsize = 1, \
.maxlen = HCI_MAX_SCO_SIZE
#define H4_RECV_EVENT \
.type = HCI_EVENT_PKT, \
.hlen = HCI_EVENT_HDR_SIZE, \
.loff = 1, \
.lsize = 1, \
.maxlen = HCI_MAX_EVENT_SIZE
Regards
Marcel
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] Bluetooth: hci_intel: prevent reads beyond the end of skb->data
2021-05-27 15:19 ` [PATCH] " Marcel Holtmann
@ 2021-05-27 16:49 ` Dan Carpenter
0 siblings, 0 replies; 4+ messages in thread
From: Dan Carpenter @ 2021-05-27 16:49 UTC (permalink / raw)
To: Marcel Holtmann
Cc: Loic Poulain, Luiz Augusto von Dentz, Johan Hedberg,
linux-bluetooth, kernel-janitors
On Thu, May 27, 2021 at 05:19:04PM +0200, Marcel Holtmann wrote:
> Hi Dan,
>
> > There doesn't appear to be any checks to ensure that skb->data is large
> > enough in these functions. For most of these, if we specify a header
> > length, then h4_recv_buf() will ensure that all packets are at least the
> > minimum length. The intel_recv_lpm() function needs an additional
> > check for LPM_OP_TX_NOTIFY packets.
> >
> > Fixes: ca93cee5a56e ("Bluetooth: hci_uart: Add basic support for Intel Lightning Peak devices")
> >
> > No signed-off-by because I can't test this and just wanted to collect
> > feedback. This is part of a static checker warning because someone
> > reported the hci_event.c read overflows to security@kernel.org. This
> > stuff is quite complicated for static checkers of course and I don't
> > understand all the rules yet. Right now I have about 2000 warnings
> > that look like this:
> >
> > drivers/bluetooth/hci_intel.c:877 intel_recv_event() warn: assignment assumes 'skb->len' is '2' bytes
> > drivers/bluetooth/hci_intel.c:922 intel_recv_lpm() warn: assignment assumes 'skb->len' is '2' bytes
> > drivers/bluetooth/hci_intel.c:1028 intel_dequeue() warn: assignment assumes 'skb->len' is '3' bytes
>
> I think it will be hard to find people with this hardware. LnP devices are rare, but maybe someone will speak up here.
>
It's easier to fix all the bugs than it is to try figure out if anyone
has the hardware. Plus if no one has the hardware then I will get the
credit for fixing a security bug with none of the risk of breaking
someone's system. ;)
[ snip ]
> > + { H4_RECV_ACL, .recv = hci_recv_frame, .hlen = sizeof(struct bt_skb_cb) },
> > + { H4_RECV_SCO, .recv = hci_recv_frame, .hlen = sizeof(struct bt_skb_cb) },
> > + { H4_RECV_EVENT, .recv = intel_recv_event, .hlen = sizeof(struct hci_event_hdr) },
> > + { INTEL_RECV_LPM, .recv = intel_recv_lpm, .hlen = sizeof(struct hci_lpm_pkt) },
>
> This part I do not understand, all the H4_RECV_* and even INTEL_RECV_* provide the hlen. So I have no idea what your change is doing here. And the two for H4_RECV_{ACL,SCO} are actually wrong. In case you wonder this is how they are defined:
>
> #define H4_RECV_ACL \
> .type = HCI_ACLDATA_PKT, \
> .hlen = HCI_ACL_HDR_SIZE, \
> .loff = 2, \
> .lsize = 2, \
> .maxlen = HCI_MAX_FRAME_SIZE \
>
> #define H4_RECV_SCO \
> .type = HCI_SCODATA_PKT, \
> .hlen = HCI_SCO_HDR_SIZE, \
> .loff = 2, \
> .lsize = 1, \
> .maxlen = HCI_MAX_SCO_SIZE
>
> #define H4_RECV_EVENT \
> .type = HCI_EVENT_PKT, \
> .hlen = HCI_EVENT_HDR_SIZE, \
> .loff = 1, \
> .lsize = 1, \
> .maxlen = HCI_MAX_EVENT_SIZE
Oh... Crap... I've been banging my head into the wall trying to figure
out why I couldn't make Smatch generate a warning for this. But now
when I remove the macro it does.
drivers/bluetooth/hci_intel.c:961 (null)() struct member not set 'intel_recv_pkts[0]->hlen'
It's embarrassing how long I have spend trying to figure out why it
said it was already initialized to non-zero...
regards,
dan carpenter
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-05-27 16:51 UTC | newest]
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2021-05-27 13:03 [PATCH] Bluetooth: hci_intel: prevent reads beyond the end of skb->data Dan Carpenter
2021-05-27 13:55 ` bluez.test.bot
2021-05-27 15:19 ` [PATCH] " Marcel Holtmann
2021-05-27 16:49 ` Dan Carpenter
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