2021-01-26 21:49:05

by Sonny Sasaka

[permalink] [raw]
Subject: [PATCH BlueZ] input/hog: Fix crashes of UAF of hog->attr

hog->attr does not own pointer, so it may be invalid when hog object
gets re-attached at bt_hog_attach(). To solve this, this patch
intentionally clears hog->attr at bt_hog_detach() to mark it as invalid
so that it can be repopulated with the valid pointer at bt_hog_attach().
The same applies to all sub-instances.

Sample stack trace:
* thread #1, stop reason = signal SIGSEGV
* frame #0: 0x05ad49f2 bluetoothd`<name omitted> at gatt-db.c:1428
frame #1: 0x05a91922 bluetoothd`bt_hog_attach at hog-lib.c:1694
frame #2: 0x05a9160e bluetoothd`hog_accept at hog.c:212
frame #3: 0x05ab4784 bluetoothd`service_accept at service.c:203
frame #4: 0x05aba1e6 bluetoothd`device_attach_att at device.c:4542
frame #5: 0x05a9c4a2 bluetoothd`connect_cb at gatt-database.c:656
frame #6: 0x05a98e8c bluetoothd`server_cb at btio.c:264
frame #7: 0xec8e6a1a libglib-2.0.so.0`g_main_context_dispatch at gmain.c:3325
frame #8: 0xec8e6c58 libglib-2.0.so.0`g_main_context_iterate at gmain.c:4119
frame #9: 0xec8e6e52 libglib-2.0.so.0`g_main_loop_run at gmain.c:4317
frame #10: 0x05ad582e bluetoothd`mainloop_run at mainloop-glib.c:79
frame #11: 0x05ad5a64 bluetoothd`mainloop_run_with_signal at mainloop-notify.c:201
frame #12: 0x05ac35ac bluetoothd`main at main.c:1103
frame #13: 0xec6ed0a2 libc.so.6`__libc_start_main at libc-start.c:308

---
profiles/input/hog-lib.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)

diff --git a/profiles/input/hog-lib.c b/profiles/input/hog-lib.c
index 1f132aa4c..7d1ea53bd 100644
--- a/profiles/input/hog-lib.c
+++ b/profiles/input/hog-lib.c
@@ -1651,12 +1651,19 @@ static void primary_cb(uint8_t status, GSList *services, void *user_data)
bool bt_hog_attach(struct bt_hog *hog, void *gatt)
{
GSList *l;
+ bt_uuid_t uuid;

if (hog->attrib)
return false;

hog->attrib = g_attrib_ref(gatt);

+ if (!hog->attr && hog->gatt_db) {
+ bt_uuid16_create(&uuid, HOG_UUID16);
+ gatt_db_foreach_service(hog->gatt_db, &uuid,
+ foreach_hog_service, hog);
+ }
+
if (!hog->attr && !hog->primary) {
discover_primary(hog, hog->attrib, NULL, primary_cb, hog);
return true;
@@ -1744,6 +1751,14 @@ void bt_hog_detach(struct bt_hog *hog)
bt_hog_detach(instance);
}

+ /* hog->attr doesn't own pointer, so it may be invalid when this hog
+ * object gets re-attached with bt_hog_attach(). So intentionally mark
+ * it as invalid and remove all instances so that the instances can be
+ * re-attached at bt_hog_attach().
+ */
+ hog->attr = NULL;
+ g_slist_free_full(hog->instances, hog_free);
+
for (l = hog->reports; l; l = l->next) {
struct report *r = l->data;

--
2.29.2


2021-01-27 19:43:53

by bluez.test.bot

[permalink] [raw]
Subject: RE: [BlueZ] input/hog: Fix crashes of UAF of hog->attr

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=422227

---Test result---

##############################
Test: CheckPatch - FAIL
Output:
input/hog: Fix crashes of UAF of hog->attr
WARNING:COMMIT_LOG_LONG_LINE: Possible unwrapped commit description (prefer a maximum 75 chars per line)
#21:
frame #7: 0xec8e6a1a libglib-2.0.so.0`g_main_context_dispatch at gmain.c:3325

- total: 0 errors, 1 warnings, 33 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] input/hog: Fix crashes of UAF of hog->attr" has style problems, please review.

NOTE: Ignored message types: COMMIT_MESSAGE COMPLEX_MACRO CONST_STRUCT FILE_PATH_CHANGES MISSING_SIGN_OFF PREFER_PACKED SPLIT_STRING SSCANF_TO_KSTRTO

NOTE: If any of the errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.


##############################
Test: CheckGitLint - FAIL
Output:
input/hog: Fix crashes of UAF of hog->attr
18: B1 Line exceeds max length (81>80): " frame #7: 0xec8e6a1a libglib-2.0.so.0`g_main_context_dispatch at gmain.c:3325"
22: B1 Line exceeds max length (86>80): " frame #11: 0x05ad5a64 bluetoothd`mainloop_run_with_signal at mainloop-notify.c:201"


##############################
Test: CheckBuild - PASS

##############################
Test: MakeCheck - FAIL
Output:
./test-driver: line 107: 14777 Segmentation fault (core dumped) "$@" > $log_file 2>&1
make[3]: *** [Makefile:9755: test-suite.log] Error 1
make[2]: *** [Makefile:9863: check-TESTS] Error 2
make[1]: *** [Makefile:10257: check-am] Error 2
make: *** [Makefile:10259: check] Error 2




---
Regards,
Linux Bluetooth