[BlueZ,v2] shared/bap: fix crash unregistering media endpoint while streaming

Commit Message

Pauli Virtanen Feb. 24, 2023, 6:09 p.m. UTC

Always free BAP stream in bt_bap_stream_release if it is not attached to
a client session, simplifying the cleanup.

Fixes the following ASAN crash is observed when media endpoint is
unregistered (stopping sound server) while streaming from remote BAP
client:

ERROR: AddressSanitizer: heap-use-after-free on address 0x60b0000474d8
READ of size 8 at 0x60b0000474d8 thread T0
    #0 0x7a27c6 in stream_set_state src/shared/bap.c:1227
    #1 0x7aff61 in remove_streams src/shared/bap.c:2483
    #2 0x71d2d0 in queue_foreach src/shared/queue.c:207
    #3 0x7b0152 in bt_bap_remove_pac src/shared/bap.c:2501
    #4 0x463cda in media_endpoint_destroy profiles/audio/media.c:179
    ...
0x60b0000474d8 is located 8 bytes inside of 112-byte region
freed by thread T0 here:
    #0 0x7f93b12b9388 in __interceptor_free.part.0 (/lib64/libasan.so.8+0xb9388)
    #1 0x7a0504 in bap_stream_free src/shared/bap.c:972
    #2 0x7a0800 in bap_stream_detach src/shared/bap.c:989
    #3 0x7a26d1 in bap_stream_state_changed src/shared/bap.c:1208
    #4 0x7a2ab4 in stream_set_state src/shared/bap.c:1252
    #5 0x7ab18a in stream_release src/shared/bap.c:1985
    #6 0x7c6919 in bt_bap_stream_release src/shared/bap.c:4572
    #7 0x7aff50 in remove_streams src/shared/bap.c:2482
    ...
previously allocated by thread T0 here:
    #0 0x7f93b12ba6af in __interceptor_malloc (/lib64/libasan.so.8+0xba6af)
    #1 0x71e9ae in util_malloc src/shared/util.c:43
    #2 0x79c2f5 in bap_stream_new src/shared/bap.c:766
    #3 0x7a4863 in ep_config src/shared/bap.c:1446
    #4 0x7a4f22 in ascs_config src/shared/bap.c:1481
    ...
---

Notes:
    v2: move cleanup inside bt_bap_stream_release
    
    Following the suggestion, maybe like this then?
    
    The rule then is that bt_bap_stream_free frees the stream if it does not
    belong to a client session.
    
    The dangling stream pointer should not be put into req.

 src/shared/bap.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

Comments

[e-mail] Feb. 24, 2023, 7:11 p.m. UTC | #1

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=724727

---Test result---

Test Summary:
CheckPatch                    FAIL      0.96 seconds
GitLint                       FAIL      0.63 seconds
BuildEll                      PASS      26.04 seconds
BluezMake                     PASS      738.47 seconds
MakeCheck                     PASS      11.00 seconds
MakeDistcheck                 PASS      146.15 seconds
CheckValgrind                 PASS      238.35 seconds
CheckSmatch                   PASS      319.64 seconds
bluezmakeextell               PASS      95.26 seconds
IncrementalBuild              PASS      597.16 seconds
ScanBuild                     PASS      935.23 seconds

Details
##############################
Test: CheckPatch - FAIL
Desc: Run checkpatch.pl script
Output:
[BlueZ,v2] shared/bap: fix crash unregistering media endpoint while streaming
WARNING:COMMIT_LOG_LONG_LINE: Possible unwrapped commit description (prefer a maximum 75 chars per line)
#68: 
    #0 0x7f93b12b9388 in __interceptor_free.part.0 (/lib64/libasan.so.8+0xb9388)

/github/workspace/src/src/13151651.patch total: 0 errors, 1 warnings, 36 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.

/github/workspace/src/src/13151651.patch has style problems, please review.

NOTE: Ignored message types: COMMIT_MESSAGE COMPLEX_MACRO CONST_STRUCT FILE_PATH_CHANGES MISSING_SIGN_OFF PREFER_PACKED SPDX_LICENSE_TAG 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: GitLint - FAIL
Desc: Run gitlint
Output:
[BlueZ,v2] shared/bap: fix crash unregistering media endpoint while streaming

WARNING: I3 - ignore-body-lines: gitlint will be switching from using Python regex 'match' (match beginning) to 'search' (match anywhere) semantics. Please review your ignore-body-lines.regex option accordingly. To remove this warning, set general.regex-style-search=True. More details: https://jorisroovers.github.io/gitlint/configuration/#regex-style-search
40: B2 Line has trailing whitespace: "    "
42: B2 Line has trailing whitespace: "    "
45: B2 Line has trailing whitespace: "    "


---
Regards,
Linux Bluetooth

[e-mail] Feb. 27, 2023, 9:40 p.m. UTC | #2

Hello:

This patch was applied to bluetooth/bluez.git (master)
by Luiz Augusto von Dentz <[e-mail]>:

On Fri, 24 Feb 2023 18:09:46 +0000 you wrote:
> Always free BAP stream in bt_bap_stream_release if it is not attached to
> a client session, simplifying the cleanup.
> 
> Fixes the following ASAN crash is observed when media endpoint is
> unregistered (stopping sound server) while streaming from remote BAP
> client:
> 
> [...]

Here is the summary with links:
  - [BlueZ,v2] shared/bap: fix crash unregistering media endpoint while streaming
    https://git.kernel.org/pub/scm/bluetooth/bluez.git/?id=fcdd38acf6b2

You are awesome, thank you!

Patch

diff --git a/src/shared/bap.c b/src/shared/bap.c
index f16ba1832..41b39f868 100644
--- a/src/shared/bap.c
+++ b/src/shared/bap.c
@@ -2479,10 +2479,8 @@  static void remove_streams(void *data, void *user_data)
 	struct bt_bap_stream *stream;
 
 	stream = queue_remove_if(bap->streams, match_stream_lpac, pac);
-	if (stream) {
+	if (stream)
 		bt_bap_stream_release(stream, NULL, NULL);
-		stream_set_state(stream, BT_BAP_STREAM_STATE_IDLE);
-	}
 }
 
 bool bt_bap_remove_pac(struct bt_bap_pac *pac)
@@ -4567,6 +4565,7 @@  unsigned int bt_bap_stream_release(struct bt_bap_stream *stream,
 	struct iovec iov;
 	struct bt_ascs_release rel;
 	struct bt_bap_req *req;
+	struct bt_bap *bap;
 
 	if (!stream)
 		return 0;
@@ -4583,9 +4582,17 @@  unsigned int bt_bap_stream_release(struct bt_bap_stream *stream,
 	iov.iov_base = &rel;
 	iov.iov_len = sizeof(rel);
 
+	bap = stream->bap;
+
+	/* If stream does not belong to a client session, clean it up now */
+	if (!bap_stream_valid(stream)) {
+		stream_set_state(stream, BT_BAP_STREAM_STATE_IDLE);
+		stream = NULL;
+	}
+
 	req = bap_req_new(stream, BT_ASCS_RELEASE, &iov, 1, func, user_data);
 
-	if (!bap_queue_req(stream->bap, req)) {
+	if (!bap_queue_req(bap, req)) {
 		bap_req_free(req);
 		return 0;
 	}