| Message ID | 20230430180535.168270-1-lrh2000@pku.edu.cn (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] Bluetooth: Fix potential double free caused by hci_conn_unlink | expand |
| Context | Check | Description |
|---|---|---|
| tedd_an/pre-ci_am | success | Success |
| tedd_an/CheckPatch | success | CheckPatch PASS |
| tedd_an/GitLint | fail | 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 15: B3 Line contains hard tab characters (\t): " void hci_conn_del(struct hci_conn *conn)" 17: B1 Line exceeds max length (84>80): " https://lore.kernel.org/linux-bluetooth/20230430171847.156825-1-lrh2000@pku.edu.cn/" 17: B3 Line contains hard tab characters (\t): " https://lore.kernel.org/linux-bluetooth/20230430171847.156825-1-lrh2000@pku.edu.cn/" |
| tedd_an/SubjectPrefix | success | Gitlint PASS |
| tedd_an/BuildKernel | success | BuildKernel PASS |
| tedd_an/CheckAllWarning | success | CheckAllWarning PASS |
| tedd_an/CheckSparse | success | CheckSparse PASS |
| tedd_an/CheckSmatch | success | CheckSparse PASS |
| tedd_an/BuildKernel32 | success | BuildKernel32 PASS |
| tedd_an/TestRunnerSetup | success | TestRunnerSetup PASS |
| tedd_an/TestRunner_l2cap-tester | success | TestRunner PASS |
| tedd_an/TestRunner_iso-tester | success | TestRunner PASS |
| tedd_an/TestRunner_bnep-tester | success | TestRunner PASS |
| tedd_an/TestRunner_mgmt-tester | success | TestRunner PASS |
| tedd_an/TestRunner_rfcomm-tester | success | TestRunner PASS |
| tedd_an/TestRunner_sco-tester | success | TestRunner PASS |
| tedd_an/TestRunner_ioctl-tester | success | TestRunner PASS |
| tedd_an/TestRunner_mesh-tester | success | TestRunner PASS |
| tedd_an/TestRunner_smp-tester | success | TestRunner PASS |
| tedd_an/TestRunner_userchan-tester | success | TestRunner PASS |
| tedd_an/IncrementalBuild | success | Incremental Build PASS |
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=744077 ---Test result--- Test Summary: CheckPatch PASS 0.70 seconds GitLint FAIL 0.56 seconds SubjectPrefix PASS 0.13 seconds BuildKernel PASS 31.08 seconds CheckAllWarning PASS 34.53 seconds CheckSparse PASS 39.20 seconds CheckSmatch PASS 109.45 seconds BuildKernel32 PASS 30.18 seconds TestRunnerSetup PASS 441.36 seconds TestRunner_l2cap-tester PASS 16.54 seconds TestRunner_iso-tester PASS 20.36 seconds TestRunner_bnep-tester PASS 5.30 seconds TestRunner_mgmt-tester PASS 111.39 seconds TestRunner_rfcomm-tester PASS 8.46 seconds TestRunner_sco-tester PASS 7.88 seconds TestRunner_ioctl-tester PASS 9.17 seconds TestRunner_mesh-tester PASS 6.77 seconds TestRunner_smp-tester PASS 7.77 seconds TestRunner_userchan-tester PASS 5.56 seconds IncrementalBuild PASS 28.59 seconds Details ############################## Test: GitLint - FAIL Desc: Run gitlint Output: [v2] Bluetooth: Fix potential double free caused by hci_conn_unlink 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 15: B3 Line contains hard tab characters (\t): " void hci_conn_del(struct hci_conn *conn)" 17: B1 Line exceeds max length (84>80): " https://lore.kernel.org/linux-bluetooth/20230430171847.156825-1-lrh2000@pku.edu.cn/" 17: B3 Line contains hard tab characters (\t): " https://lore.kernel.org/linux-bluetooth/20230430171847.156825-1-lrh2000@pku.edu.cn/" --- Regards, Linux Bluetooth
On Mon, May 01, 2023 at 02:05:35AM +0800, Ruihan Li wrote: > The hci_conn_unlink function is being called by hci_conn_del, which means > it should not call hci_conn_del with the input parameter conn again. If it > does, conn may have already been released when hci_conn_unlink returns, > leading to potential UAF and double-free issues. > > This patch resolves the problem by modifying hci_conn_unlink to release > only conn's child links when necessary, but never release conn itself. Syzbot also found this bug several days ago (but it does not email linux-bluetooth until today). Reported-by: syzbot+690b90b14f14f43f4688@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=690b90b14f14f43f4688 > Fixes: 06149746e720 ("Bluetooth: hci_conn: Add support for linking multiple hcon") > Signed-off-by: Ruihan Li <lrh2000@pku.edu.cn> > --- > Changes since v1: > * CI complains that there are some merge conflicts. This is because > void hci_conn_del(struct hci_conn *conn) > this completely unrelated line makes the patch dependent on another fix: > https://lore.kernel.org/linux-bluetooth/20230430171847.156825-1-lrh2000@pku.edu.cn/ > But actually, deleting that line makes the two patches independent of > each other, and everything still works. > > net/bluetooth/hci_conn.c | 21 ++++++++++++--------- > 1 file changed, 12 insertions(+), 9 deletions(-) > > diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c > index 85c34c837..5f388202f 100644 > --- a/net/bluetooth/hci_conn.c > +++ b/net/bluetooth/hci_conn.c > @@ -1083,8 +1083,18 @@ static void hci_conn_unlink(struct hci_conn *conn) > if (!conn->parent) { > struct hci_link *link, *t; > > - list_for_each_entry_safe(link, t, &conn->link_list, list) > - hci_conn_unlink(link->conn); > + list_for_each_entry_safe(link, t, &conn->link_list, list) { > + struct hci_conn *child = link->conn; > + > + hci_conn_unlink(child); > + > + /* Due to race, SCO connection might be not established > + * yet at this point. Delete it now, otherwise it is > + * possible for it to be stuck and can't be deleted. > + */ > + if (child->handle == HCI_CONN_HANDLE_UNSET) > + hci_conn_del(child); > + } > > return; > } > @@ -1100,12 +1110,5 @@ static void hci_conn_unlink(struct hci_conn *conn) > > kfree(conn->link); > conn->link = NULL; > - > - /* Due to race, SCO connection might be not established > - * yet at this point. Delete it now, otherwise it is > - * possible for it to be stuck and can't be deleted. > - */ > - if (conn->handle == HCI_CONN_HANDLE_UNSET) > - hci_conn_del(conn); > } > > -- > 2.40.0 Thanks, Ruihan Li
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c index 85c34c837..5f388202f 100644 --- a/net/bluetooth/hci_conn.c +++ b/net/bluetooth/hci_conn.c @@ -1083,8 +1083,18 @@ static void hci_conn_unlink(struct hci_conn *conn) if (!conn->parent) { struct hci_link *link, *t; - list_for_each_entry_safe(link, t, &conn->link_list, list) - hci_conn_unlink(link->conn); + list_for_each_entry_safe(link, t, &conn->link_list, list) { + struct hci_conn *child = link->conn; + + hci_conn_unlink(child); + + /* Due to race, SCO connection might be not established + * yet at this point. Delete it now, otherwise it is + * possible for it to be stuck and can't be deleted. + */ + if (child->handle == HCI_CONN_HANDLE_UNSET) + hci_conn_del(child); + } return; } @@ -1100,12 +1110,5 @@ static void hci_conn_unlink(struct hci_conn *conn) kfree(conn->link); conn->link = NULL; - - /* Due to race, SCO connection might be not established - * yet at this point. Delete it now, otherwise it is - * possible for it to be stuck and can't be deleted. - */ - if (conn->handle == HCI_CONN_HANDLE_UNSET) - hci_conn_del(conn); }
The hci_conn_unlink function is being called by hci_conn_del, which means it should not call hci_conn_del with the input parameter conn again. If it does, conn may have already been released when hci_conn_unlink returns, leading to potential UAF and double-free issues. This patch resolves the problem by modifying hci_conn_unlink to release only conn's child links when necessary, but never release conn itself. Fixes: 06149746e720 ("Bluetooth: hci_conn: Add support for linking multiple hcon") Signed-off-by: Ruihan Li <lrh2000@pku.edu.cn> --- Changes since v1: * CI complains that there are some merge conflicts. This is because void hci_conn_del(struct hci_conn *conn) this completely unrelated line makes the patch dependent on another fix: https://lore.kernel.org/linux-bluetooth/20230430171847.156825-1-lrh2000@pku.edu.cn/ But actually, deleting that line makes the two patches independent of each other, and everything still works. net/bluetooth/hci_conn.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-)