kernel/linux.git/net/bluetooth/hci_sync.c, branch linux-7.1.y

Bluetooth: hci_sync: reject oversized Broadcast Announcement prepend

2026-06-03T15:21:48+00:00

Existing advertising instances can already hold the maximum extended advertising payload. When hci_adv_bcast_annoucement() prepends the Broadcast Announcement service data to that payload, the combined data may no longer fit in the temporary buffer used to rebuild the advertising data. Reject that case before copying the existing payload and report the failure through the device log. This keeps the existing advertising data intact and avoids overrunning the temporary buffer. Fixes: 5725bc608252 ("Bluetooth: hci_sync: Fix broadcast/PA when using an existing instance") Cc: stable@kernel.org Reported-by: Yuan Tan Reported-by: Zhengchuan Liang Reported-by: Xin Liu Assisted-by: Codex:GPT-5.4 Signed-off-by: Yuqi Xu Signed-off-by: Ren Wei Signed-off-by: Luiz Augusto von Dentz

Bluetooth: hci_sync: Reset device counters in hci_dev_close_sync()

2026-05-28T12:52:21+00:00

Before resetting or closing the device, protocol counters should also be zeroed. Fixes: d0b137062b2d ("Bluetooth: hci_sync: Rework init stages") Signed-off-by: Heitor Alves de Siqueira Signed-off-by: Luiz Augusto von Dentz

Bluetooth: hci_sync: Set HCI_CMD_DRAIN_WORKQUEUE during device close

2026-05-28T12:52:21+00:00

Since hci_dev_close_sync() can now be called during the reset path, we should also set HCI_CMD_DRAIN_WORKQUEUE. This avoids queuing timeouts while the hdev workqueue is being drained. Fixes: 877afadad2dc ("Bluetooth: When HCI work queue is drained, only queue chained work") Signed-off-by: Heitor Alves de Siqueira Signed-off-by: Luiz Augusto von Dentz

Bluetooth: hci_sync: fix UAF in hci_le_create_cis_sync

2026-05-27T20:44:02+00:00

hci_le_create_cis_sync() dereferences conn->conn_timeout after releasing both rcu_read_lock() and hci_dev_lock(hdev). The conn pointer was obtained from an RCU-protected iteration over hdev->conn_hash.list and is not valid once these locks are dropped. A concurrent disconnect can free the hci_conn between the unlock and the dereference, causing a use-after-free read. The cancellation mechanism in hci_conn_del() cannot prevent this because hci_le_create_cis_pending() queues hci_create_cis_sync with data=NULL: hci_cmd_sync_queue(hdev, hci_create_cis_sync, NULL, NULL); While hci_conn_del() dequeues with data=conn: hci_cmd_sync_dequeue(hdev, NULL, conn, NULL); Since NULL != conn, the lookup in _hci_cmd_sync_lookup_entry() never matches, and the pending work item is not cancelled. Fix this by saving conn->conn_timeout into a local variable while the locks are still held, so the stale conn pointer is never dereferenced after unlock. This is the same class of bug as the one fixed by commit 035c25007c9e ("Bluetooth: hci_sync: Fix UAF on le_read_features_complete") which addressed the identical pattern in a different function. This vulnerability was identified using 0sec.ai, an open-source automated security auditing platform (https://github.com/0sec-labs). Fixes: c09b80be6ffc ("Bluetooth: hci_conn: Fix not waiting for HCI_EVT_LE_CIS_ESTABLISHED") Cc: stable@vger.kernel.org Reported-by: Doruk Tan Ozturk Signed-off-by: Doruk Tan Ozturk Signed-off-by: Luiz Augusto von Dentz

Bluetooth: hci_sync: Fix not setting mask for HCI_EVT_LE_ALL_REMOTE_FEATURES_COMPLETE

2026-05-20T20:35:47+00:00

This fixes not setting the bit for HCI_EVT_LE_ALL_REMOTE_FEATURES_COMPLETE when extended features bit is set otherwise the controller may not generate HCI_EVT_LE_ALL_REMOTE_FEATURES_COMPLETE causing hci_le_read_all_remote_features_sync to timeout waiting for it. Also remove dead code. Fixes: a106e50be74b ("Bluetooth: HCI: Add support for LL Extended Feature Set") Signed-off-by: Luiz Augusto von Dentz

Bluetooth: hci_sync: make hci_cmd_sync_run_once return -EEXIST if exists

2026-04-13T13:18:16+00:00

hci_cmd_sync_run_once() needs to indicate whether a queue item was added, so caller can know if callbacks are called, so it can avoid leaking resources. Change the function to return -EEXIST if queue item already exists. Modify all callsites vs. the changes. The only callsite is hci_abort_conn(). Signed-off-by: Pauli Virtanen Signed-off-by: Luiz Augusto von Dentz

Bluetooth: hci_sync: fix stack buffer overflow in hci_le_big_create_sync

2026-04-01T20:48:28+00:00

hci_le_big_create_sync() uses DEFINE_FLEX to allocate a struct hci_cp_le_big_create_sync on the stack with room for 0x11 (17) BIS entries. However, conn->num_bis can hold up to HCI_MAX_ISO_BIS (31) entries — validated against ISO_MAX_NUM_BIS (0x1f) in the caller hci_conn_big_create_sync(). When conn->num_bis is between 18 and 31, the memcpy that copies conn->bis into cp->bis writes up to 14 bytes past the stack buffer, corrupting adjacent stack memory. This is trivially reproducible: binding an ISO socket with bc_num_bis = ISO_MAX_NUM_BIS (31) and calling listen() will eventually trigger hci_le_big_create_sync() from the HCI command sync worker, causing a KASAN-detectable stack-out-of-bounds write: BUG: KASAN: stack-out-of-bounds in hci_le_big_create_sync+0x256/0x3b0 Write of size 31 at addr ffffc90000487b48 by task kworker/u9:0/71 Fix this by changing the DEFINE_FLEX count from the incorrect 0x11 to HCI_MAX_ISO_BIS, which matches the maximum number of BIS entries that conn->bis can actually carry. Fixes: 42ecf1947135 ("Bluetooth: ISO: Do not emit LE BIG Create Sync if previous is pending") Cc: stable@vger.kernel.org Signed-off-by: hkbinbin Reviewed-by: Paul Menzel Signed-off-by: Luiz Augusto von Dentz

Bluetooth: hci_sync: Fix UAF in le_read_features_complete

2026-04-01T20:45:24+00:00

This fixes the following backtrace caused by hci_conn being freed before le_read_features_complete but after hci_le_read_remote_features_sync so hci_conn_del -> hci_cmd_sync_dequeue is not able to prevent it: ================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline] BUG: KASAN: slab-use-after-free in atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1383 [inline] BUG: KASAN: slab-use-after-free in hci_conn_drop include/net/bluetooth/hci_core.h:1688 [inline] BUG: KASAN: slab-use-after-free in le_read_features_complete+0x5b/0x340 net/bluetooth/hci_sync.c:7344 Write of size 4 at addr ffff8880796b0010 by task kworker/u9:0/52 CPU: 0 UID: 0 PID: 52 Comm: kworker/u9:0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: hci0 hci_cmd_sync_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:194 [inline] kasan_check_range+0x100/0x1b0 mm/kasan/generic.c:200 instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1383 [inline] hci_conn_drop include/net/bluetooth/hci_core.h:1688 [inline] le_read_features_complete+0x5b/0x340 net/bluetooth/hci_sync.c:7344 hci_cmd_sync_work+0x1ff/0x430 net/bluetooth/hci_sync.c:334 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Allocated by task 5932: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] __hci_conn_add+0xf8/0x1c70 net/bluetooth/hci_conn.c:963 hci_conn_add_unset+0x76/0x100 net/bluetooth/hci_conn.c:1084 le_conn_complete_evt+0x639/0x1f20 net/bluetooth/hci_event.c:5714 hci_le_enh_conn_complete_evt+0x23d/0x380 net/bluetooth/hci_event.c:5861 hci_le_meta_evt+0x357/0x5e0 net/bluetooth/hci_event.c:7408 hci_event_func net/bluetooth/hci_event.c:7716 [inline] hci_event_packet+0x685/0x11c0 net/bluetooth/hci_event.c:7773 hci_rx_work+0x2c9/0xeb0 net/bluetooth/hci_core.c:4076 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Freed by task 5932: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 __kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6663 [inline] kfree+0x2f8/0x6e0 mm/slub.c:6871 device_release+0xa4/0x240 drivers/base/core.c:2565 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1e7/0x590 lib/kobject.c:737 put_device drivers/base/core.c:3797 [inline] device_unregister+0x2f/0xc0 drivers/base/core.c:3920 hci_conn_del_sysfs+0xb4/0x180 net/bluetooth/hci_sysfs.c:79 hci_conn_cleanup net/bluetooth/hci_conn.c:173 [inline] hci_conn_del+0x657/0x1180 net/bluetooth/hci_conn.c:1234 hci_disconn_complete_evt+0x410/0xa00 net/bluetooth/hci_event.c:3451 hci_event_func net/bluetooth/hci_event.c:7719 [inline] hci_event_packet+0xa10/0x11c0 net/bluetooth/hci_event.c:7773 hci_rx_work+0x2c9/0xeb0 net/bluetooth/hci_core.c:4076 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 The buggy address belongs to the object at ffff8880796b0000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 16 bytes inside of freed 8192-byte region [ffff8880796b0000, ffff8880796b2000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x796b0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813ff27280 0000000000000000 0000000000000001 raw: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813ff27280 0000000000000000 0000000000000001 head: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001e5ac01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5657, tgid 5657 (dhcpcd-run-hook), ts 79819636908, free_ts 79814310558 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1845 prep_new_page mm/page_alloc.c:1853 [inline] get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3879 __alloc_frozen_pages_noprof+0x25f/0x2440 mm/page_alloc.c:5183 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab mm/slub.c:3248 [inline] new_slab+0x2c3/0x430 mm/slub.c:3302 ___slab_alloc+0xe18/0x1c90 mm/slub.c:4651 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4774 __slab_alloc_node mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:5246 [inline] __kmalloc_cache_noprof+0x477/0x800 mm/slub.c:5766 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] tomoyo_print_bprm security/tomoyo/audit.c:26 [inline] tomoyo_init_log+0xc8a/0x2140 security/tomoyo/audit.c:264 tomoyo_supervisor+0x302/0x13b0 security/tomoyo/common.c:2198 tomoyo_audit_env_log security/tomoyo/environ.c:36 [inline] tomoyo_env_perm+0x191/0x200 security/tomoyo/environ.c:63 tomoyo_environ security/tomoyo/domain.c:672 [inline] tomoyo_find_next_domain+0xec1/0x20b0 security/tomoyo/domain.c:888 tomoyo_bprm_check_security security/tomoyo/tomoyo.c:102 [inline] tomoyo_bprm_check_security+0x12d/0x1d0 security/tomoyo/tomoyo.c:92 security_bprm_check+0x1b9/0x1e0 security/security.c:794 search_binary_handler fs/exec.c:1659 [inline] exec_binprm fs/exec.c:1701 [inline] bprm_execve fs/exec.c:1753 [inline] bprm_execve+0x81e/0x1620 fs/exec.c:1729 do_execveat_common.isra.0+0x4a5/0x610 fs/exec.c:1859 page last free pid 5657 tgid 5657 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2901 discard_slab mm/slub.c:3346 [inline] __put_partials+0x130/0x170 mm/slub.c:3886 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4c/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:352 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4948 [inline] slab_alloc_node mm/slub.c:5258 [inline] __kmalloc_cache_noprof+0x274/0x800 mm/slub.c:5766 kmalloc_noprof include/linux/slab.h:957 [inline] tomoyo_print_header security/tomoyo/audit.c:156 [inline] tomoyo_init_log+0x197/0x2140 security/tomoyo/audit.c:255 tomoyo_supervisor+0x302/0x13b0 security/tomoyo/common.c:2198 tomoyo_audit_env_log security/tomoyo/environ.c:36 [inline] tomoyo_env_perm+0x191/0x200 security/tomoyo/environ.c:63 tomoyo_environ security/tomoyo/domain.c:672 [inline] tomoyo_find_next_domain+0xec1/0x20b0 security/tomoyo/domain.c:888 tomoyo_bprm_check_security security/tomoyo/tomoyo.c:102 [inline] tomoyo_bprm_check_security+0x12d/0x1d0 security/tomoyo/tomoyo.c:92 security_bprm_check+0x1b9/0x1e0 security/security.c:794 search_binary_handler fs/exec.c:1659 [inline] exec_binprm fs/exec.c:1701 [inline] bprm_execve fs/exec.c:1753 [inline] bprm_execve+0x81e/0x1620 fs/exec.c:1729 do_execveat_common.isra.0+0x4a5/0x610 fs/exec.c:1859 do_execve fs/exec.c:1933 [inline] __do_sys_execve fs/exec.c:2009 [inline] __se_sys_execve fs/exec.c:2004 [inline] __x64_sys_execve+0x8e/0xb0 fs/exec.c:2004 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 Memory state around the buggy address: ffff8880796aff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880796aff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880796b0000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880796b0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880796b0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Fixes: a106e50be74b ("Bluetooth: HCI: Add support for LL Extended Feature Set") Reported-by: syzbot+87badbb9094e008e0685@syzkaller.appspotmail.com Tested-by: syzbot+87badbb9094e008e0685@syzkaller.appspotmail.com Closes: https://syzbot.org/bug?extid=87badbb9094e008e0685 Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Pauli Virtanen

Bluetooth: hci_sync: fix leaks when hci_cmd_sync_queue_once fails

2026-04-01T20:45:00+00:00

When hci_cmd_sync_queue_once() returns with error, the destroy callback will not be called. Fix leaking references / memory on these failures. Signed-off-by: Pauli Virtanen Signed-off-by: Luiz Augusto von Dentz

Bluetooth: hci_sync: hci_cmd_sync_queue_once() return -EEXIST if exists

2026-04-01T20:44:38+00:00

hci_cmd_sync_queue_once() needs to indicate whether a queue item was added, so caller can know if callbacks are called, so it can avoid leaking resources. Change the function to return -EEXIST if queue item already exists. Modify all callsites to handle that. Signed-off-by: Pauli Virtanen Signed-off-by: Luiz Augusto von Dentz