From 1d6123102e9fbedc8d25bf4731da6d513173e49e Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Tue, 17 Jun 2025 09:58:13 -0700 Subject: Bluetooth: hci_core: Fix use-after-free in vhci_flush() syzbot reported use-after-free in vhci_flush() without repro. [0] From the splat, a thread close()d a vhci file descriptor while its device was being used by iotcl() on another thread. Once the last fd refcnt is released, vhci_release() calls hci_unregister_dev(), hci_free_dev(), and kfree() for struct vhci_data, which is set to hci_dev->dev->driver_data. The problem is that there is no synchronisation after unlinking hdev from hci_dev_list in hci_unregister_dev(). There might be another thread still accessing the hdev which was fetched before the unlink operation. We can use SRCU for such synchronisation. Let's run hci_dev_reset() under SRCU and wait for its completion in hci_unregister_dev(). Another option would be to restore hci_dev->destruct(), which was removed in commit 587ae086f6e4 ("Bluetooth: Remove unused hci-destruct cb"). However, this would not be a good solution, as we should not run hci_unregister_dev() while there are in-flight ioctl() requests, which could lead to another data-race KCSAN splat. Note that other drivers seem to have the same problem, for exmaple, virtbt_remove(). [0]: BUG: KASAN: slab-use-after-free in skb_queue_empty_lockless include/linux/skbuff.h:1891 [inline] BUG: KASAN: slab-use-after-free in skb_queue_purge_reason+0x99/0x360 net/core/skbuff.c:3937 Read of size 8 at addr ffff88807cb8d858 by task syz.1.219/6718 CPU: 1 UID: 0 PID: 6718 Comm: syz.1.219 Not tainted 6.16.0-rc1-syzkaller-00196-g08207f42d3ff #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xd2/0x2b0 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 skb_queue_empty_lockless include/linux/skbuff.h:1891 [inline] skb_queue_purge_reason+0x99/0x360 net/core/skbuff.c:3937 skb_queue_purge include/linux/skbuff.h:3368 [inline] vhci_flush+0x44/0x50 drivers/bluetooth/hci_vhci.c:69 hci_dev_do_reset net/bluetooth/hci_core.c:552 [inline] hci_dev_reset+0x420/0x5c0 net/bluetooth/hci_core.c:592 sock_do_ioctl+0xd9/0x300 net/socket.c:1190 sock_ioctl+0x576/0x790 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcf5b98e929 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fcf5c7b9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fcf5bbb6160 RCX: 00007fcf5b98e929 RDX: 0000000000000000 RSI: 00000000400448cb RDI: 0000000000000009 RBP: 00007fcf5ba10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fcf5bbb6160 R15: 00007ffd6353d528 Allocated by task 6535: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4359 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] vhci_open+0x57/0x360 drivers/bluetooth/hci_vhci.c:635 misc_open+0x2bc/0x330 drivers/char/misc.c:161 chrdev_open+0x4c9/0x5e0 fs/char_dev.c:414 do_dentry_open+0xdf0/0x1970 fs/open.c:964 vfs_open+0x3b/0x340 fs/open.c:1094 do_open fs/namei.c:3887 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4046 do_filp_open+0x1fa/0x410 fs/namei.c:4073 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6535: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x18e/0x440 mm/slub.c:4842 vhci_release+0xbc/0xd0 drivers/bluetooth/hci_vhci.c:671 __fput+0x44c/0xa70 fs/file_table.c:465 task_work_run+0x1d1/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6ad/0x22e0 kernel/exit.c:955 do_group_exit+0x21c/0x2d0 kernel/exit.c:1104 __do_sys_exit_group kernel/exit.c:1115 [inline] __se_sys_exit_group kernel/exit.c:1113 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1113 x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88807cb8d800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 88 bytes inside of freed 1024-byte region [ffff88807cb8d800, ffff88807cb8dc00) Fixes: bf18c7118cf8 ("Bluetooth: vhci: Free driver_data on file release") Reported-by: syzbot+2faa4825e556199361f9@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=f62d64848fc4c7c30cd6 Signed-off-by: Kuniyuki Iwashima Acked-by: Paul Menzel Signed-off-by: Luiz Augusto von Dentz --- include/net/bluetooth/hci_core.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h index a760f05fa3fb..9fc8f544e20e 100644 --- a/include/net/bluetooth/hci_core.h +++ b/include/net/bluetooth/hci_core.h @@ -29,6 +29,7 @@ #include #include #include +#include #include #include @@ -347,6 +348,7 @@ struct adv_monitor { struct hci_dev { struct list_head list; + struct srcu_struct srcu; struct mutex lock; struct ida unset_handle_ida; -- cgit v1.2.3 From 22bbc1dcd0d6785fb390c41f0dd5b5e218d23bdd Mon Sep 17 00:00:00 2001 From: Stefano Garzarella Date: Mon, 23 Jun 2025 12:00:53 +0200 Subject: vsock/uapi: fix linux/vm_sockets.h userspace compilation errors MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If a userspace application just include will fail to build with the following errors: /usr/include/linux/vm_sockets.h:182:39: error: invalid application of ‘sizeof’ to incomplete type ‘struct sockaddr’ 182 | unsigned char svm_zero[sizeof(struct sockaddr) - | ^~~~~~ /usr/include/linux/vm_sockets.h:183:39: error: ‘sa_family_t’ undeclared here (not in a function) 183 | sizeof(sa_family_t) - | Include for userspace (guarded by ifndef __KERNEL__) where `struct sockaddr` and `sa_family_t` are defined. We already do something similar in and . Fixes: d021c344051a ("VSOCK: Introduce VM Sockets") Reported-by: Daan De Meyer Signed-off-by: Stefano Garzarella Link: https://patch.msgid.link/20250623100053.40979-1-sgarzare@redhat.com Signed-off-by: Jakub Kicinski --- include/uapi/linux/vm_sockets.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include') diff --git a/include/uapi/linux/vm_sockets.h b/include/uapi/linux/vm_sockets.h index ed07181d4eff..e05280e41522 100644 --- a/include/uapi/linux/vm_sockets.h +++ b/include/uapi/linux/vm_sockets.h @@ -17,6 +17,10 @@ #ifndef _UAPI_VM_SOCKETS_H #define _UAPI_VM_SOCKETS_H +#ifndef __KERNEL__ +#include /* for struct sockaddr and sa_family_t */ +#endif + #include #include -- cgit v1.2.3 From 9e6dd4c256d0774701637b958ba682eff4991277 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Tue, 24 Jun 2025 14:09:59 -0700 Subject: netlink: specs: mptcp: replace underscores with dashes in names We're trying to add a strict regexp for the name format in the spec. Underscores will not be allowed, dashes should be used instead. This makes no difference to C (codegen, if used, replaces special chars in names) but it gives more uniform naming in Python. Fixes: bc8aeb2045e2 ("Documentation: netlink: add a YAML spec for mptcp") Reviewed-by: Davide Caratti Reviewed-by: Donald Hunter Reviewed-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20250624211002.3475021-8-kuba@kernel.org Signed-off-by: Jakub Kicinski --- include/uapi/linux/mptcp_pm.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/uapi/linux/mptcp_pm.h b/include/uapi/linux/mptcp_pm.h index 84fa8a21dfd0..6ac84b2f636c 100644 --- a/include/uapi/linux/mptcp_pm.h +++ b/include/uapi/linux/mptcp_pm.h @@ -27,14 +27,14 @@ * token, rem_id. * @MPTCP_EVENT_SUB_ESTABLISHED: A new subflow has been established. 'error' * should not be set. Attributes: token, family, loc_id, rem_id, saddr4 | - * saddr6, daddr4 | daddr6, sport, dport, backup, if_idx [, error]. + * saddr6, daddr4 | daddr6, sport, dport, backup, if-idx [, error]. * @MPTCP_EVENT_SUB_CLOSED: A subflow has been closed. An error (copy of * sk_err) could be set if an error has been detected for this subflow. * Attributes: token, family, loc_id, rem_id, saddr4 | saddr6, daddr4 | - * daddr6, sport, dport, backup, if_idx [, error]. + * daddr6, sport, dport, backup, if-idx [, error]. * @MPTCP_EVENT_SUB_PRIORITY: The priority of a subflow has changed. 'error' * should not be set. Attributes: token, family, loc_id, rem_id, saddr4 | - * saddr6, daddr4 | daddr6, sport, dport, backup, if_idx [, error]. + * saddr6, daddr4 | daddr6, sport, dport, backup, if-idx [, error]. * @MPTCP_EVENT_LISTENER_CREATED: A new PM listener is created. Attributes: * family, sport, saddr4 | saddr6. * @MPTCP_EVENT_LISTENER_CLOSED: A PM listener is closed. Attributes: family, -- cgit v1.2.3