Shigeru Yoshida 3f14457e15 net: caif: Fix use-after-free in cfusbl_device_notify() ... [ Upstream commit 9781e98a97 ] syzbot reported use-after-free in cfusbl_device_notify() [1]. This causes a stack trace like below: BUG: KASAN: use-after-free in cfusbl_device_notify+0x7c9/0x870 net/caif/caif_usb.c:138 Read of size 8 at addr ffff88807ac4e6f0 by task kworker/u4:6/1214 CPU: 0 PID: 1214 Comm: kworker/u4:6 Not tainted 5.19.0-rc3-syzkaller-00146-g92f20ff72066 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0xeb/0x467 mm/kasan/report.c:313 print_report mm/kasan/report.c:429 [inline] kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491 cfusbl_device_notify+0x7c9/0x870 net/caif/caif_usb.c:138 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1945 call_netdevice_notifiers_extack net/core/dev.c:1983 [inline] call_netdevice_notifiers net/core/dev.c:1997 [inline] netdev_wait_allrefs_any net/core/dev.c:10227 [inline] netdev_run_todo+0xbc0/0x10f0 net/core/dev.c:10341 default_device_exit_batch+0x44e/0x590 net/core/dev.c:11334 ops_exit_list+0x125/0x170 net/core/net_namespace.c:167 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:594 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302 </TASK> When unregistering a net device, unregister_netdevice_many_notify() sets the device's reg_state to NETREG_UNREGISTERING, calls notifiers with NETDEV_UNREGISTER, and adds the device to the todo list. Later on, devices in the todo list are processed by netdev_run_todo(). netdev_run_todo() waits devices' reference count become 1 while rebdoadcasting NETDEV_UNREGISTER notification. When cfusbl_device_notify() is called with NETDEV_UNREGISTER multiple times, the parent device might be freed. This could cause UAF. Processing NETDEV_UNREGISTER multiple times also causes inbalance of reference count for the module. This patch fixes the issue by accepting only first NETDEV_UNREGISTER notification. Fixes: 7ad65bf68d ("caif: Add support for CAIF over CDC NCM USB interface") CC: sjur.brandeland@stericsson.com <sjur.brandeland@stericsson.com> Reported-by: syzbot+b563d33852b893653a9e@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=c3bfd8e2450adab3bffe4d80821fbbced600407f [1] Signed-off-by: Shigeru Yoshida <syoshida@redhat.com> Link: https://lore.kernel.org/r/20230301163913.391304-1-syoshida@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>		2023-03-17 08:48:54 +01:00
..
caif_dev.c	net: caif: fix memory leak in caif_device_notify	2021-06-03 15:05:07 -07:00
caif_socket.c	net: Remove WARN_ON_ONCE(sk->sk_forward_alloc) from sk_stream_kill_queues().	2023-03-03 11:45:53 +01:00
caif_usb.c	net: caif: Fix use-after-free in cfusbl_device_notify()	2023-03-17 08:48:54 +01:00
cfcnfg.c	net: caif: modify the label out_err to out	2021-06-18 12:07:09 -07:00
cfctrl.c	caif: fix memory leak in cfctrl_linkup_request()	2023-01-12 11:59:16 +01:00
cfdbgl.c
cfdgml.c
cffrml.c
cfmuxl.c
cfpkt_skbuff.c
cfrfml.c	net: caif: fix error code handling	2020-08-25 07:50:25 -07:00
cfserl.c	net: caif: added cfserl_release function	2021-06-03 15:05:06 -07:00
cfsrvl.c	caif: Remove duplicate macro SRVL_CTRL_PKT_SIZE	2020-09-05 15:57:05 -07:00
cfutill.c
cfveil.c
cfvidl.c
chnl_net.c	net: caif: fix double disconnect client in chnl_net_open()	2022-11-26 09:24:39 +01:00
Kconfig	treewide: replace '---help---' in Kconfig files with 'help'	2020-06-14 01:57:21 +09:00
Makefile