linux/net/bridge
Nikolay Aleksandrov 92c4ee2520 net: bridge: mcast: wait for previous gc cycles when removing port
syzbot hit a use-after-free[1] which is caused because the bridge doesn't
make sure that all previous garbage has been collected when removing a
port. What happens is:
      CPU 1                   CPU 2
 start gc cycle           remove port
                         acquire gc lock first
 wait for lock
                         call br_multicasg_gc() directly
 acquire lock now but    free port
 the port can be freed
 while grp timers still
 running

Make sure all previous gc cycles have finished by using flush_work before
freeing the port.

[1]
  BUG: KASAN: slab-use-after-free in br_multicast_port_group_expired+0x4c0/0x550 net/bridge/br_multicast.c:861
  Read of size 8 at addr ffff888071d6d000 by task syz.5.1232/9699

  CPU: 1 PID: 9699 Comm: syz.5.1232 Not tainted 6.10.0-rc5-syzkaller-00021-g24ca36a562d6 #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
  Call Trace:
   <IRQ>
   __dump_stack lib/dump_stack.c:88 [inline]
   dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
   print_address_description mm/kasan/report.c:377 [inline]
   print_report+0xc3/0x620 mm/kasan/report.c:488
   kasan_report+0xd9/0x110 mm/kasan/report.c:601
   br_multicast_port_group_expired+0x4c0/0x550 net/bridge/br_multicast.c:861
   call_timer_fn+0x1a3/0x610 kernel/time/timer.c:1792
   expire_timers kernel/time/timer.c:1843 [inline]
   __run_timers+0x74b/0xaf0 kernel/time/timer.c:2417
   __run_timer_base kernel/time/timer.c:2428 [inline]
   __run_timer_base kernel/time/timer.c:2421 [inline]
   run_timer_base+0x111/0x190 kernel/time/timer.c:2437

Reported-by: syzbot+263426984509be19c9a0@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=263426984509be19c9a0
Fixes: e12cec65b5 ("net: bridge: mcast: destroy all entries via gc")
Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20240802080730.3206303-1-razor@blackwall.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-05 16:33:56 -07:00
..
netfilter net: Rename mono_delivery_time to tstamp_type for scalabilty 2024-05-23 14:14:23 -07:00
br_arp_nd_proxy.c bridge: Add per-{Port, VLAN} neighbor suppression data path support 2023-04-21 08:25:50 +01:00
br_cfm_netlink.c bridge: cfm: fix enum typo in br_cc_ccm_tx_parse 2023-12-26 22:38:13 +00:00
br_cfm.c bridge: cfm: remove redundant return 2021-06-22 10:35:15 -07:00
br_device.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2024-05-15 07:30:49 -07:00
br_fdb.c net: bridge: Use KMEM_CACHE instead of kmem_cache_create 2024-01-31 16:39:46 -08:00
br_forward.c net: bridge: mst: Check vlan state for egress decision 2024-07-15 13:40:28 +01:00
br_if.c net: bridge: keep ports without IFF_UNICAST_FLT in BR_PROMISC mode 2023-07-03 09:11:34 +01:00
br_input.c netfilter: br_netfilter: skip conntrack input hook for promisc packets 2024-04-11 12:09:33 +02:00
br_ioctl.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-12-31 14:35:40 +00:00
br_mdb.c bridge: mdb: Add MDB bulk deletion support 2023-12-20 11:27:20 +00:00
br_mrp_netlink.c bridge: mrp: Use hlist_head instead of list_head for mrp 2020-11-09 16:42:12 -08:00
br_mrp_switchdev.c bridge: mrp: Extend br_mrp_switchdev to detect better the errors 2021-02-16 14:47:46 -08:00
br_mrp.c net: bridge: mrp: Update the Test frames for MRA 2021-06-28 15:46:10 -07:00
br_mst.c net: bridge: mst: fix suspicious rcu usage in br_mst_set_state 2024-06-12 18:24:24 -07:00
br_multicast_eht.c treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
br_multicast.c net: bridge: mcast: wait for previous gc cycles when removing port 2024-08-05 16:33:56 -07:00
br_netfilter_hooks.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
br_netfilter_ipv6.c netfilter: bridge: replace physindev with physinif in nf_bridge_info 2024-01-17 12:02:49 +01:00
br_netlink_tunnel.c net: bridge: fix an inconsistent indentation 2024-06-05 10:04:47 +01:00
br_netlink.c bridge/br_netlink.c: no need to return void function 2024-04-22 11:57:14 +01:00
br_nf_core.c net: dst: Switch to rcuref_t reference counting 2023-03-28 18:52:28 -07:00
br_private_cfm.h bridge: cfm: Kernel space implementation of CFM. CCM frame RX added. 2020-10-29 18:39:43 -07:00
br_private_mcast_eht.h net: bridge: multicast: use multicast contexts instead of bridge or port 2021-07-20 05:41:19 -07:00
br_private_mrp.h net: bridge: mrp: Update the Test frames for MRA 2021-06-28 15:46:10 -07:00
br_private_stp.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
br_private_tunnel.h bridge: always declare tunnel functions 2023-05-17 21:28:58 -07:00
br_private.h netfilter: br_netfilter: skip conntrack input hook for promisc packets 2024-04-11 12:09:33 +02:00
br_stp_bpdu.c net: bridge: add STP xstats 2019-12-14 20:02:36 -08:00
br_stp_if.c net: use eth_hw_addr_set() 2021-10-02 14:18:25 +01:00
br_stp_timer.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
br_stp.c net: bridge: mst: Multiple Spanning Tree (MST) mode 2022-03-17 16:49:57 -07:00
br_switchdev.c net: bridge: switchdev: Ensure deferred event delivery on unoffload 2024-02-16 09:36:37 +00:00
br_sysfs_br.c bridge: Fix flushing of dynamic FDB entries 2022-11-02 20:47:09 -07:00
br_sysfs_if.c bridge: move from strlcpy with unused retval to strscpy 2022-08-22 17:57:30 -07:00
br_vlan_options.c bridge: vlan: Allow setting VLAN neighbor suppression state 2023-04-21 08:25:50 +01:00
br_vlan_tunnel.c ip_tunnel: convert __be16 tunnel flags to bitmaps 2024-04-01 10:49:28 +01:00
br_vlan.c bridge: vlan: use synchronize_net() when holding RTNL 2024-02-12 12:17:02 +00:00
br.c bridge: use exit_batch_rtnl() method 2024-02-07 18:55:12 -08:00
Kconfig bridge: cfm: Add BRIDGE_CFM to Kconfig. 2020-10-29 18:39:43 -07:00
Makefile net: bridge: mst: Multiple Spanning Tree (MST) mode 2022-03-17 16:49:57 -07:00