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.c
br_arp_nd_proxy.c
br_cfm.c
br_cfm_netlink.c
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
br_forward.c	net: bridge: mst: Check vlan state for egress decision	2024-07-15 13:40:28 +01:00
br_if.c
br_input.c
br_ioctl.c
br_mdb.c
br_mrp.c
br_mrp_netlink.c
br_mrp_switchdev.c
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.c	net: bridge: mcast: wait for previous gc cycles when removing port	2024-08-05 16:33:56 -07:00
br_multicast_eht.c
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
br_netlink.c
br_netlink_tunnel.c	net: bridge: fix an inconsistent indentation	2024-06-05 10:04:47 +01:00
br_nf_core.c
br_private.h
br_private_cfm.h
br_private_mcast_eht.h
br_private_mrp.h
br_private_stp.h
br_private_tunnel.h
br_stp.c
br_stp_bpdu.c
br_stp_if.c
br_stp_timer.c
br_switchdev.c
br_sysfs_br.c
br_sysfs_if.c
br_vlan.c
br_vlan_options.c
br_vlan_tunnel.c
Kconfig
Makefile