Kuniyuki Iwashima 64ae2a8641 can: bcm: Remove proc entry when dev is unregistered. ... [ Upstream commit 76fe372ccb81b0c89b6cd2fec26e2f38c958be85 ] syzkaller reported a warning in bcm_connect() below. [0] The repro calls connect() to vxcan1, removes vxcan1, and calls connect() with ifindex == 0. Calling connect() for a BCM socket allocates a proc entry. Then, bcm_sk(sk)->bound is set to 1 to prevent further connect(). However, removing the bound device resets bcm_sk(sk)->bound to 0 in bcm_notify(). The 2nd connect() tries to allocate a proc entry with the same name and sets NULL to bcm_sk(sk)->bcm_proc_read, leaking the original proc entry. Since the proc entry is available only for connect()ed sockets, let's clean up the entry when the bound netdev is unregistered. [0]: proc_dir_entry 'can-bcm/2456' already registered WARNING: CPU: 1 PID: 394 at fs/proc/generic.c:376 proc_register+0x645/0x8f0 fs/proc/generic.c:375 Modules linked in: CPU: 1 PID: 394 Comm: syz-executor403 Not tainted 6.10.0-rc7-g852e42cc2dd4 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 RIP: 0010:proc_register+0x645/0x8f0 fs/proc/generic.c:375 Code: 00 00 00 00 00 48 85 ed 0f 85 97 02 00 00 4d 85 f6 0f 85 9f 02 00 00 48 c7 c7 9b cb cf 87 48 89 de 4c 89 fa e8 1c 6f eb fe 90 <0f> 0b 90 90 48 c7 c7 98 37 99 89 e8 cb 7e 22 05 bb 00 00 00 10 48 RSP: 0018:ffa0000000cd7c30 EFLAGS: 00010246 RAX: 9e129be1950f0200 RBX: ff1100011b51582c RCX: ff1100011857cd80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002 RBP: 0000000000000000 R08: ffd400000000000f R09: ff1100013e78cac0 R10: ffac800000cd7980 R11: ff1100013e12b1f0 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ff1100011a99a2ec FS: 00007fbd7086f740(0000) GS:ff1100013fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000200071c0 CR3: 0000000118556004 CR4: 0000000000771ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> proc_create_net_single+0x144/0x210 fs/proc/proc_net.c:220 bcm_connect+0x472/0x840 net/can/bcm.c:1673 __sys_connect_file net/socket.c:2049 [inline] __sys_connect+0x5d2/0x690 net/socket.c:2066 __do_sys_connect net/socket.c:2076 [inline] __se_sys_connect net/socket.c:2073 [inline] __x64_sys_connect+0x8f/0x100 net/socket.c:2073 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd9/0x1c0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7fbd708b0e5d Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 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 8b 0d 73 9f 1b 00 f7 d8 64 89 01 48 RSP: 002b:00007fff8cd33f08 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fbd708b0e5d RDX: 0000000000000010 RSI: 0000000020000040 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000040 R09: 0000000000000040 R10: 0000000000000040 R11: 0000000000000246 R12: 00007fff8cd34098 R13: 0000000000401280 R14: 0000000000406de8 R15: 00007fbd70ab9000 </TASK> remove_proc_entry: removing non-empty directory 'net/can-bcm', leaking at least '2456' Fixes: ffd980f976e7 ("[CAN]: Add broadcast manager (bcm) protocol") Reported-by: syzkaller <syzkaller@googlegroups.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://lore.kernel.org/all/20240722192842.37421-1-kuniyu@amazon.com Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Sasha Levin <sashal@kernel.org>		2025-01-19 00:10:01 +01:00
..
6lowpan
9p	9p/xen: fix release of IRQ	2024-12-17 13:24:22 +01:00
802
8021q	gro: remove rcu_read_lock/rcu_read_unlock from gro_receive handlers	2025-01-19 00:10:01 +01:00
appletalk
atm
ax25	Revert "Make more sysctl constants read-only"	2024-12-03 19:56:17 +01:00
batman-adv	batman-adv: Do not let TT changes list grows indefinitely	2025-01-02 17:00:49 +01:00
bluetooth	Bluetooth: L2CAP: do not leave dangling sk pointer on error in l2cap_sock_create()	2024-12-17 13:24:30 +01:00
bpf
bpfilter
bridge	net: bridge: br_fdb_external_learn_add(): always set EXT_LEARN	2025-01-19 00:10:01 +01:00
caif
can	can: bcm: Remove proc entry when dev is unregistered.	2025-01-19 00:10:01 +01:00
ceph	libceph: fix race between delayed_work() and ceph_monc_stop()	2024-11-19 14:19:45 +01:00
core	Revert "skb_expand_head() adjust skb->truesize incorrectly"	2025-01-15 16:38:33 +01:00
dcb
dccp	dccp: Fix memory leak in dccp_feat_change_recv	2024-12-17 13:24:26 +01:00
decnet
dns_resolver
dsa
ethernet	gro: remove rcu_read_lock/rcu_read_unlock from gro_receive handlers	2025-01-19 00:10:01 +01:00
ethtool	ethtool: Fix wrong mod state in case of verbose and no_mask bitset	2024-12-17 13:24:27 +01:00
hsr	net: hsr: avoid potential out-of-bound access in fill_frame_info()	2024-12-17 13:24:26 +01:00
ieee802154	net: ieee802154: do not leave a dangling sk pointer in ieee802154_create()	2024-12-17 13:24:30 +01:00
ife
ipv4	tcp_bpf: fix return value of tcp_bpf_sendmsg()	2025-01-19 00:10:01 +01:00
ipv6	gro: remove rcu_read_lock/rcu_read_unlock from gro_receive handlers	2025-01-19 00:10:01 +01:00
iucv	Revert "net/iucv: fix use after free in iucv_sock_close()"	2024-11-24 00:23:55 +01:00
kcm	kcm: Serialise kcm_sendmsg() for the same socket.	2024-11-23 23:20:48 +01:00
key
l2tp	genetlink: hold RCU in genlmsg_mcast()	2024-11-23 23:21:59 +01:00
l3mdev	net: Add l3mdev index to flow struct and avoid oif reset for port devices	2024-11-23 23:21:52 +01:00
lapb
llc	net: llc: reset skb->transport_header	2025-01-15 16:29:53 +01:00
mac80211	wifi: mac80211: wake the queues in case of failure in resume	2025-01-15 16:29:54 +01:00
mac802154	Revert "net: mac802154: Fix racy device stats updates by DEV_STATS_INC() and DEV_STATS_ADD()"	2024-11-19 14:52:14 +01:00
mpls
mptcp	Revert "mptcp: correct MPTCP_SUBFLOW_ATTR_SSN_OFFSET reserved size"	2024-11-24 00:23:53 +01:00
ncm
ncsi	net/ncsi: Fix the multi thread manner of NCSI driver	2024-11-19 14:19:00 +01:00
netfilter	netfilter: ipset: Fix for recursive locking warning	2025-01-15 16:29:41 +01:00
netlabel
netlink	netlink: terminate outstanding dump on socket close	2024-12-17 13:20:50 +01:00
netrom	netrom: check buffer length before accessing it	2025-01-15 16:29:53 +01:00
nfc
nsh
openvswitch
packet	af_packet: fix vlan_get_protocol_dgram() vs MSG_PEEK	2025-01-15 16:29:54 +01:00
phonet	Revert "Make more sysctl constants read-only"	2024-12-03 19:56:17 +01:00
psample
qrtr	Revert "net: qrtr: Update packets cloning when broadcasting"	2024-11-24 00:23:18 +01:00
rds	Revert "net:rds: Fix possible deadlock in rds_message_put"	2024-11-24 00:23:49 +01:00
rfkill	net: rfkill: gpio: Add check for clk_enable()	2024-12-17 13:24:07 +01:00
rose	Revert "Make more sysctl constants read-only"	2024-12-03 19:56:17 +01:00
rxrpc
sched	BACKPORT: netem: fix return value if duplicate enqueue fails	2025-01-19 00:09:58 +01:00
sctp	net/sctp: Prevent autoclose integer overflow in sctp_association_init()	2025-01-15 16:29:56 +01:00
skb_tracer
smc	net/smc: check return value of sock_recvmsg when draining clc data	2025-01-15 16:29:41 +01:00
strparser
sunrpc	svcrdma: Catch another Reply chunk overflow case	2025-01-19 00:10:01 +01:00
switchdev
tipc	tipc: fix NULL deref in cleanup_bearer()	2025-01-02 17:00:49 +01:00
tls
unix	Revert "af_unix: Remove put_pid()/put_cred() in copy_peercred()."	2024-11-24 00:23:43 +01:00
vmw_vsock	virtio/vsock: Fix accept_queue memory leak	2025-01-02 17:00:49 +01:00
wimax
wireless	Revert "wifi: nl80211: don't give key data to userspace"	2024-11-24 00:23:55 +01:00
x25	Revert "Make more sysctl constants read-only"	2024-12-03 19:56:17 +01:00
xdp
xfrm	xfrm: store and rely on direction to construct offload flags	2024-12-17 13:24:04 +01:00
compat.c
devres.c
Kconfig
Makefile
socket.c
sysctl_net.c
TEST_MAPPING