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mirror of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-09-04 20:19:47 +08:00
linux/net
Kuniyuki Iwashima ec79003c5f atm: atmtcp: Prevent arbitrary write in atmtcp_recv_control().
syzbot reported the splat below. [0]

When atmtcp_v_open() or atmtcp_v_close() is called via connect()
or close(), atmtcp_send_control() is called to send an in-kernel
special message.

The message has ATMTCP_HDR_MAGIC in atmtcp_control.hdr.length.
Also, a pointer of struct atm_vcc is set to atmtcp_control.vcc.

The notable thing is struct atmtcp_control is uAPI but has a
space for an in-kernel pointer.

  struct atmtcp_control {
  	struct atmtcp_hdr hdr;	/* must be first */
  ...
  	atm_kptr_t vcc;		/* both directions */
  ...
  } __ATM_API_ALIGN;

  typedef struct { unsigned char _[8]; } __ATM_API_ALIGN atm_kptr_t;

The special message is processed in atmtcp_recv_control() called
from atmtcp_c_send().

atmtcp_c_send() is vcc->dev->ops->send() and called from 2 paths:

  1. .ndo_start_xmit() (vcc->send() == atm_send_aal0())
  2. vcc_sendmsg()

The problem is sendmsg() does not validate the message length and
userspace can abuse atmtcp_recv_control() to overwrite any kptr
by atmtcp_control.

Let's add a new ->pre_send() hook to validate messages from sendmsg().

[0]:
Oops: general protection fault, probably for non-canonical address 0xdffffc00200000ab: 0000 [#1] SMP KASAN PTI
KASAN: probably user-memory-access in range [0x0000000100000558-0x000000010000055f]
CPU: 0 UID: 0 PID: 5865 Comm: syz-executor331 Not tainted 6.17.0-rc1-syzkaller-00215-gbab3ce404553 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:atmtcp_recv_control drivers/atm/atmtcp.c:93 [inline]
RIP: 0010:atmtcp_c_send+0x1da/0x950 drivers/atm/atmtcp.c:297
Code: 4d 8d 75 1a 4c 89 f0 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 15 06 00 00 41 0f b7 1e 4d 8d b7 60 05 00 00 4c 89 f0 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 13 06 00 00 66 41 89 1e 4d 8d 75 1c 4c
RSP: 0018:ffffc90003f5f810 EFLAGS: 00010203
RAX: 00000000200000ab RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88802a510000 RSI: 00000000ffffffff RDI: ffff888030a6068c
RBP: ffff88802699fb40 R08: ffff888030a606eb R09: 1ffff1100614c0dd
R10: dffffc0000000000 R11: ffffffff8718fc40 R12: dffffc0000000000
R13: ffff888030a60680 R14: 000000010000055f R15: 00000000ffffffff
FS:  00007f8d7e9236c0(0000) GS:ffff888125c1c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000045ad50 CR3: 0000000075bde000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 vcc_sendmsg+0xa10/0xc60 net/atm/common.c:645
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x219/0x270 net/socket.c:729
 ____sys_sendmsg+0x505/0x830 net/socket.c:2614
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
 __sys_sendmsg net/socket.c:2700 [inline]
 __do_sys_sendmsg net/socket.c:2705 [inline]
 __se_sys_sendmsg net/socket.c:2703 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703
 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: 0033:0x7f8d7e96a4a9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 18 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8d7e923198 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f8d7e9f4308 RCX: 00007f8d7e96a4a9
RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000005
RBP: 00007f8d7e9f4300 R08: 65732f636f72702f R09: 65732f636f72702f
R10: 65732f636f72702f R11: 0000000000000246 R12: 00007f8d7e9c10ac
R13: 00007f8d7e9231a0 R14: 0000200000000200 R15: 0000200000000250
 </TASK>
Modules linked in:

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: syzbot+1741b56d54536f4ec349@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/68a6767c.050a0220.3d78fd.0011.GAE@google.com/
Tested-by: syzbot+1741b56d54536f4ec349@syzkaller.appspotmail.com
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250821021901.2814721-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-22 17:23:15 -07:00
..
6lowpan net: replace ND_PRINTK with dynamic debug 2025-07-10 15:27:32 -07:00
9p netfs: Fix the request's work item to not require a ref 2025-05-21 14:35:20 +02:00
802 treewide, timers: Rename from_timer() to timer_container_of() 2025-06-08 09:07:37 +02:00
8021q net: s/dev_close_many/netif_close_many/ 2025-07-18 17:27:47 -07:00
appletalk Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2025-07-24 11:10:46 -07:00
atm atm: atmtcp: Prevent arbitrary write in atmtcp_recv_control(). 2025-08-22 17:23:15 -07:00
ax25 treewide, timers: Rename from_timer() to timer_container_of() 2025-06-08 09:07:37 +02:00
batman-adv This cleanup patchset includes the following patches: 2025-07-11 17:50:27 -07:00
bluetooth Bluetooth: hci_sync: fix set_local_name race condition 2025-08-22 13:57:31 -04:00
bpf bpf: Add attach_type field to bpf_link 2025-07-11 10:51:55 -07:00
bridge net: bridge: fix soft lockup in br_multicast_query_expired() 2025-08-14 17:49:33 -07:00
caif caif: reduce stack size, again 2025-06-23 16:58:43 -07:00
can Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2025-06-12 10:09:10 -07:00
ceph libceph: Rename hmac_sha256() to ceph_hmac_sha256() 2025-07-04 10:18:52 -07:00
core page_pool: fix incorrect mp_ops error handling 2025-08-22 15:52:02 -07:00
dcb
devlink devlink: let driver opt out of automatic phys_port_name generation 2025-08-12 13:23:39 -07:00
dns_resolver
dsa net: s/dev_close_many/netif_close_many/ 2025-07-18 17:27:47 -07:00
ethernet
ethtool ethtool: rss: support removing contexts via Netlink 2025-07-21 18:21:19 -07:00
handshake net/handshake: Add new parameter 'HANDSHAKE_A_ACCEPT_KEYRING' 2025-07-08 15:31:44 +02:00
hsr net, hsr: reject HSR frame if skb can't hold tag 2025-08-20 19:31:25 -07:00
ieee802154 treewide, timers: Rename from_timer() to timer_container_of() 2025-06-08 09:07:37 +02:00
ife
ipv4 netfilter: nf_reject: don't leak dst refcount for loopback packets 2025-08-21 10:02:00 -07:00
ipv6 netfilter: nf_reject: don't leak dst refcount for loopback packets 2025-08-21 10:02:00 -07:00
iucv s390/drivers: Explicitly include <linux/export.h> 2025-06-17 18:18:02 +02:00
kcm net: kcm: Fix race condition in kcm_unattach() 2025-08-13 18:18:33 -07:00
key Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2025-07-24 11:10:46 -07:00
l2tp net: annotate races around sk->sk_uid 2025-06-23 17:04:03 -07:00
l3mdev net: fib_rules: Fix iif / oif matching on L3 master device 2025-04-15 17:54:56 -07:00
lapb treewide, timers: Rename from_timer() to timer_container_of() 2025-06-08 09:07:37 +02:00
llc net: make sk->sk_rcvtimeo lockless 2025-06-23 17:05:12 -07:00
mac80211 wifi: mac80211: fix WARN_ON for monitor mode on some devices 2025-07-23 12:29:07 +02:00
mac802154
mctp net: mctp: Fix bad kfree_skb in bind lookup test 2025-08-13 17:07:34 -07:00
mpls net: s/dev_get_flags/netif_get_flags/ 2025-07-18 17:27:47 -07:00
mptcp mptcp: disable add_addr retransmission when timeout is 0 2025-08-18 17:39:58 -07:00
ncsi net: ncsi: Fix buffer overflow in fetching version id 2025-06-12 18:21:59 -07:00
netfilter netfilter: nf_tables: reject duplicate device on updates 2025-08-13 08:34:55 +02:00
netlabel calipso: unlock rcu before returning -EAFNOSUPPORT 2025-06-05 08:03:38 -07:00
netlink netlink: avoid infinite retry looping in netlink_unicast() 2025-07-30 19:16:49 -07:00
netrom treewide, timers: Rename from_timer() to timer_container_of() 2025-06-08 09:07:37 +02:00
nfc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2025-06-19 13:00:24 -07:00
nsh
openvswitch net: openvswitch: allow providing upcall pid for the 'execute' command 2025-07-07 14:30:39 -07:00
packet net/packet: fix a race in packet_set_ring() and packet_notifier() 2025-08-04 17:21:27 -07:00
phonet Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2025-07-17 11:00:33 -07:00
psample
qrtr
rds don't open-code kernel_accept() in rds_tcp_accept_one() 2025-07-15 16:19:54 -07:00
rfkill
rose net: track pfmemalloc drops via SKB_DROP_REASON_PFMEMALLOC 2025-07-18 16:59:05 -07:00
rxrpc rxrpc: Fix to use conn aborts for conn-wide failures 2025-07-17 07:50:48 -07:00
sched net/sched: Remove unnecessary WARNING condition for empty child qdisc in htb_activate 2025-08-20 19:27:08 -07:00
sctp sctp: linearize cloned gso packets in sctp_rcv 2025-08-08 13:08:06 -07:00
shaper
smc net/smc: fix UAF on smcsk after smc_listen_out() 2025-08-19 18:27:16 -07:00
strparser net: make sk->sk_rcvtimeo lockless 2025-06-23 17:05:12 -07:00
sunrpc nfsd-6.17 fixes: 2025-08-11 07:38:55 -07:00
switchdev
tipc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2025-07-10 10:10:49 -07:00
tls tls: fix handling of zero-length records on the rx_list 2025-08-21 07:52:30 -07:00
unix Networking changes for 6.17. 2025-07-30 08:58:55 -07:00
vmw_vsock vsock/virtio: Fix message iterator handling on transmit path 2025-08-21 17:49:19 -07:00
wireless Another wireless update: 2025-07-24 17:25:42 -07:00
x25 net/x25: Remove unused x25_terminate_link() 2025-07-14 17:19:13 -07:00
xdp net: xsk: introduce XDP_MAX_TX_SKB_BUDGET setsockopt 2025-07-10 14:48:29 +02:00
xfrm xfrm: bring back device check in validate_xmit_xfrm 2025-08-07 08:07:01 +02:00
compat.c
devres.c
Kconfig net: Kconfig: add endif/endmenu comments 2025-07-22 18:17:23 -07:00
Kconfig.debug
Makefile net: Retire DCCP socket. 2025-04-11 18:58:10 -07:00
socket.c net: annotate races around sk->sk_uid 2025-06-23 17:04:03 -07:00
sysctl_net.c