Vulnerabilities > CVE-2024-26781 - Improper Locking vulnerability in multiple products

047910
CVSS 5.5 - MEDIUM
Attack vector
LOCAL
Attack complexity
LOW
Privileges required
LOW
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
HIGH
local
low complexity
linux
debian
CWE-667
NVD
Published: 2024-04-04
Updated: 2025-01-07

Summary

In the Linux kernel, the following vulnerability has been resolved: mptcp: fix possible deadlock in subflow diag Syzbot and Eric reported a lockdep splat in the subflow diag: WARNING: possible circular locking dependency detected 6.8.0-rc4-syzkaller-00212-g40b9385dd8e6 #0 Not tainted syz-executor.2/24141 is trying to acquire lock: ffff888045870130 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at: tcp_diag_put_ulp net/ipv4/tcp_diag.c:100 [inline] ffff888045870130 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at: tcp_diag_get_aux+0x738/0x830 net/ipv4/tcp_diag.c:137 but task is already holding lock: ffffc9000135e488 (&h->lhash2[i].lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffffc9000135e488 (&h->lhash2[i].lock){+.+.}-{2:2}, at: inet_diag_dump_icsk+0x39f/0x1f80 net/ipv4/inet_diag.c:1038 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&h->lhash2[i].lock){+.+.}-{2:2}: lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] __inet_hash+0x335/0xbe0 net/ipv4/inet_hashtables.c:743 inet_csk_listen_start+0x23a/0x320 net/ipv4/inet_connection_sock.c:1261 __inet_listen_sk+0x2a2/0x770 net/ipv4/af_inet.c:217 inet_listen+0xa3/0x110 net/ipv4/af_inet.c:239 rds_tcp_listen_init+0x3fd/0x5a0 net/rds/tcp_listen.c:316 rds_tcp_init_net+0x141/0x320 net/rds/tcp.c:577 ops_init+0x352/0x610 net/core/net_namespace.c:136 __register_pernet_operations net/core/net_namespace.c:1214 [inline] register_pernet_operations+0x2cb/0x660 net/core/net_namespace.c:1283 register_pernet_device+0x33/0x80 net/core/net_namespace.c:1370 rds_tcp_init+0x62/0xd0 net/rds/tcp.c:735 do_one_initcall+0x238/0x830 init/main.c:1236 do_initcall_level+0x157/0x210 init/main.c:1298 do_initcalls+0x3f/0x80 init/main.c:1314 kernel_init_freeable+0x42f/0x5d0 init/main.c:1551 kernel_init+0x1d/0x2a0 init/main.c:1441 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242 -> #0 (k-sk_lock-AF_INET6){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18ca/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 lock_sock_fast include/net/sock.h:1723 [inline] subflow_get_info+0x166/0xd20 net/mptcp/diag.c:28 tcp_diag_put_ulp net/ipv4/tcp_diag.c:100 [inline] tcp_diag_get_aux+0x738/0x830 net/ipv4/tcp_diag.c:137 inet_sk_diag_fill+0x10ed/0x1e00 net/ipv4/inet_diag.c:345 inet_diag_dump_icsk+0x55b/0x1f80 net/ipv4/inet_diag.c:1061 __inet_diag_dump+0x211/0x3a0 net/ipv4/inet_diag.c:1263 inet_diag_dump_compat+0x1c1/0x2d0 net/ipv4/inet_diag.c:1371 netlink_dump+0x59b/0xc80 net/netlink/af_netlink.c:2264 __netlink_dump_start+0x5df/0x790 net/netlink/af_netlink.c:2370 netlink_dump_start include/linux/netlink.h:338 [inline] inet_diag_rcv_msg_compat+0x209/0x4c0 net/ipv4/inet_diag.c:1405 sock_diag_rcv_msg+0xe7/0x410 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543 sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:280 netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1367 netlink_sendmsg+0xa3b/0xd70 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584 ___sys_sendmsg net/socket.c:2638 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 As noted by Eric we can break the lock dependency chain avoid dumping ---truncated---

Vulnerable Configurations

Part Description Count
OS
Linux
7
OS
Debian
1

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Leveraging Race Conditions
    This attack targets a race condition occurring when multiple processes access and manipulate the same resource concurrently and the outcome of the execution depends on the particular order in which the access takes place. The attacker can leverage a race condition by "running the race", modifying the resource and modifying the normal execution flow. For instance a race condition can occur while accessing a file, the attacker can trick the system by replacing the original file with his version and cause the system to read the malicious file.
  • Leveraging Race Conditions via Symbolic Links
    This attack leverages the use of symbolic links (Symlinks) in order to write to sensitive files. An attacker can create a Symlink link to a target file not otherwise accessible to her. When the privileged program tries to create a temporary file with the same name as the Symlink link, it will actually write to the target file pointed to by the attackers' Symlink link. If the attacker can insert malicious content in the temporary file she will be writing to the sensitive file by using the Symlink. The race occurs because the system checks if the temporary file exists, then creates the file. The attacker would typically create the Symlink during the interval between the check and the creation of the temporary file.

References