CVE-2025-68787 netrom: Fix memory leak in nr_sendmsg()
A memory leak in the Linux kernel's netrom module allows local attackers to exhaust system memory, causing denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-68787?
CVE-2025-68787 is a memory corruption vulnerability in Linux, published on 13 Jan 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
netrom: Fix memory leak in nr_sendmsg()
syzbot reported a memory leak [1].
When function sock_alloc_send_skb() return NULL in nr_output(), the original skb is not freed, which was allocated in nr_sendmsg(). Fix this by freeing it before return.
[1] BUG: memory leak unreferenced object 0xffff888129f35500 (size 240): comm "syz.0.17", pid 6119, jiffies 4294944652 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 10 52 28 81 88 ff ff ..........R(.... backtrace (crc 1456a3e4): kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline] slab_post_alloc_hook mm/slub.c:4983 [inline] slab_alloc_node mm/slub.c:5288 [inline] kmem_cache_alloc_node_noprof+0x36f/0x5e0 mm/slub.c:5340 __alloc_skb+0x203/0x240 net/core/skbuff.c:660 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0x69/0x3f0 net/core/skbuff.c:6671 sock_alloc_send_pskb+0x379/0x3e0 net/core/sock.c:2965 sock_alloc_send_skb include/net/sock.h:1859 [inline] nr_sendmsg+0x287/0x450 net/netrom/af_netrom.c:1105 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] sock_write_iter+0x293/0x2a0 net/socket.c:1195 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x45d/0x710 fs/read_write.c:686 ksys_write+0x143/0x170 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xa4/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f
Which versions are affected by CVE-2025-68787?
How do I fix CVE-2025-68787?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-68787 being exploited?
There is no known exploitation of CVE-2025-68787 in the wild and no public exploit code.
Sources
Also known as AZL-74390, BELL-CVE-2025-68787, DEBIAN-CVE-2025-68787, GHSA-6prc-rrx9-j93r, ROOT-OS-DEBIAN-11-CVE-2025-68787, ROOT-OS-DEBIAN-12-CVE-2025-68787 and 4 more.