CVE-2021-47249

2024-05-2115:15:13

416baaa9-dc9f-4396-8d5f-8c081fb06d67

web.nvd.nist.gov

linux kernel vulnerability

net rds fix

memory leak

syzbot report

refcount error

rds_recvmsg fix

ftrace log

nvd

6.6 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

13.0%

JSON

In the Linux kernel, the following vulnerability has been resolved:

net: rds: fix memory leak in rds_recvmsg

Syzbot reported memory leak in rds. The problem
was in unputted refcount in case of error.

int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
int msg_flags)
{
…

if (!rds_next_incoming(rs, &inc)) {
	...
}

After this “if” inc refcount incremented and

if (rds_cmsg_recv(inc, msg, rs)) {
	ret = -EFAULT;
	goto out;
}

…
out:
return ret;
}

in case of rds_cmsg_recv() fail the refcount won’t be
decremented. And it’s easy to see from ftrace log, that
rds_inc_addref() don’t have rds_inc_put() pair in
rds_recvmsg() after rds_cmsg_recv()

```
          |  rds_recvmsg() {
```
3.721 us | rds_inc_addref();
3.853 us | rds_message_inc_copy_to_user();
- 10.395 us | rds_cmsg_recv();
- 34.260 us | }

Affected configurations

Vulners

Node

linuxlinux_kernelRange2.6.30–4.4.274

linuxlinux_kernelRange4.5.0–4.9.274

linuxlinux_kernelRange4.10.0–4.14.238

linuxlinux_kernelRange4.15.0–4.19.196

linuxlinux_kernelRange4.20.0–5.4.128

linuxlinux_kernelRange5.5.0–5.10.46

linuxlinux_kernelRange5.11.0–5.12.13

linuxlinux_kernelRange5.13.0≥

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/rds/recv.c"
    ],
    "versions": [
      {
        "version": "bdbe6fbc6a2f",
        "lessThan": "8c3ec88b03e9",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "bdbe6fbc6a2f",
        "lessThan": "423c6939758f",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "bdbe6fbc6a2f",
        "lessThan": "1f79bc8ae81c",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "bdbe6fbc6a2f",
        "lessThan": "06b7cb0194bd",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "bdbe6fbc6a2f",
        "lessThan": "2038cd15eacd",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "bdbe6fbc6a2f",
        "lessThan": "5946fbf48355",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "bdbe6fbc6a2f",
        "lessThan": "b25b60d07616",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "bdbe6fbc6a2f",
        "lessThan": "49bfcbfd989a",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/rds/recv.c"
    ],
    "versions": [
      {
        "version": "2.6.30",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "2.6.30",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.4.274",
        "lessThanOrEqual": "4.4.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.9.274",
        "lessThanOrEqual": "4.9.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.14.238",
        "lessThanOrEqual": "4.14.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.19.196",
        "lessThanOrEqual": "4.19.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.4.128",
        "lessThanOrEqual": "5.4.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.10.46",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.12.13",
        "lessThanOrEqual": "5.12.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.13",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]