CVE-2021-47249
What it is
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() 1) | rds_recvmsg() { 1) 3.721 us | rds_inc_addref(); 1) 3.853 us | rds_message_inc_copy_to_user(); 1) + 10.395 us | rds_cmsg_recv(); 1) + 34.260 us | }
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 5.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Weakness
- CWE-401
- Record status
- Analyzed
Affected
- Linux Kernel < 4.4.274
- Linux Kernel < 4.9.274
- Linux Kernel < 4.14.238
- Linux Kernel < 4.19.196
- Linux Kernel < 5.4.128
- Linux Kernel < 5.10.46
- Linux Kernel < 5.12.13
- Linux Kernel 5.13
Attack profile CVSS 3.1 · 5.5
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2021-47249.md and follow it. Check whether this project is affected by CVE-2021-47249. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/06b7cb0194bd1ede0dd27f3a946e7c0279fba44a
- https://git.kernel.org/stable/c/1f79bc8ae81c05eb112a53f981cb2c244ee50d02
- https://git.kernel.org/stable/c/2038cd15eacdf7512755c27686822e0052eb9042
- https://git.kernel.org/stable/c/423c6939758fb3b9cf5abbd1e7792068a5c4ae8c
- https://git.kernel.org/stable/c/49bfcbfd989a8f1f23e705759a6bb099de2cff9f
- https://git.kernel.org/stable/c/5946fbf48355f5a8caeff72580c7658da5966b86
- https://git.kernel.org/stable/c/8c3ec88b03e9e4ca117dcdc4204fd3edcd02084f
- https://git.kernel.org/stable/c/b25b60d076164edb3025e85aabd2cf50a5215b91
- https://git.kernel.org/stable/c/06b7cb0194bd1ede0dd27f3a946e7c0279fba44a
- https://git.kernel.org/stable/c/1f79bc8ae81c05eb112a53f981cb2c244ee50d02
References
- https://git.kernel.org/stable/c/06b7cb0194bd1ede0dd27f3a946e7c0279fba44a
- https://git.kernel.org/stable/c/1f79bc8ae81c05eb112a53f981cb2c244ee50d02
- https://git.kernel.org/stable/c/2038cd15eacdf7512755c27686822e0052eb9042
- https://git.kernel.org/stable/c/423c6939758fb3b9cf5abbd1e7792068a5c4ae8c
- https://git.kernel.org/stable/c/49bfcbfd989a8f1f23e705759a6bb099de2cff9f
- https://git.kernel.org/stable/c/5946fbf48355f5a8caeff72580c7658da5966b86
- https://git.kernel.org/stable/c/8c3ec88b03e9e4ca117dcdc4204fd3edcd02084f
- https://git.kernel.org/stable/c/b25b60d076164edb3025e85aabd2cf50a5215b91
- https://git.kernel.org/stable/c/06b7cb0194bd1ede0dd27f3a946e7c0279fba44a
- https://git.kernel.org/stable/c/1f79bc8ae81c05eb112a53f981cb2c244ee50d02
- https://git.kernel.org/stable/c/2038cd15eacdf7512755c27686822e0052eb9042
- https://git.kernel.org/stable/c/423c6939758fb3b9cf5abbd1e7792068a5c4ae8c
- https://git.kernel.org/stable/c/49bfcbfd989a8f1f23e705759a6bb099de2cff9f
- https://git.kernel.org/stable/c/5946fbf48355f5a8caeff72580c7658da5966b86
- https://git.kernel.org/stable/c/8c3ec88b03e9e4ca117dcdc4204fd3edcd02084f
- https://git.kernel.org/stable/c/b25b60d076164edb3025e85aabd2cf50a5215b91