{"cve":"CVE-2021-47249","nvd":{"published":"2024-05-21T15:15:13.857","modified":"2026-06-17T04:17:00.713","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: rds: fix memory leak in rds_recvmsg\n\nSyzbot reported memory leak in rds. The problem\nwas in unputted refcount in case of error.\n\nint rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,\n\t\tint msg_flags)\n{\n...\n\n\tif (!rds_next_incoming(rs, &inc)) {\n\t\t...\n\t}\n\nAfter this \"if\" inc refcount incremented and\n\n\tif (rds_cmsg_recv(inc, msg, rs)) {\n\t\tret = -EFAULT;\n\t\tgoto out;\n\t}\n...\nout:\n\treturn ret;\n}\n\nin case of rds_cmsg_recv() fail the refcount won't be\ndecremented. And it's easy to see from ftrace log, that\nrds_inc_addref() don't have rds_inc_put() pair in\nrds_recvmsg() after rds_cmsg_recv()\n\n 1)               |  rds_recvmsg() {\n 1)   3.721 us    |    rds_inc_addref();\n 1)   3.853 us    |    rds_message_inc_copy_to_user();\n 1) + 10.395 us   |    rds_cmsg_recv();\n 1) + 34.260 us   |  }","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-401"],"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"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:50:30.954589733+00:00"},"epss":{"cve":"CVE-2021-47249","score":0.00236,"percentile":0.14682,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}