{"id":"CVE-2026-98801","state":"PUBLISHED","title":"net: restrict SO_RESERVE_MEM to TCP sockets and cap max value","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: restrict SO_RESERVE_MEM to TCP sockets and cap max value\n\nCommit 2bb2f5fb21b0 (\"net: add new socket option SO_RESERVE_MEM\") and\ncommit d00c8ee31729 (\"net: fix possible NULL deref in sock_reserve_memory\")\nonly checked sk_has_account(sk), which is true for both TCP and UDP\nsockets.\n\nHowever, SO_RESERVE_MEM and sk_unused_reserved_mem() are currently only\nsupported by TCP:\n- On UDP sockets, sk->sk_forward_alloc is protected by\n  sk->sk_receive_queue.lock, whereas sock_reserve_memory() and\n  sock_release_reserved_memory() only acquire lock_sock(sk). Concurrent\n  UDP packet reception/release and setsockopt(SO_RESERVE_MEM) corrupt\n  sk_forward_alloc and memcg accounting.\n- udp_rmem_release() reclaims excess sk_forward_alloc without\n  accounting for sk_unused_reserved_mem(sk).\n\nRestrict sock_reserve_memory() to TCP sockets (sk_is_tcp(sk)) for now.\nSupporting SO_RESERVE_MEM for UDP (acquiring sk_receive_queue.lock and\nhonoring sk_unused_reserved_mem() in udp_rmem_release()) can be done in\na future net-next series if needed.\n\nIn addition, reject val > SZ_1G with -EINVAL in\nsk_setsockopt(SO_RESERVE_MEM). Without an upper bound, values near\nINT_MAX cause sk_mem_pages(delta) and (pages << PAGE_SHIFT) to overflow\n32-bit signed int, corrupting sk->sk_forward_alloc and\nsk->sk_reserved_mem. Using a page-aligned cap (SZ_1G) ensures that the\npage-rounded sk->sk_reserved_mem reported by getsockopt(SO_RESERVE_MEM)\ncan always be passed back to setsockopt(SO_RESERVE_MEM).","publishedAt":"2026-10-18T15:48:47.171Z","updatedAt":"2026-10-19T09:25:54.691Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"2bb2f5fb21b0486ff69b7b4a1fe03a760527d133","status":"affected","lessThan":"492e04f9a00f3cc88a1f6899417b10f3019a624e","versionType":"git"},{"version":"2bb2f5fb21b0486ff69b7b4a1fe03a760527d133","status":"affected","lessThan":"5069ce898148bd799395c5a464e006cbb840f188","versionType":"git"},{"version":"2bb2f5fb21b0486ff69b7b4a1fe03a760527d133","status":"affected","lessThan":"a467b05b201b5c26be52ed3081992fa9c0387648","versionType":"git"},{"version":"2bb2f5fb21b0486ff69b7b4a1fe03a760527d133","status":"affected","lessThan":"37e02c42a00be692c06343e11779aadc45f45971","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/sock.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.16","versionType":"semver"},{"version":"6.12.113","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.56","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.10","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/sock.c"]}],"references":["https://git.kernel.org/stable/c/492e04f9a00f3cc88a1f6899417b10f3019a624e","https://git.kernel.org/stable/c/5069ce898148bd799395c5a464e006cbb840f188","https://git.kernel.org/stable/c/a467b05b201b5c26be52ed3081992fa9c0387648","https://git.kernel.org/stable/c/37e02c42a00be692c06343e11779aadc45f45971"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98801.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98801","state":"PUBLISHED","datePublished":"2026-10-18T15:48:47.171Z","dateUpdated":"2026-10-19T09:25:54.691Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.370Z"},"containers":{"cna":{"title":"net: restrict SO_RESERVE_MEM to TCP sockets and cap max value","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: restrict SO_RESERVE_MEM to TCP sockets and cap max value\n\nCommit 2bb2f5fb21b0 (\"net: add new socket option SO_RESERVE_MEM\") and\ncommit d00c8ee31729 (\"net: fix possible NULL deref in sock_reserve_memory\")\nonly checked sk_has_account(sk), which is true for both TCP and UDP\nsockets.\n\nHowever, SO_RESERVE_MEM and sk_unused_reserved_mem() are currently only\nsupported by TCP:\n- On UDP sockets, sk->sk_forward_alloc is protected by\n  sk->sk_receive_queue.lock, whereas sock_reserve_memory() and\n  sock_release_reserved_memory() only acquire lock_sock(sk). Concurrent\n  UDP packet reception/release and setsockopt(SO_RESERVE_MEM) corrupt\n  sk_forward_alloc and memcg accounting.\n- udp_rmem_release() reclaims excess sk_forward_alloc without\n  accounting for sk_unused_reserved_mem(sk).\n\nRestrict sock_reserve_memory() to TCP sockets (sk_is_tcp(sk)) for now.\nSupporting SO_RESERVE_MEM for UDP (acquiring sk_receive_queue.lock and\nhonoring sk_unused_reserved_mem() in udp_rmem_release()) can be done in\na future net-next series if needed.\n\nIn addition, reject val > SZ_1G with -EINVAL in\nsk_setsockopt(SO_RESERVE_MEM). Without an upper bound, values near\nINT_MAX cause sk_mem_pages(delta) and (pages << PAGE_SHIFT) to overflow\n32-bit signed int, corrupting sk->sk_forward_alloc and\nsk->sk_reserved_mem. Using a page-aligned cap (SZ_1G) ensures that the\npage-rounded sk->sk_reserved_mem reported by getsockopt(SO_RESERVE_MEM)\ncan always be passed back to setsockopt(SO_RESERVE_MEM)."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"2bb2f5fb21b0486ff69b7b4a1fe03a760527d133","status":"affected","lessThan":"492e04f9a00f3cc88a1f6899417b10f3019a624e","versionType":"git"},{"version":"2bb2f5fb21b0486ff69b7b4a1fe03a760527d133","status":"affected","lessThan":"5069ce898148bd799395c5a464e006cbb840f188","versionType":"git"},{"version":"2bb2f5fb21b0486ff69b7b4a1fe03a760527d133","status":"affected","lessThan":"a467b05b201b5c26be52ed3081992fa9c0387648","versionType":"git"},{"version":"2bb2f5fb21b0486ff69b7b4a1fe03a760527d133","status":"affected","lessThan":"37e02c42a00be692c06343e11779aadc45f45971","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/sock.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.16","versionType":"semver"},{"version":"6.12.113","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.56","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.10","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/sock.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/492e04f9a00f3cc88a1f6899417b10f3019a624e"},{"url":"https://git.kernel.org/stable/c/5069ce898148bd799395c5a464e006cbb840f188"},{"url":"https://git.kernel.org/stable/c/a467b05b201b5c26be52ed3081992fa9c0387648"},{"url":"https://git.kernel.org/stable/c/37e02c42a00be692c06343e11779aadc45f45971"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:25:54.691Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16","versionEndExcluding":"6.12.113"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16","versionEndExcluding":"6.18.56"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16","versionEndExcluding":"7.2.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}