{"id":"CVE-2026-98524","state":"PUBLISHED","title":"rds: ib: Clear the sg list when mapping an MR fails","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nrds: ib: Clear the sg list when mapping an MR fails\n\nrds_ib_map_frmr() stores the caller's scatterlist in the MR before DMA\nmapping and registration can fail. On failure, __rds_rdma_map() unpins\nthe pages and frees the scatterlist, but rds_ib_free_frmr() can still\nreturn the MR to the pool with the stale pointer set.\n\nThis leaves the pool with a dangling scatterlist and can lead to local\nprivilege escalation. KASAN detects the resulting use-after-free when the\nMR is later torn down:\n\nBUG: KASAN: slab-use-after-free in __rds_ib_teardown_mr\nRead of size 8\n\nCall Trace:\n __rds_ib_teardown_mr\n rds_ib_unreg_frmr\n rds_ib_flush_mr_pool\n rds_ib_flush_mrs\n rds_free_mr\n rds_setsockopt\n\nStore the scatterlist in the MR only after DMA mapping succeeds. If DMA\nmapping fails, return directly while the MR fields remain clear; the caller\nkeeps ownership of the scatterlist and its pinned pages. If a later\nregistration step fails, unmap the scatterlist and clear the MR fields\nbefore returning.","publishedAt":"2026-10-18T15:17:41.420Z","updatedAt":"2026-10-24T14:09:17.970Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1659185fb4d0025835eb2058a141f0746c5cab00","status":"affected","lessThan":"1be3211e6ac77adbb1eac01314d989d243b32c59","versionType":"git"},{"version":"1659185fb4d0025835eb2058a141f0746c5cab00","status":"affected","lessThan":"c42d316163f89cd23de2f3e24558177a8c29bad8","versionType":"git"},{"version":"1659185fb4d0025835eb2058a141f0746c5cab00","status":"affected","lessThan":"8dca3c81344532a7f05edb3d12f31f3009410a90","versionType":"git"},{"version":"1659185fb4d0025835eb2058a141f0746c5cab00","status":"affected","lessThan":"49ba5ed0129906e0362c2e4b5e21c89b2a41e115","versionType":"git"},{"version":"1659185fb4d0025835eb2058a141f0746c5cab00","status":"affected","lessThan":"4468df5bcdef959fd96494e9968f323561a45f4c","versionType":"git"},{"version":"1659185fb4d0025835eb2058a141f0746c5cab00","status":"affected","lessThan":"e2ee0616260080376123997488b5cf8a3870b8d9","versionType":"git"},{"version":"1659185fb4d0025835eb2058a141f0746c5cab00","status":"affected","lessThan":"b36d32f30c3f1e58e3a5ae79d0f52836a316b36e","versionType":"git"},{"version":"1659185fb4d0025835eb2058a141f0746c5cab00","status":"affected","lessThan":"58eb1b3325edac42dc6df72c80962bd53a3c8ca7","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/rds/ib_frmr.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.6","versionType":"semver"},{"version":"5.10.271","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.222","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.189","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.112","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.55","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.9","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/rds/ib_frmr.c"]}],"references":["https://git.kernel.org/stable/c/1be3211e6ac77adbb1eac01314d989d243b32c59","https://git.kernel.org/stable/c/c42d316163f89cd23de2f3e24558177a8c29bad8","https://git.kernel.org/stable/c/8dca3c81344532a7f05edb3d12f31f3009410a90","https://git.kernel.org/stable/c/49ba5ed0129906e0362c2e4b5e21c89b2a41e115","https://git.kernel.org/stable/c/4468df5bcdef959fd96494e9968f323561a45f4c","https://git.kernel.org/stable/c/e2ee0616260080376123997488b5cf8a3870b8d9","https://git.kernel.org/stable/c/b36d32f30c3f1e58e3a5ae79d0f52836a316b36e","https://git.kernel.org/stable/c/58eb1b3325edac42dc6df72c80962bd53a3c8ca7"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98524.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98524","state":"PUBLISHED","datePublished":"2026-10-18T15:17:41.420Z","dateUpdated":"2026-10-24T14:09:17.970Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.355Z"},"containers":{"cna":{"title":"rds: ib: Clear the sg list when mapping an MR fails","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nrds: ib: Clear the sg list when mapping an MR fails\n\nrds_ib_map_frmr() stores the caller's scatterlist in the MR before DMA\nmapping and registration can fail. On failure, __rds_rdma_map() unpins\nthe pages and frees the scatterlist, but rds_ib_free_frmr() can still\nreturn the MR to the pool with the stale pointer set.\n\nThis leaves the pool with a dangling scatterlist and can lead to local\nprivilege escalation. KASAN detects the resulting use-after-free when the\nMR is later torn down:\n\nBUG: KASAN: slab-use-after-free in __rds_ib_teardown_mr\nRead of size 8\n\nCall Trace:\n __rds_ib_teardown_mr\n rds_ib_unreg_frmr\n rds_ib_flush_mr_pool\n rds_ib_flush_mrs\n rds_free_mr\n rds_setsockopt\n\nStore the scatterlist in the MR only after DMA mapping succeeds. If DMA\nmapping fails, return directly while the MR fields remain clear; the caller\nkeeps ownership of the scatterlist and its pinned pages. If a later\nregistration step fails, unmap the scatterlist and clear the MR fields\nbefore returning."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1659185fb4d0025835eb2058a141f0746c5cab00","status":"affected","lessThan":"1be3211e6ac77adbb1eac01314d989d243b32c59","versionType":"git"},{"version":"1659185fb4d0025835eb2058a141f0746c5cab00","status":"affected","lessThan":"c42d316163f89cd23de2f3e24558177a8c29bad8","versionType":"git"},{"version":"1659185fb4d0025835eb2058a141f0746c5cab00","status":"affected","lessThan":"8dca3c81344532a7f05edb3d12f31f3009410a90","versionType":"git"},{"version":"1659185fb4d0025835eb2058a141f0746c5cab00","status":"affected","lessThan":"49ba5ed0129906e0362c2e4b5e21c89b2a41e115","versionType":"git"},{"version":"1659185fb4d0025835eb2058a141f0746c5cab00","status":"affected","lessThan":"4468df5bcdef959fd96494e9968f323561a45f4c","versionType":"git"},{"version":"1659185fb4d0025835eb2058a141f0746c5cab00","status":"affected","lessThan":"e2ee0616260080376123997488b5cf8a3870b8d9","versionType":"git"},{"version":"1659185fb4d0025835eb2058a141f0746c5cab00","status":"affected","lessThan":"b36d32f30c3f1e58e3a5ae79d0f52836a316b36e","versionType":"git"},{"version":"1659185fb4d0025835eb2058a141f0746c5cab00","status":"affected","lessThan":"58eb1b3325edac42dc6df72c80962bd53a3c8ca7","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/rds/ib_frmr.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.6","versionType":"semver"},{"version":"5.10.271","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.222","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.189","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.112","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.55","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.9","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/rds/ib_frmr.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/1be3211e6ac77adbb1eac01314d989d243b32c59"},{"url":"https://git.kernel.org/stable/c/c42d316163f89cd23de2f3e24558177a8c29bad8"},{"url":"https://git.kernel.org/stable/c/8dca3c81344532a7f05edb3d12f31f3009410a90"},{"url":"https://git.kernel.org/stable/c/49ba5ed0129906e0362c2e4b5e21c89b2a41e115"},{"url":"https://git.kernel.org/stable/c/4468df5bcdef959fd96494e9968f323561a45f4c"},{"url":"https://git.kernel.org/stable/c/e2ee0616260080376123997488b5cf8a3870b8d9"},{"url":"https://git.kernel.org/stable/c/b36d32f30c3f1e58e3a5ae79d0f52836a316b36e"},{"url":"https://git.kernel.org/stable/c/58eb1b3325edac42dc6df72c80962bd53a3c8ca7"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The attacker reaches patched rds_ib_map_frmr() through sendmsg() with a local RDS_CMSG_RDMA_MAP control message; no RDS packet field from a remote peer supplies the scatterlist or faulty ownership state.\nAC:L - On HNS hardware, the attacker can start an outgoing RDS connection and retry sendmsg() while its QP is RESET/INIT/RTR; check_send_valid() makes hns_roce_v2_post_send() return -EINVAL to rds_ib_post_reg_frmr(), creating the required failure.\nPR:L - rds_create(), rds_bind(), and rds_sendmsg() impose no capability or authentication check, and __rds_rdma_map() accepts an unprivileged process whenever can_do_mlock() sees a nonzero RLIMIT_MEMLOCK; RDS/IB merely requires the host's initial network namespace.\nUI:N - The attacking process performs both RDS_CMSG_RDMA_MAP and the zero-cookie setsockopt(SOL_RDS, RDS_FREE_MR) that calls rds_ib_flush_mrs(); no victim action is required.\nS:U - The stale ibmr->sg is consumed by __rds_ib_teardown_mr() within the host kernel, so exploitation elevates authority inside that same kernel rather than crossing a VM, IOMMU, or other security boundary.\nC:H - __rds_ib_teardown_mr() obtains page pointers with sg_page() from a freed, reclaimable scatterlist; attacker-controlled reclamation and the subsequent invalid free can enable kernel-memory compromise and disclosure.\nI:H - Teardown passes page pointers taken from the stale scatterlist to unpin_user_pages_dirty_lock() and then kfree()s the already-freed or reallocated array, enabling page-refcount and heap corruption usable for arbitrary writes or control-flow takeover.\nA:H - The observed slab use-after-free occurs in __rds_ib_teardown_mr(); dereferencing an invalid sg_page(), unpinning the resulting bogus page, or freeing the dangling scatterlist can produce a kernel oops or panic."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-24T14:09:17.970Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"5.10.271"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"5.15.222"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.1.189"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.6.158"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.12.112"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.18.55"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"7.2.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}