{"id":"CVE-2021-47215","state":"PUBLISHED","title":"net/mlx5e: kTLS, Fix crash in RX resync flow","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: kTLS, Fix crash in RX resync flow\n\nFor the TLS RX resync flow, we maintain a list of TLS contexts\nthat require some attention, to communicate their resync information\nto the HW.\nHere we fix list corruptions, by protecting the entries against\nmovements coming from resync_handle_seq_match(), until their resync\nhandling in napi is fully completed.","publishedAt":"2024-04-10T19:01:55.157Z","updatedAt":"2026-08-05T08:46:45.596Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/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":"e9ce991bce5bacf71641bd0f72f4b7c589529f40","status":"affected","lessThan":"ebeda7a9528ae690e6bf12791a868f0cca8391f2","versionType":"git"},{"version":"e9ce991bce5bacf71641bd0f72f4b7c589529f40","status":"affected","lessThan":"cc4a9cc03faa6d8db1a6954bb536f2c1e63bdff6","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_rx.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.13","versionType":"semver"},{"version":"5.15.5","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"5.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_rx.c"]}],"references":["https://git.kernel.org/stable/c/ebeda7a9528ae690e6bf12791a868f0cca8391f2","https://git.kernel.org/stable/c/cc4a9cc03faa6d8db1a6954bb536f2c1e63bdff6"],"weaknesses":[],"ingestedAt":"2026-10-29T19:49:19.404Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2021/47xxx/CVE-2021-47215.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2021-47215","state":"PUBLISHED","datePublished":"2024-04-10T19:01:55.157Z","dateUpdated":"2026-08-05T08:46:45.596Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-04-10T18:59:19.528Z"},"containers":{"cna":{"title":"net/mlx5e: kTLS, Fix crash in RX resync flow","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: kTLS, Fix crash in RX resync flow\n\nFor the TLS RX resync flow, we maintain a list of TLS contexts\nthat require some attention, to communicate their resync information\nto the HW.\nHere we fix list corruptions, by protecting the entries against\nmovements coming from resync_handle_seq_match(), until their resync\nhandling in napi is fully completed."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e9ce991bce5bacf71641bd0f72f4b7c589529f40","status":"affected","lessThan":"ebeda7a9528ae690e6bf12791a868f0cca8391f2","versionType":"git"},{"version":"e9ce991bce5bacf71641bd0f72f4b7c589529f40","status":"affected","lessThan":"cc4a9cc03faa6d8db1a6954bb536f2c1e63bdff6","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_rx.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.13","versionType":"semver"},{"version":"5.15.5","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"5.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_rx.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/ebeda7a9528ae690e6bf12791a868f0cca8391f2"},{"url":"https://git.kernel.org/stable/c/cc4a9cc03faa6d8db1a6954bb536f2c1e63bdff6"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - The buggy path is mlx5e kTLS RX resync (mlx5e_ktls_rx_resync → resync_handle_seq_match), invoked from the TLS stack when processing records from a remote peer after the NIC signals CQE_TLS_OFFLOAD_RESYNC; kTLS bugs driven by remote peer data are Network per guidance.\nAC:L - A remote peer can induce HW stream desync (reorder/loss/stream-scan) and then flood TLS records so multiple seq-match callbacks re-add the same priv_rx while it remains on the resync or NAPI local list; the attacker drives both the match callbacks and the RX/NAPI activity that opens the window.\nPR:N - Triggering requires only connecting as a TLS client to a service that has installed kTLS RX hardware offload on an mlx5 NIC; no local OS privileges or authenticated kernel credentials are needed.\nUI:N - The victim need only already be serving TLS with mlx5 kTLS RX offload; the attacker alone completes the handshake and drives the resync/race traffic with no further user action.\nS:U - List corruption stays within host kernel heap/list state for the mlx5e/TLS offload contexts and does not cross a VM, IOMMU, or other separate security authority.\nC:H - Double list_add of an in-list node corrupts neighboring list pointers and yields classic heap UAF when those links are later walked, which can be groomed for arbitrary kernel memory disclosure.\nI:H - Subsequent list_del/list_move/splice through the corrupted pointers write into attacker-influenced addresses, providing a heap corruption and control-flow hijack primitive beyond a mere crash.\nA:H - The fix explicitly addresses a crash from list corruption in the RX resync flow; corrupted list walks produce kernel oops/BUG (list_debug) that fully disrupt host availability."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T08:46:45.596Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"5.15.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"5.16"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/ebeda7a9528ae690e6bf12791a868f0cca8391f2","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/cc4a9cc03faa6d8db1a6954bb536f2c1e63bdff6","tags":["x_transferred"]}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2024-08-04T05:32:07.443Z"}},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2021-47215","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-09-10T15:49:52.131087Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-09-11T17:32:56.486Z"}}]}}}