{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-39857","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2025-04-16T07:20:57.142Z","datePublished":"2025-09-19T15:26:28.225Z","dateUpdated":"2026-08-05T12:05:40.229Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T12:05:40.229Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: fix one NULL pointer dereference in smc_ib_is_sg_need_sync()\n\nBUG: kernel NULL pointer dereference, address: 00000000000002ec\nPGD 0 P4D 0\nOops: Oops: 0000 [#1] SMP PTI\nCPU: 28 UID: 0 PID: 343 Comm: kworker/28:1 Kdump: loaded Tainted: G        OE       6.17.0-rc2+ #9 NONE\nTainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014\nWorkqueue: smc_hs_wq smc_listen_work [smc]\nRIP: 0010:smc_ib_is_sg_need_sync+0x9e/0xd0 [smc]\n...\nCall Trace:\n <TASK>\n smcr_buf_map_link+0x211/0x2a0 [smc]\n __smc_buf_create+0x522/0x970 [smc]\n smc_buf_create+0x3a/0x110 [smc]\n smc_find_rdma_v2_device_serv+0x18f/0x240 [smc]\n ? smc_vlan_by_tcpsk+0x7e/0xe0 [smc]\n smc_listen_find_device+0x1dd/0x2b0 [smc]\n smc_listen_work+0x30f/0x580 [smc]\n process_one_work+0x18c/0x340\n worker_thread+0x242/0x360\n kthread+0xe7/0x220\n ret_from_fork+0x13a/0x160\n ret_from_fork_asm+0x1a/0x30\n </TASK>\n\nIf the software RoCE device is used, ibdev->dma_device is a null pointer.\nAs a result, the problem occurs. Null pointer detection is added to\nprevent problems."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - The crash is triggered by a remote peer's TCP connection plus a CLC Proposal message to an SMC-enabled listening socket, processed in smc_listen_work() on the smc_hs_wq workqueue. The triggering traffic is ordinary routable TCP (no RDMA fabric traffic is required to reach the fault), so any internet-reachable SMC server is exposed.\nAC:L - On an affected system (SMC-R backed by a soft-RoCE/rxe or siw device, a supported and commonly used configuration) the NULL dereference is hit unconditionally on the first SMC-R buffer mapping — no race, no heap grooming, no memory-layout dependency. The attacker fully controls the proposal fields that steer the server down the SMC-R v2 device path.\nPR:N - The entire path runs inside the CLC handshake worker before accept() returns to userspace, and SMC performs no authentication of the peer whatsoever. There are no capability checks anywhere in net/smc along this path.\nUI:N - The server-side handshake worker processes the attacker's connection automatically with no action by any local user or administrator.\nS:U - The fault and its consequences are confined to the kernel's own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:N - The fault is a read of NULL+0x2ec (page fault error code 0000) that aborts immediately; no data is returned to the attacker and no out-of-bounds memory is disclosed.\nI:N - No memory is written and no attacker-controlled data corrupts kernel state — the dereference faults before dma_need_sync() can act.\nA:H - The NULL dereference oopses the smc_hs_wq kworker, killing it while it holds smc_server_lgr_pending and the socket lock, so the SMC subsystem deadlocks permanently for every later connection; with panic_on_oops the whole system panics, and the attacker can repeat it unauthenticated at will."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/smc/smc_ib.c"],"versions":[{"version":"0ef69e788411cba2af017db731a9fc62d255e9ac","lessThan":"0cdf1fd8fc59d44a48c694324611136910301ef9","status":"affected","versionType":"git"},{"version":"0ef69e788411cba2af017db731a9fc62d255e9ac","lessThan":"f18d9b3abf9c6587372cc702f963a7592277ed56","status":"affected","versionType":"git"},{"version":"0ef69e788411cba2af017db731a9fc62d255e9ac","lessThan":"eb929910bd4b4165920fa06a87b22cc6cae92e0e","status":"affected","versionType":"git"},{"version":"0ef69e788411cba2af017db731a9fc62d255e9ac","lessThan":"34f17cbe027050b8d5316ea1b6f9bd7c378e92de","status":"affected","versionType":"git"},{"version":"0ef69e788411cba2af017db731a9fc62d255e9ac","lessThan":"ba1e9421cf1a8369d25c3832439702a015d6b5f9","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/smc/smc_ib.c"],"versions":[{"version":"6.0","status":"affected"},{"version":"0","lessThan":"6.0","status":"unaffected","versionType":"semver"},{"version":"6.1.151","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.105","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.46","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.16.6","lessThanOrEqual":"6.16.*","status":"unaffected","versionType":"semver"},{"version":"6.17","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.1.151"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.6.105"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.12.46"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.16.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.17"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/0cdf1fd8fc59d44a48c694324611136910301ef9"},{"url":"https://git.kernel.org/stable/c/f18d9b3abf9c6587372cc702f963a7592277ed56"},{"url":"https://git.kernel.org/stable/c/eb929910bd4b4165920fa06a87b22cc6cae92e0e"},{"url":"https://git.kernel.org/stable/c/34f17cbe027050b8d5316ea1b6f9bd7c378e92de"},{"url":"https://git.kernel.org/stable/c/ba1e9421cf1a8369d25c3832439702a015d6b5f9"}],"title":"net/smc: fix one NULL pointer dereference in smc_ib_is_sg_need_sync()","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"}],"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2025-11-03T17:44:10.731Z"}},{"x_adpType":"supplier","providerMetadata":{"orgId":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e","shortName":"siemens-SADP","dateUpdated":"2026-05-12T12:07:40.683Z"},"affected":[{"vendor":"Siemens","product":"SIMATIC CN 4100","versions":[{"status":"affected","version":"0","lessThan":"V5.0","versionType":"custom"}],"defaultStatus":"unknown"}],"references":[{"url":"https://cert-portal.siemens.com/productcert/html/ssa-032379.html"}]}]}}