{"id":"CVE-2025-40083","state":"PUBLISHED","title":"net/sched: sch_qfq: Fix null-deref in agg_dequeue","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: sch_qfq: Fix null-deref in agg_dequeue\n\nTo prevent a potential crash in agg_dequeue (net/sched/sch_qfq.c)\nwhen cl->qdisc->ops->peek(cl->qdisc) returns NULL, we check the return\nvalue before using it, similar to the existing approach in sch_hfsc.c.\n\nTo avoid code duplication, the following changes are made:\n\n1. Changed qdisc_warn_nonwc(include/net/pkt_sched.h) into a static\ninline function.\n\n2. Moved qdisc_peek_len from net/sched/sch_hfsc.c to\ninclude/net/pkt_sched.h so that sch_qfq can reuse it.\n\n3. Applied qdisc_peek_len in agg_dequeue to avoid crashing.","publishedAt":"2025-10-29T13:37:01.868Z","updatedAt":"2026-06-16T19:43:09.432Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"462dbc9101acd38e92eda93c0726857517a24bbd","status":"affected","lessThan":"71d84658a61322e5630c85c5388fc25e4a2d08b2","versionType":"git"},{"version":"462dbc9101acd38e92eda93c0726857517a24bbd","status":"affected","lessThan":"99fc137f178797204d36ac860dd8b31e35baa2df","versionType":"git"},{"version":"462dbc9101acd38e92eda93c0726857517a24bbd","status":"affected","lessThan":"1bed56f089f09b465420bf23bb32985c305cfc28","versionType":"git"},{"version":"462dbc9101acd38e92eda93c0726857517a24bbd","status":"affected","lessThan":"3c2a8994807623c7655ece205667ae2cf74940aa","versionType":"git"},{"version":"462dbc9101acd38e92eda93c0726857517a24bbd","status":"affected","lessThan":"6ffa9d66187188e3068b5a3895e6ae1ee34f9199","versionType":"git"},{"version":"462dbc9101acd38e92eda93c0726857517a24bbd","status":"affected","lessThan":"6ff8e74c8f8a68ec07ef837b95425dfe900d060f","versionType":"git"},{"version":"462dbc9101acd38e92eda93c0726857517a24bbd","status":"affected","lessThan":"dd831ac8221e691e9e918585b1003c7071df0379","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/net/pkt_sched.h","net/sched/sch_api.c","net/sched/sch_hfsc.c","net/sched/sch_qfq.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.8","versionType":"semver"},{"version":"5.4.302","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.247","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.197","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.159","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.116","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.57","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/net/pkt_sched.h","net/sched/sch_api.c","net/sched/sch_hfsc.c","net/sched/sch_qfq.c"]}],"references":["https://git.kernel.org/stable/c/71d84658a61322e5630c85c5388fc25e4a2d08b2","https://git.kernel.org/stable/c/99fc137f178797204d36ac860dd8b31e35baa2df","https://git.kernel.org/stable/c/1bed56f089f09b465420bf23bb32985c305cfc28","https://git.kernel.org/stable/c/3c2a8994807623c7655ece205667ae2cf74940aa","https://git.kernel.org/stable/c/6ffa9d66187188e3068b5a3895e6ae1ee34f9199","https://git.kernel.org/stable/c/6ff8e74c8f8a68ec07ef837b95425dfe900d060f","https://git.kernel.org/stable/c/dd831ac8221e691e9e918585b1003c7071df0379"],"weaknesses":[],"ingestedAt":"2026-10-29T20:09:09.358Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/40xxx/CVE-2025-40083.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-40083","state":"PUBLISHED","datePublished":"2025-10-29T13:37:01.868Z","dateUpdated":"2026-06-16T19:43:09.432Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-04-16T07:20:57.161Z"},"containers":{"cna":{"title":"net/sched: sch_qfq: Fix null-deref in agg_dequeue","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: sch_qfq: Fix null-deref in agg_dequeue\n\nTo prevent a potential crash in agg_dequeue (net/sched/sch_qfq.c)\nwhen cl->qdisc->ops->peek(cl->qdisc) returns NULL, we check the return\nvalue before using it, similar to the existing approach in sch_hfsc.c.\n\nTo avoid code duplication, the following changes are made:\n\n1. Changed qdisc_warn_nonwc(include/net/pkt_sched.h) into a static\ninline function.\n\n2. Moved qdisc_peek_len from net/sched/sch_hfsc.c to\ninclude/net/pkt_sched.h so that sch_qfq can reuse it.\n\n3. Applied qdisc_peek_len in agg_dequeue to avoid crashing."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"462dbc9101acd38e92eda93c0726857517a24bbd","status":"affected","lessThan":"71d84658a61322e5630c85c5388fc25e4a2d08b2","versionType":"git"},{"version":"462dbc9101acd38e92eda93c0726857517a24bbd","status":"affected","lessThan":"99fc137f178797204d36ac860dd8b31e35baa2df","versionType":"git"},{"version":"462dbc9101acd38e92eda93c0726857517a24bbd","status":"affected","lessThan":"1bed56f089f09b465420bf23bb32985c305cfc28","versionType":"git"},{"version":"462dbc9101acd38e92eda93c0726857517a24bbd","status":"affected","lessThan":"3c2a8994807623c7655ece205667ae2cf74940aa","versionType":"git"},{"version":"462dbc9101acd38e92eda93c0726857517a24bbd","status":"affected","lessThan":"6ffa9d66187188e3068b5a3895e6ae1ee34f9199","versionType":"git"},{"version":"462dbc9101acd38e92eda93c0726857517a24bbd","status":"affected","lessThan":"6ff8e74c8f8a68ec07ef837b95425dfe900d060f","versionType":"git"},{"version":"462dbc9101acd38e92eda93c0726857517a24bbd","status":"affected","lessThan":"dd831ac8221e691e9e918585b1003c7071df0379","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/net/pkt_sched.h","net/sched/sch_api.c","net/sched/sch_hfsc.c","net/sched/sch_qfq.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.8","versionType":"semver"},{"version":"5.4.302","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.247","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.197","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.159","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.116","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.57","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/net/pkt_sched.h","net/sched/sch_api.c","net/sched/sch_hfsc.c","net/sched/sch_qfq.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/71d84658a61322e5630c85c5388fc25e4a2d08b2"},{"url":"https://git.kernel.org/stable/c/99fc137f178797204d36ac860dd8b31e35baa2df"},{"url":"https://git.kernel.org/stable/c/1bed56f089f09b465420bf23bb32985c305cfc28"},{"url":"https://git.kernel.org/stable/c/3c2a8994807623c7655ece205667ae2cf74940aa"},{"url":"https://git.kernel.org/stable/c/6ffa9d66187188e3068b5a3895e6ae1ee34f9199"},{"url":"https://git.kernel.org/stable/c/6ff8e74c8f8a68ec07ef837b95425dfe900d060f"},{"url":"https://git.kernel.org/stable/c/dd831ac8221e691e9e918585b1003c7071df0379"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T21:42:10.831Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"5.4.302"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"5.10.247"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"5.15.197"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"6.1.159"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"6.6.116"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"6.12.57"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"6.16"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-16T19:42:58.130867Z","id":"CVE-2025-40083","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-06-16T19:43:09.432Z"}}]}}}