{"id":"CVE-2021-47439","state":"PUBLISHED","title":"net: dsa: microchip: Added the condition for scheduling ksz_mib_read_work","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: dsa: microchip: Added the condition for scheduling ksz_mib_read_work\n\nWhen the ksz module is installed and removed using rmmod, kernel crashes\nwith null pointer dereferrence error. During rmmod, ksz_switch_remove\nfunction tries to cancel the mib_read_workqueue using\ncancel_delayed_work_sync routine and unregister switch from dsa.\n\nDuring dsa_unregister_switch it calls ksz_mac_link_down, which in turn\nreschedules the workqueue since mib_interval is non-zero.\nDue to which queue executed after mib_interval and it tries to access\ndp->slave. But the slave is unregistered in the ksz_switch_remove\nfunction. Hence kernel crashes.\n\nTo avoid this crash, before canceling the workqueue, resetted the\nmib_interval to 0.\n\nv1 -> v2:\n-Removed the if condition in ksz_mib_read_work","publishedAt":"2024-05-22T06:19:34.192Z","updatedAt":"2026-05-11T13:54:43.614Z","severity":{"score":5.5,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","source":"CISA-ADP"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"469b390e1ba330e888175e55d78573db2e9a8cb4","status":"affected","lessThan":"f2e1de075018cf71bcd7d628e9f759cb8540b0c3","versionType":"git"},{"version":"469b390e1ba330e888175e55d78573db2e9a8cb4","status":"affected","lessThan":"383239a33cf29ebee9ce0d4e0e5c900b77a16148","versionType":"git"},{"version":"469b390e1ba330e888175e55d78573db2e9a8cb4","status":"affected","lessThan":"ef1100ef20f29aec4e62abeccdb5bdbebba1e378","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/dsa/microchip/ksz_common.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.7","versionType":"semver"},{"version":"5.10.75","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.14.14","status":"unaffected","lessThanOrEqual":"5.14.*","versionType":"semver"},{"version":"5.15","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/dsa/microchip/ksz_common.c"]}],"references":["https://git.kernel.org/stable/c/f2e1de075018cf71bcd7d628e9f759cb8540b0c3","https://git.kernel.org/stable/c/383239a33cf29ebee9ce0d4e0e5c900b77a16148","https://git.kernel.org/stable/c/ef1100ef20f29aec4e62abeccdb5bdbebba1e378"],"weaknesses":[],"ingestedAt":"2026-10-29T19:49:19.404Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2021/47xxx/CVE-2021-47439.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2021-47439","state":"PUBLISHED","datePublished":"2024-05-22T06:19:34.192Z","dateUpdated":"2026-05-11T13:54:43.614Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-05-21T14:58:30.831Z"},"containers":{"cna":{"title":"net: dsa: microchip: Added the condition for scheduling ksz_mib_read_work","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: dsa: microchip: Added the condition for scheduling ksz_mib_read_work\n\nWhen the ksz module is installed and removed using rmmod, kernel crashes\nwith null pointer dereferrence error. During rmmod, ksz_switch_remove\nfunction tries to cancel the mib_read_workqueue using\ncancel_delayed_work_sync routine and unregister switch from dsa.\n\nDuring dsa_unregister_switch it calls ksz_mac_link_down, which in turn\nreschedules the workqueue since mib_interval is non-zero.\nDue to which queue executed after mib_interval and it tries to access\ndp->slave. But the slave is unregistered in the ksz_switch_remove\nfunction. Hence kernel crashes.\n\nTo avoid this crash, before canceling the workqueue, resetted the\nmib_interval to 0.\n\nv1 -> v2:\n-Removed the if condition in ksz_mib_read_work"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"469b390e1ba330e888175e55d78573db2e9a8cb4","status":"affected","lessThan":"f2e1de075018cf71bcd7d628e9f759cb8540b0c3","versionType":"git"},{"version":"469b390e1ba330e888175e55d78573db2e9a8cb4","status":"affected","lessThan":"383239a33cf29ebee9ce0d4e0e5c900b77a16148","versionType":"git"},{"version":"469b390e1ba330e888175e55d78573db2e9a8cb4","status":"affected","lessThan":"ef1100ef20f29aec4e62abeccdb5bdbebba1e378","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/dsa/microchip/ksz_common.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.7","versionType":"semver"},{"version":"5.10.75","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.14.14","status":"unaffected","lessThanOrEqual":"5.14.*","versionType":"semver"},{"version":"5.15","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/dsa/microchip/ksz_common.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/f2e1de075018cf71bcd7d628e9f759cb8540b0c3"},{"url":"https://git.kernel.org/stable/c/383239a33cf29ebee9ce0d4e0e5c900b77a16148"},{"url":"https://git.kernel.org/stable/c/ef1100ef20f29aec4e62abeccdb5bdbebba1e378"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T13:54:43.614Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.7","versionEndExcluding":"5.10.75"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.7","versionEndExcluding":"5.14.14"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.7","versionEndExcluding":"5.15"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":5.5,"attackVector":"LOCAL","baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","integrityImpact":"NONE","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"LOW","confidentialityImpact":"NONE"}},{"other":{"type":"ssvc","content":{"timestamp":"2024-05-29T18:42:32.231853Z","id":"CVE-2021-47439","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"problemTypes":[{"descriptions":[{"type":"CWE","lang":"en","description":"CWE-noinfo Not enough information"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-10-31T18:04:47.594Z"}},{"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/f2e1de075018cf71bcd7d628e9f759cb8540b0c3","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/383239a33cf29ebee9ce0d4e0e5c900b77a16148","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/ef1100ef20f29aec4e62abeccdb5bdbebba1e378","tags":["x_transferred"]}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2024-08-04T05:39:59.767Z"}}]}}}