{"dataType":"CVE_RECORD","dataVersion":"5.1","cveMetadata":{"cveId":"CVE-2021-47375","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2024-05-21T14:58:30.811Z","datePublished":"2024-05-21T15:03:39.090Z","dateUpdated":"2025-05-04T07:09:38.500Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2025-05-04T07:09:38.500Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nblktrace: Fix uaf in blk_trace access after removing by sysfs\n\nThere is an use-after-free problem triggered by following process:\n\n      P1(sda)\t\t\t\tP2(sdb)\n\t\t\techo 0 > /sys/block/sdb/trace/enable\n\t\t\t  blk_trace_remove_queue\n\t\t\t    synchronize_rcu\n\t\t\t    blk_trace_free\n\t\t\t      relay_close\nrcu_read_lock\n__blk_add_trace\n  trace_note_tsk\n  (Iterate running_trace_list)\n\t\t\t        relay_close_buf\n\t\t\t\t  relay_destroy_buf\n\t\t\t\t    kfree(buf)\n    trace_note(sdb's bt)\n      relay_reserve\n        buf->offset <- nullptr deference (use-after-free) !!!\nrcu_read_unlock\n\n[  502.714379] BUG: kernel NULL pointer dereference, address:\n0000000000000010\n[  502.715260] #PF: supervisor read access in kernel mode\n[  502.715903] #PF: error_code(0x0000) - not-present page\n[  502.716546] PGD 103984067 P4D 103984067 PUD 17592b067 PMD 0\n[  502.717252] Oops: 0000 [#1] SMP\n[  502.720308] RIP: 0010:trace_note.isra.0+0x86/0x360\n[  502.732872] Call Trace:\n[  502.733193]  __blk_add_trace.cold+0x137/0x1a3\n[  502.733734]  blk_add_trace_rq+0x7b/0xd0\n[  502.734207]  blk_add_trace_rq_issue+0x54/0xa0\n[  502.734755]  blk_mq_start_request+0xde/0x1b0\n[  502.735287]  scsi_queue_rq+0x528/0x1140\n...\n[  502.742704]  sg_new_write.isra.0+0x16e/0x3e0\n[  502.747501]  sg_ioctl+0x466/0x1100\n\nReproduce method:\n  ioctl(/dev/sda, BLKTRACESETUP, blk_user_trace_setup[buf_size=127])\n  ioctl(/dev/sda, BLKTRACESTART)\n  ioctl(/dev/sdb, BLKTRACESETUP, blk_user_trace_setup[buf_size=127])\n  ioctl(/dev/sdb, BLKTRACESTART)\n\n  echo 0 > /sys/block/sdb/trace/enable &\n  // Add delay(mdelay/msleep) before kernel enters blk_trace_free()\n\n  ioctl$SG_IO(/dev/sda, SG_IO, ...)\n  // Enters trace_note_tsk() after blk_trace_free() returned\n  // Use mdelay in rcu region rather than msleep(which may schedule out)\n\nRemove blk_trace from running_list before calling blk_trace_free() by\nsysfs if blk_trace is at Blktrace_running state."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/trace/blktrace.c"],"versions":[{"version":"c71a896154119f4ca9e89d6078f5f63ad60ef199","lessThan":"488da313edf3abea7f7733efe011c96b23740ab5","status":"affected","versionType":"git"},{"version":"c71a896154119f4ca9e89d6078f5f63ad60ef199","lessThan":"dacfd5e4d1142bfb3809aab3634a375f6f373269","status":"affected","versionType":"git"},{"version":"c71a896154119f4ca9e89d6078f5f63ad60ef199","lessThan":"d56171d9360c0170c5c5f8f7e2362a2e999eca40","status":"affected","versionType":"git"},{"version":"c71a896154119f4ca9e89d6078f5f63ad60ef199","lessThan":"677e362ba807f3aafe6f405c07e0b37244da5222","status":"affected","versionType":"git"},{"version":"c71a896154119f4ca9e89d6078f5f63ad60ef199","lessThan":"ebb8d26d93c3ec3c7576c52a8373a2309423c069","status":"affected","versionType":"git"},{"version":"c71a896154119f4ca9e89d6078f5f63ad60ef199","lessThan":"3815fe7371d2411ce164281cef40d9fc7b323dee","status":"affected","versionType":"git"},{"version":"c71a896154119f4ca9e89d6078f5f63ad60ef199","lessThan":"a5f8e86192612d0183047448d8bbe7918b3f1a26","status":"affected","versionType":"git"},{"version":"c71a896154119f4ca9e89d6078f5f63ad60ef199","lessThan":"5afedf670caf30a2b5a52da96eb7eac7dee6a9c9","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/trace/blktrace.c"],"versions":[{"version":"2.6.30","status":"affected"},{"version":"0","lessThan":"2.6.30","status":"unaffected","versionType":"semver"},{"version":"4.4.286","lessThanOrEqual":"4.4.*","status":"unaffected","versionType":"semver"},{"version":"4.9.285","lessThanOrEqual":"4.9.*","status":"unaffected","versionType":"semver"},{"version":"4.14.249","lessThanOrEqual":"4.14.*","status":"unaffected","versionType":"semver"},{"version":"4.19.209","lessThanOrEqual":"4.19.*","status":"unaffected","versionType":"semver"},{"version":"5.4.150","lessThanOrEqual":"5.4.*","status":"unaffected","versionType":"semver"},{"version":"5.10.70","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.14.9","lessThanOrEqual":"5.14.*","status":"unaffected","versionType":"semver"},{"version":"5.15","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":"2.6.30","versionEndExcluding":"4.4.286"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"4.9.285"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"4.14.249"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"4.19.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"5.4.150"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"5.10.70"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"5.14.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"5.15"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/488da313edf3abea7f7733efe011c96b23740ab5"},{"url":"https://git.kernel.org/stable/c/dacfd5e4d1142bfb3809aab3634a375f6f373269"},{"url":"https://git.kernel.org/stable/c/d56171d9360c0170c5c5f8f7e2362a2e999eca40"},{"url":"https://git.kernel.org/stable/c/677e362ba807f3aafe6f405c07e0b37244da5222"},{"url":"https://git.kernel.org/stable/c/ebb8d26d93c3ec3c7576c52a8373a2309423c069"},{"url":"https://git.kernel.org/stable/c/3815fe7371d2411ce164281cef40d9fc7b323dee"},{"url":"https://git.kernel.org/stable/c/a5f8e86192612d0183047448d8bbe7918b3f1a26"},{"url":"https://git.kernel.org/stable/c/5afedf670caf30a2b5a52da96eb7eac7dee6a9c9"}],"title":"blktrace: Fix uaf in blk_trace access after removing by sysfs","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"problemTypes":[{"descriptions":[{"type":"CWE","cweId":"CWE-416","lang":"en","description":"CWE-416 Use After Free"}]}],"metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":6.2,"attackVector":"LOCAL","baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","integrityImpact":"NONE","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"NONE","privilegesRequired":"NONE","confidentialityImpact":"HIGH"}},{"other":{"type":"ssvc","content":{"timestamp":"2024-06-17T17:37:23.607827Z","id":"CVE-2021-47375","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2024-10-27T13:59:18.148Z"}},{"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2024-08-04T05:32:08.654Z"},"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/488da313edf3abea7f7733efe011c96b23740ab5","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/dacfd5e4d1142bfb3809aab3634a375f6f373269","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/d56171d9360c0170c5c5f8f7e2362a2e999eca40","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/677e362ba807f3aafe6f405c07e0b37244da5222","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/ebb8d26d93c3ec3c7576c52a8373a2309423c069","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/3815fe7371d2411ce164281cef40d9fc7b323dee","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/a5f8e86192612d0183047448d8bbe7918b3f1a26","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/5afedf670caf30a2b5a52da96eb7eac7dee6a9c9","tags":["x_transferred"]}]}]}}