{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2022-48760", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2022-48760", "idYear": 2022, "status": "PUBLISHED", "publishedAt": "2024-06-20T11:13:38.532Z", "updatedAt": "2026-05-11T18:46:24.191Z", "importedAt": "2026-10-24T01:56:45.230Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "USB: core: Fix hang in usb_kill_urb by adding memory barriers", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nUSB: core: Fix hang in usb_kill_urb by adding memory barriers\n\nThe syzbot fuzzer has identified a bug in which processes hang waiting\nfor usb_kill_urb() to return. It turns out the issue is not unlinking\nthe URB; that works just fine. Rather, the problem arises when the\nwakeup notification that the URB has completed is not received.\n\nThe reason is memory-access ordering on SMP systems. In outline form,\nusb_kill_urb() and __usb_hcd_giveback_urb() operating concurrently on\ndifferent CPUs perform the following actions:\n\nCPU 0\t\t\t\t\tCPU 1\n----------------------------\t\t---------------------------------\nusb_kill_urb():\t\t\t\t__usb_hcd_giveback_urb():\n ...\t\t\t\t\t ...\n atomic_inc(&urb->reject);\t\t atomic_dec(&urb->use_count);\n ...\t\t\t\t\t ...\n wait_event(usb_kill_urb_queue,\n\tatomic_read(&urb->use_count) == 0);\n\t\t\t\t\t if (atomic_read(&urb->reject))\n\t\t\t\t\t\twake_up(&usb_kill_urb_queue);\n\nConfining your attention to urb->reject and urb->use_count, you can\nsee that the overall pattern of accesses on CPU 0 is:\n\n\twrite urb->reject, then read urb->use_count;\n\nwhereas the overall pattern of accesses on CPU 1 is:\n\n\twrite urb->use_count, then read urb->reject.\n\nThis pattern is referred to in memory-model circles as SB (for \"Store\nBuffering\"), and it is well known that without suitable enforcement of\nthe desired order of accesses -- in the form of memory barriers -- it\nis entirely possible for one or both CPUs to execute their reads ahead\nof their writes. The end result will be that sometimes CPU 0 sees the\nold un-decremented value of urb->use_count while CPU 1 sees the old\nun-incremented value of urb->reject. Consequently CPU 0 ends up on\nthe wait queue and never gets woken up, leading to the observed hang\nin usb_kill_urb().\n\nThe same pattern of accesses occurs in usb_poison_urb() and the\nfailure pathway of usb_hcd_submit_urb().\n\nThe problem is fixed by adding suitable memory barriers. To provide\nproper memory-access ordering in the SB pattern, a full barrier is\nrequired on both CPUs. The atomic_inc() and atomic_dec() accesses\nthemselves don't provide any memory ordering, but since they are\npresent, we can use the optimized smp_mb__after_atomic() memory\nbarrier in the various routines to obtain the desired effect.\n\nThis patch adds the necessary memory barriers.", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "49367d8f1d9f26482cf7089489e90f0afd0a942c", "status": "affected", "versionType": "git", "lessThan": "5f138ef224dffd15d5e5c5b095859719e0038427" }, { "version": "49367d8f1d9f26482cf7089489e90f0afd0a942c", "status": "affected", "versionType": "git", "lessThan": "b50f5ca60475710bbc9a3af32fbfc17b1e69c2f0" }, { "version": "49367d8f1d9f26482cf7089489e90f0afd0a942c", "status": "affected", "versionType": "git", "lessThan": "546ba238535d925254e0b3f12012a5c55801e2f3" }, { "version": "49367d8f1d9f26482cf7089489e90f0afd0a942c", "status": "affected", "versionType": "git", "lessThan": "5904dfd3ddaff3bf4a41c3baf0a8e8f31ed4599b" }, { "version": "49367d8f1d9f26482cf7089489e90f0afd0a942c", "status": "affected", "versionType": "git", "lessThan": "9c61fce322ac2ef7fecf025285353570d60e41d6" }, { "version": "49367d8f1d9f26482cf7089489e90f0afd0a942c", "status": "affected", "versionType": "git", "lessThan": "e3b131e30e612ff0e32de6c1cb4f69f89db29193" }, { "version": "49367d8f1d9f26482cf7089489e90f0afd0a942c", "status": "affected", "versionType": "git", "lessThan": "9340226388c66a7e090ebb00e91ed64a753b6c26" }, { "version": "49367d8f1d9f26482cf7089489e90f0afd0a942c", "status": "affected", "versionType": "git", "lessThan": "c9a18f7c5b071dce5e6939568829d40994866ab0" }, { "version": "49367d8f1d9f26482cf7089489e90f0afd0a942c", "status": "affected", "versionType": "git", "lessThan": "26fbe9772b8c459687930511444ce443011f86bf" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "2.6.29", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "2.6.29" }, { "version": "4.4.302", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "4.4.*" }, { "version": "4.9.300", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "4.9.*" }, { "version": "4.14.265", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "4.14.*" }, { "version": "4.19.228", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "4.19.*" }, { "version": "5.4.176", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.4.*" }, { "version": "5.10.96", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.10.*" }, { "version": "5.15.19", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.15.*" }, { "version": "5.16.5", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.16.*" }, { "version": "5.17", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }