{
"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-2026-93287",
"sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-93287",
"idYear": 2026,
"status": "PUBLISHED",
"publishedAt": "2026-09-24T16:02:11.296Z",
"updatedAt": "2026-10-03T10:57:13.466Z",
"importedAt": "2026-10-24T01:58:35.090Z",
"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": "i2c: smbus: reject oversized block transfers in the common path",
"summary": "In the Linux kernel, the following vulnerability has been resolved:\n\ni2c: smbus: reject oversized block transfers in the common path\n\nThe SMBus block transfer length data->block[0] is validated in\ni2c_smbus_xfer_emulated() but that check runs too late for tracepoints\nand is skipped entirely when the adapter provides a native smbus_xfer\nimplementation. This allows user-controlled oversized block lengths to\nreach tracepoint memcpy calls and driver callbacks unchecked.\n\nAdd an early validation in __i2c_smbus_xfer() that rejects block\ntransfers whose caller-supplied length is zero or exceeds\nI2C_SMBUS_BLOCK_MAX before any tracepoint fires or driver callback\nruns. data->block[0] is filled in by the device on SMBus block reads,\nso the check is scoped to operations where the length is actually\nsupplied by the caller. This is consistent with the existing -EINVAL\nconvention in the emulated path and protects all downstream consumers\nat once: the smbus_write tracepoint, all native smbus_xfer driver\nimplementations, and the emulated path.\n\nTwo distinct bugs are fixed by this change:\n\nBug 1: smbus_write tracepoint OOB (include/trace/events/smbus.h)\n trace_smbus_write() fires before any validation and copies\n data->block[0]+1 bytes into a 34-byte event buffer. With\n block[0]=0xfe the tracepoint copies 255 bytes, overflowing by 221.\n\n BUG: KASAN: stack-out-of-bounds in trace_event_raw_event_smbus_write+0x27c/0x530\n Read of size 255 at addr ffff88800d98fcf8 by task poc_smbus/91\n Call Trace:\n \n __asan_memcpy+0x23/0x80\n trace_event_raw_event_smbus_write+0x27c/0x530\n __i2c_smbus_xfer+0x43a/0xa40\n i2c_smbus_xfer+0x19e/0x340\n i2cdev_ioctl_smbus+0x38f/0x7f0\n i2cdev_ioctl+0x35e/0x680\n __x64_sys_ioctl+0x147/0x1e0\n do_syscall_64+0xcf/0x15a0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n \n\nBug 2: i2c-stub I2C_SMBUS_I2C_BLOCK_DATA OOB (drivers/i2c/i2c-stub.c)\n stub_xfer() implements .smbus_xfer directly and only clamps\n block[0] against 256-command, not I2C_SMBUS_BLOCK_MAX. With\n block[0]=0xff and command=0 the loop accesses block[1+i] for\n i up to 254, far past the 34-byte union.\n\n UBSAN: array-index-out-of-bounds in drivers/i2c/i2c-stub.c:223:44\n index 34 is out of range for type '__u8 [34]'\n Call Trace:\n \n __ubsan_handle_out_of_bounds+0xd7/0x120\n stub_xfer+0x1971/0x198f [i2c_stub]\n __i2c_smbus_xfer+0x306/0xa40\n i2c_smbus_xfer+0x19e/0x340\n i2cdev_ioctl_smbus+0x38f/0x7f0\n i2cdev_ioctl+0x35e/0x680\n __x64_sys_ioctl+0x147/0x1e0\n do_syscall_64+0xcf/0x15a0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n \n\nBoth traces reproduced on v7.0-rc6+i2c/for-current with KASAN+UBSAN.",
"affected": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"versions": [
{
"version": "4710317891e4824ce1510a6b5066abbd3e917750",
"status": "affected",
"versionType": "git",
"lessThan": "856dffcc097b3d8ed45a643ebda07cb92968cb33"
},
{
"version": "4710317891e4824ce1510a6b5066abbd3e917750",
"status": "affected",
"versionType": "git",
"lessThan": "356875e33f2c6d2061a02c9dec1a1e639d265a55"
},
{
"version": "4710317891e4824ce1510a6b5066abbd3e917750",
"status": "affected",
"versionType": "git",
"lessThan": "72ca5e0b8b7a62615758f8871c34d61616c2dc8b"
},
{
"version": "4710317891e4824ce1510a6b5066abbd3e917750",
"status": "affected",
"versionType": "git",
"lessThan": "df077253f6405d67ad087538e495ef32a05717b7"
},
{
"version": "4710317891e4824ce1510a6b5066abbd3e917750",
"status": "affected",
"versionType": "git",
"lessThan": "f09edffba97d37b1fdff5f818a9a45f8a98ac171"
},
{
"version": "4710317891e4824ce1510a6b5066abbd3e917750",
"status": "affected",
"versionType": "git",
"lessThan": "c4b478bc50b7ca9865e237909941253a0f7111a2"
},
{
"version": "4710317891e4824ce1510a6b5066abbd3e917750",
"status": "affected",
"versionType": "git",
"lessThan": "3051cd060fa496df42954291fa2306ed2eab4ecc"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"versions": [
{
"version": "2.6.33",
"status": "affected"
},
{
"version": "0",
"status": "unaffected",
"versionType": "semver",
"lessThan": "2.6.33"
},
{
"version": "5.10.271",
"status": "unaffected",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"version": "5.15.222",
"status": "unaffected",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"version": "6.1.189",
"status": "unaffected",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"version": "6.6.158",
"status": "unaffected",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"version": "6.12.111",
"status": "unaffected",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"version": "6.18.53",
"status": "unaffected",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"version": "7.1",
"status": "unaffected",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
]
}
]
}
}
}