{"id":"CVE-2022-50394","state":"PUBLISHED","title":"i2c: ismt: Fix an out-of-bounds bug in ismt_access()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ni2c: ismt: Fix an out-of-bounds bug in ismt_access()\n\nWhen the driver does not check the data from the user, the variable\n'data->block[0]' may be very large to cause an out-of-bounds bug.\n\nThe following log can reveal it:\n\n[   33.995542] i2c i2c-1: ioctl, cmd=0x720, arg=0x7ffcb3dc3a20\n[   33.995978] ismt_smbus 0000:00:05.0: I2C_SMBUS_BLOCK_DATA:  WRITE\n[   33.996475] ==================================================================\n[   33.996995] BUG: KASAN: out-of-bounds in ismt_access.cold+0x374/0x214b\n[   33.997473] Read of size 18446744073709551615 at addr ffff88810efcfdb1 by task ismt_poc/485\n[   33.999450] Call Trace:\n[   34.001849]  memcpy+0x20/0x60\n[   34.002077]  ismt_access.cold+0x374/0x214b\n[   34.003382]  __i2c_smbus_xfer+0x44f/0xfb0\n[   34.004007]  i2c_smbus_xfer+0x10a/0x390\n[   34.004291]  i2cdev_ioctl_smbus+0x2c8/0x710\n[   34.005196]  i2cdev_ioctl+0x5ec/0x74c\n\nFix this bug by checking the size of 'data->block[0]' first.","publishedAt":"2025-09-18T13:33:12.992Z","updatedAt":"2026-08-05T08:58:32.577Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9","status":"affected","lessThan":"4a7bb1d93addb2f67e36fed00a53cb7f270d7b7a","versionType":"git"},{"version":"13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9","status":"affected","lessThan":"03b7ef7a6c5ca1ff553470166b4919db88b810f6","versionType":"git"},{"version":"13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9","status":"affected","lessThan":"bfe41d966c860a8ad4c735639d616da270c92735","versionType":"git"},{"version":"13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9","status":"affected","lessThan":"cdcbae2c5003747ddfd14e29db9c1d5d7e7c44dd","versionType":"git"},{"version":"13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9","status":"affected","lessThan":"9ac541a0898e8ec187a3fa7024b9701cffae6bf2","versionType":"git"},{"version":"13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9","status":"affected","lessThan":"96c12fd0ec74641295e1c3c34dea3dce1b6c3422","versionType":"git"},{"version":"13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9","status":"affected","lessThan":"a642469d464b2780a25a49b51ae56623c65eac34","versionType":"git"},{"version":"13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9","status":"affected","lessThan":"233348a04becf133283f0076e20b317302de21d9","versionType":"git"},{"version":"13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9","status":"affected","lessThan":"39244cc754829bf707dccd12e2ce37510f5b1f8d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/i2c/busses/i2c-ismt.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.9","versionType":"semver"},{"version":"4.9.337","status":"unaffected","lessThanOrEqual":"4.9.*","versionType":"semver"},{"version":"4.14.303","status":"unaffected","lessThanOrEqual":"4.14.*","versionType":"semver"},{"version":"4.19.270","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.229","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.163","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.86","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.0.16","status":"unaffected","lessThanOrEqual":"6.0.*","versionType":"semver"},{"version":"6.1.2","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/i2c/busses/i2c-ismt.c"]}],"references":["https://git.kernel.org/stable/c/4a7bb1d93addb2f67e36fed00a53cb7f270d7b7a","https://git.kernel.org/stable/c/03b7ef7a6c5ca1ff553470166b4919db88b810f6","https://git.kernel.org/stable/c/bfe41d966c860a8ad4c735639d616da270c92735","https://git.kernel.org/stable/c/cdcbae2c5003747ddfd14e29db9c1d5d7e7c44dd","https://git.kernel.org/stable/c/9ac541a0898e8ec187a3fa7024b9701cffae6bf2","https://git.kernel.org/stable/c/96c12fd0ec74641295e1c3c34dea3dce1b6c3422","https://git.kernel.org/stable/c/a642469d464b2780a25a49b51ae56623c65eac34","https://git.kernel.org/stable/c/233348a04becf133283f0076e20b317302de21d9","https://git.kernel.org/stable/c/39244cc754829bf707dccd12e2ce37510f5b1f8d"],"weaknesses":["CWE-125"],"ingestedAt":"2026-10-29T20:05:26.763Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2022/50xxx/CVE-2022-50394.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2022-50394","state":"PUBLISHED","datePublished":"2025-09-18T13:33:12.992Z","dateUpdated":"2026-08-05T08:58:32.577Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-09-17T14:53:06.998Z"},"containers":{"cna":{"title":"i2c: ismt: Fix an out-of-bounds bug in ismt_access()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ni2c: ismt: Fix an out-of-bounds bug in ismt_access()\n\nWhen the driver does not check the data from the user, the variable\n'data->block[0]' may be very large to cause an out-of-bounds bug.\n\nThe following log can reveal it:\n\n[   33.995542] i2c i2c-1: ioctl, cmd=0x720, arg=0x7ffcb3dc3a20\n[   33.995978] ismt_smbus 0000:00:05.0: I2C_SMBUS_BLOCK_DATA:  WRITE\n[   33.996475] ==================================================================\n[   33.996995] BUG: KASAN: out-of-bounds in ismt_access.cold+0x374/0x214b\n[   33.997473] Read of size 18446744073709551615 at addr ffff88810efcfdb1 by task ismt_poc/485\n[   33.999450] Call Trace:\n[   34.001849]  memcpy+0x20/0x60\n[   34.002077]  ismt_access.cold+0x374/0x214b\n[   34.003382]  __i2c_smbus_xfer+0x44f/0xfb0\n[   34.004007]  i2c_smbus_xfer+0x10a/0x390\n[   34.004291]  i2cdev_ioctl_smbus+0x2c8/0x710\n[   34.005196]  i2cdev_ioctl+0x5ec/0x74c\n\nFix this bug by checking the size of 'data->block[0]' first."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9","status":"affected","lessThan":"4a7bb1d93addb2f67e36fed00a53cb7f270d7b7a","versionType":"git"},{"version":"13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9","status":"affected","lessThan":"03b7ef7a6c5ca1ff553470166b4919db88b810f6","versionType":"git"},{"version":"13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9","status":"affected","lessThan":"bfe41d966c860a8ad4c735639d616da270c92735","versionType":"git"},{"version":"13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9","status":"affected","lessThan":"cdcbae2c5003747ddfd14e29db9c1d5d7e7c44dd","versionType":"git"},{"version":"13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9","status":"affected","lessThan":"9ac541a0898e8ec187a3fa7024b9701cffae6bf2","versionType":"git"},{"version":"13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9","status":"affected","lessThan":"96c12fd0ec74641295e1c3c34dea3dce1b6c3422","versionType":"git"},{"version":"13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9","status":"affected","lessThan":"a642469d464b2780a25a49b51ae56623c65eac34","versionType":"git"},{"version":"13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9","status":"affected","lessThan":"233348a04becf133283f0076e20b317302de21d9","versionType":"git"},{"version":"13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9","status":"affected","lessThan":"39244cc754829bf707dccd12e2ce37510f5b1f8d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/i2c/busses/i2c-ismt.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.9","versionType":"semver"},{"version":"4.9.337","status":"unaffected","lessThanOrEqual":"4.9.*","versionType":"semver"},{"version":"4.14.303","status":"unaffected","lessThanOrEqual":"4.14.*","versionType":"semver"},{"version":"4.19.270","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.229","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.163","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.86","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.0.16","status":"unaffected","lessThanOrEqual":"6.0.*","versionType":"semver"},{"version":"6.1.2","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/i2c/busses/i2c-ismt.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/4a7bb1d93addb2f67e36fed00a53cb7f270d7b7a"},{"url":"https://git.kernel.org/stable/c/03b7ef7a6c5ca1ff553470166b4919db88b810f6"},{"url":"https://git.kernel.org/stable/c/bfe41d966c860a8ad4c735639d616da270c92735"},{"url":"https://git.kernel.org/stable/c/cdcbae2c5003747ddfd14e29db9c1d5d7e7c44dd"},{"url":"https://git.kernel.org/stable/c/9ac541a0898e8ec187a3fa7024b9701cffae6bf2"},{"url":"https://git.kernel.org/stable/c/96c12fd0ec74641295e1c3c34dea3dce1b6c3422"},{"url":"https://git.kernel.org/stable/c/a642469d464b2780a25a49b51ae56623c65eac34"},{"url":"https://git.kernel.org/stable/c/233348a04becf133283f0076e20b317302de21d9"},{"url":"https://git.kernel.org/stable/c/39244cc754829bf707dccd12e2ce37510f5b1f8d"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - Reachable only via local I2C_SMBUS ioctl on /dev/i2c-* (i2cdev_ioctl → i2cdev_ioctl_smbus → i2c_smbus_xfer → ismt_access); not network- or physically-triggered.\nAC:L - Attacker fully controls block[0] in the ioctl payload and can reliably trigger the OOB memcpy (including the u8 wrap to SIZE_MAX when block[0]==255); no race or external conditions required.\nPR:L - No capability check in i2cdev_open; access is only gated by /dev/i2c-* permissions, which commonly allow non-root users (e.g. i2c group). Matches sibling i2c block-length scores such as CVE-2026-64191.\nUI:N - Exploitation requires only the attacker's own open/ioctl sequence; no victim action is needed.\nS:U - Impact is confined to the host kernel privilege boundary (memory corruption / DoS); no VM escape or cross-authority boundary crossing.\nC:H - memcpy performs an unbounded/out-of-bounds read from union i2c_smbus_data past the 34-byte block buffer, disclosing adjacent kernel memory; oversized DMA mapping can further expose kernel data.\nI:H - The same memcpy writes past priv->buffer into adjacent ismt_priv fields (e.g. log_dma/log), giving a heap structure corruption / write primitive; out-of-bounds write is High per guidance.\nA:H - The OOB access causes a kernel oops/KASAN crash (as in the reported PoC), enabling reliable denial of service."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T08:58:32.577Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"4.9.337"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"4.14.303"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"4.19.270"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"5.4.229"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"5.10.163"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"5.15.86"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"6.0.16"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"6.1.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"6.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":7.1,"attackVector":"LOCAL","baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","integrityImpact":"NONE","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"LOW","confidentialityImpact":"HIGH"}},{"other":{"type":"ssvc","content":{"id":"CVE-2022-50394","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-01-14T18:51:21.854586Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-125","lang":"en","type":"CWE","description":"CWE-125 Out-of-bounds Read"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-01-14T18:53:05.857Z"}}]}}}