{"id":"CVE-2026-90055","revision":"4c3652302ea24539a1df21bdd124d3dd","records":[{"revision":"4c3652302ea24539a1df21bdd124d3dd","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-90055","aliases":[],"title":"usb: atm: usbatm: fix invalid ci_range initialization","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: atm: usbatm: fix invalid ci_range initialization\n\nsyzbot reported a shift-out-of-bounds in __vcc_connect():\n\n  UBSAN: shift-out-of-bounds in net/atm/common.c:382:32\n  shift exponent -1 is negative\n  CPU: 0 UID: 0 PID: 5987 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT(full)\n  Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026\n  Call Trace:\n   <TASK>\n   dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120\n   ubsan_epilogue+0xa/0x30 lib/ubsan.c:233\n   __ubsan_handle_shift_out_of_bounds+0x36d/0x400 lib/ubsan.c:494\n   __vcc_connect+0x14b4/0x19c0 net/atm/common.c:382\n   vcc_connect+0x328/0x8f0 net/atm/common.c:498\n   pvc_bind+0x272/0x380 net/atm/pvc.c:52\n   __sys_bind+0x2e3/0x410 net/socket.c:1976\n   __x64_sys_bind+0x7a/0x90 net/socket.c:1979\n   ...\n\nATM device ci_range fields (vpi_bits and vci_bits) represent the\nnumber of bits supported for VPI and VCI addressing on the device.\nnet/atm/common.c directly uses these fields as bit shift counts:\n  vpi >> dev->ci_range.vpi_bits\n  vci >> dev->ci_range.vci_bits\n  1 << vcc->dev->ci_range.vpi_bits\n  1 << vcc->dev->ci_range.vci_bits\n\nusbatm_atm_init() sets ci_range.vpi_bits and ci_range.vci_bits to\nATM_CI_MAX (-1), which is defined in <uapi/linux/atmdev.h> as a\nsentinel value for userspace ATM_SETCIRANGE requests, not a valid bit\ncount. Shifting by -1 is undefined behavior and triggers UBSAN\nwarnings.\n\nATM UNI cell headers allow up to 8 bits for VPI (0..255) and 16 bits\nfor VCI (0..65535). Initialize vpi_bits to 8 and vci_bits to 16, as\ndone by solos-pci.","state":0,"publishedAt":"2026-09-17T16:05:40.304+00:00","modifiedAt":"2026-10-19T08:57:12.606+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"drivers/usb/atm/usbatm.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"c59bba75fa500f13ef14215d599ee0d7faa1b954\",\n                            \"lessThan\": \"8442586526c406527bf31206e538c0ce6bc672e6\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c59bba75fa500f13ef14215d599ee0d7faa1b954\",\n                            \"lessThan\": \"561cbd6d49022c9a383e22a39c87a165a4d39f9c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c59bba75fa500f13ef14215d599ee0d7faa1b954\",\n                            \"lessThan\": \"76bc7c3a44856744b64aa91d9afe6d9522a78c42\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c59bba75fa500f13ef14215d599ee0d7faa1b954\",\n                            \"lessThan\": \"7baa0c92be39eb3da755ed6f200497a57078c47b\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c59bba75fa500f13ef14215d599ee0d7faa1b954\",\n                            \"lessThan\": \"1e964d414bfd9f8dfe9948d08e4b9dda4ed2e422\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c59bba75fa500f13ef14215d599ee0d7faa1b954\",\n                            \"lessThan\": \"ff7f77a234f7b74e5955a6e34fa74eca4c9ca44c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c59bba75fa500f13ef14215d599ee0d7faa1b954\",\n                            \"lessThan\": \"75667703115154a4fd9cf259d4f826d8729cbcda\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c59bba75fa500f13ef14215d599ee0d7faa1b954\",\n                            \"lessThan\": \"a60fd8c6dbaa76da4163cf225ed2b9e982540f39\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"drivers/usb/atm/usbatm.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"2.6.13\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"2.6.13\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.270\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.221\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.188\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.157\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.110\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.52\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.6\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/8442586526c406527bf31206e538c0ce6bc672e6","https://git.kernel.org/stable/c/561cbd6d49022c9a383e22a39c87a165a4d39f9c","https://git.kernel.org/stable/c/76bc7c3a44856744b64aa91d9afe6d9522a78c42","https://git.kernel.org/stable/c/7baa0c92be39eb3da755ed6f200497a57078c47b","https://git.kernel.org/stable/c/1e964d414bfd9f8dfe9948d08e4b9dda4ed2e422","https://git.kernel.org/stable/c/ff7f77a234f7b74e5955a6e34fa74eca4c9ca44c","https://git.kernel.org/stable/c/75667703115154a4fd9cf259d4f826d8729cbcda","https://git.kernel.org/stable/c/a60fd8c6dbaa76da4163cf225ed2b9e982540f39"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-90055","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-90055","identifiers":["CVE-2026-90055"]},"retained":false,"historicalAffected":[]}],"coverage":[]}