{"id":"CVE-2026-90055","title":"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:382:3…","summary":"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:382:3…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= c59bba75fa500f13ef14215d599ee0d7faa1b954 < 8442586526c406527bf31206e538c0ce6bc672e6","Linux >= c59bba75fa500f13ef14215d599ee0d7faa1b954 < 561cbd6d49022c9a383e22a39c87a165a4d39f9c","Linux >= c59bba75fa500f13ef14215d599ee0d7faa1b954 < 76bc7c3a44856744b64aa91d9afe6d9522a78c42","Linux >= c59bba75fa500f13ef14215d599ee0d7faa1b954 < 7baa0c92be39eb3da755ed6f200497a57078c47b","Linux >= c59bba75fa500f13ef14215d599ee0d7faa1b954 < 1e964d414bfd9f8dfe9948d08e4b9dda4ed2e422","Linux >= c59bba75fa500f13ef14215d599ee0d7faa1b954 < ff7f77a234f7b74e5955a6e34fa74eca4c9ca44c","Linux >= c59bba75fa500f13ef14215d599ee0d7faa1b954 < 75667703115154a4fd9cf259d4f826d8729cbcda","Linux >= c59bba75fa500f13ef14215d599ee0d7faa1b954 < a60fd8c6dbaa76da4163cf225ed2b9e982540f39","Linux 2.6.13"],"published":"2026-09-17","updated":"2026-09-17","sourceUpdated":"2026-09-17T17:16:54.020","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-90055","references":[{"url":"https://git.kernel.org/stable/c/1e964d414bfd9f8dfe9948d08e4b9dda4ed2e422","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/561cbd6d49022c9a383e22a39c87a165a4d39f9c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/75667703115154a4fd9cf259d4f826d8729cbcda","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/76bc7c3a44856744b64aa91d9afe6d9522a78c42","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7baa0c92be39eb3da755ed6f200497a57078c47b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8442586526c406527bf31206e538c0ce6bc672e6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a60fd8c6dbaa76da4163cf225ed2b9e982540f39","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ff7f77a234f7b74e5955a6e34fa74eca4c9ca44c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-17T16:21:47.903Z","epss":0.00211,"epssPercentile":0.11593,"slug":"CVE-2026-90055","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}