{"id":"CVE-2026-98839","title":"vt: selection: Fix unsigned underflow and slab-out-of-bounds read in paste_selection()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nvt: selection: Fix unsigned underflow and slab-out-of-bounds read in paste_selection()\n\nIn paste_selection(), the loop copies min_t(unsigned int,\nvc_sel.buf_len - paste…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= e8c75a30a23c6ba63f4ef6895cbf41fd42f21aa2 < 037d7e3ca5c593092f4b0d471eb869a85cbddde0","Linux >= e8c75a30a23c6ba63f4ef6895cbf41fd42f21aa2 < 619c6d7dd76fff15a9714fbf02ce299b737f01a2","Linux >= e8c75a30a23c6ba63f4ef6895cbf41fd42f21aa2 < 39495ef5d6f8019e62d65807f217a7ca8232727a","Linux 54c522782fd11a720f959ee9cb5a15bb9580343d","Linux 05c508edc9d0b44e4706d3c2cf14ee12aac210d2","Linux e5be0e24ffc7f5783a3864b5b958088ed15be9e8","Linux a4719f6d07b2c63223f7452c435c5f578f105cfe","Linux b4492f1e7456bd162714c0ec2815c2749d930844","Linux 9a9c13ad21a8220cb70c9807a920f43520515f94","Linux 8c368d36878e2fc99285279fc5e14b3d3cb8947c","Linux >= 3.16.83 < 3.17","Linux >= 4.4.216 < 4.5","Linux >= 4.9.216 < 4.10","Linux >= 4.14.173 < 4.15","Linux >= 4.19.109 < 4.20","Linux >= 5.4.25 < 5.5","Linux >= 5.5.9 < 5.6","Linux 5.6"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:50:11.869Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98839","references":[{"url":"https://git.kernel.org/stable/c/037d7e3ca5c593092f4b0d471eb869a85cbddde0"},{"url":"https://git.kernel.org/stable/c/619c6d7dd76fff15a9714fbf02ce299b737f01a2"},{"url":"https://git.kernel.org/stable/c/39495ef5d6f8019e62d65807f217a7ca8232727a"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T16:47:32.467Z","slug":"CVE-2026-98839","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nvt: selection: Fix unsigned underflow and slab-out-of-bounds read in paste_selection()\n\nIn paste_selection(), the loop copies min_t(unsigned int,\nvc_sel.buf_len - pasted,tty->receive_room) bytes per iteration into\ntty_ldisc_receive_buf() and increments pasted += count.\n\nBecause the selection mutex (vc_sel.lock) is dropped inside the loop\nWhenever the line discipline buffer fills up and paste_selection()\nsleeps on tty->write_wait, a concurrent TIOCLINUX (TIOCL_SETSEL) ioctl\ncan replace vc_sel.buffer with a shorter selection and reduce\nvc_sel.buf_len below pasted.\n\nWhen paste_selection() resumes, vc_sel.buf_len - pasted underflows as an\nunsigned integer to a large positive value, causing\ntty_ldisc_receive_buf(ld, vc_sel.buffer + pasted, NULL, count) to read\nup to 4094 bytes out-of-bounds past the newly allocated vc_sel.buffer.\n\nFix this by terminating the loop when pasted >= vc_sel.buf_len.\n\nKernel stack trace (Linux 7.3.0-rc3):\n ==================================================================\n BUG: KASAN: slab-out-of-bounds in n_tty_receive_buf_common+0xa01/0x1650\n Read of size 4094 at addr ffff888101c58010 by task kworker/u17:1/65\n Workqueue: events_unbound flush_to_ldisc\n Call Trace:\n  <TASK>\n  dump_stack_lvl+0x70/0xa0\n  print_report+0x153/0x4c6\n  kasan_report+0xf1/0x120\n  kasan_check_range+0x11c/0x200\n  __asan_memcpy+0x29/0x70\n  n_tty_receive_buf_common+0xa01/0x1650\n  tty_ldisc_receive_buf+0x66/0x110\n  tty_port_default_receive_buf+0x6b/0xb0\n  flush_to_ldisc+0x1b4/0x410\n  process_one_work+0x6ff/0x1110\n  worker_thread+0x4a8/0xb70\n  kthread+0x307/0x3e0\n  ret_from_fork+0x3ed/0x680\n  </TASK>\n ==================================================================\n\n## Affected\n\n- `Linux >= e8c75a30a23c6ba63f4ef6895cbf41fd42f21aa2 < 037d7e3ca5c593092f4b0d471eb869a85cbddde0`\n- `Linux >= e8c75a30a23c6ba63f4ef6895cbf41fd42f21aa2 < 619c6d7dd76fff15a9714fbf02ce299b737f01a2`\n- `Linux >= e8c75a30a23c6ba63f4ef6895cbf41fd42f21aa2 < 39495ef5d6f8019e62d65807f217a7ca8232727a`\n- `Linux 54c522782fd11a720f959ee9cb5a15bb9580343d`\n- `Linux 05c508edc9d0b44e4706d3c2cf14ee12aac210d2`\n- `Linux e5be0e24ffc7f5783a3864b5b958088ed15be9e8`\n- `Linux a4719f6d07b2c63223f7452c435c5f578f105cfe`\n- `Linux b4492f1e7456bd162714c0ec2815c2749d930844`\n- `Linux 9a9c13ad21a8220cb70c9807a920f43520515f94`\n- `Linux 8c368d36878e2fc99285279fc5e14b3d3cb8947c`\n- `Linux >= 3.16.83 < 3.17`\n- `Linux >= 4.4.216 < 4.5`\n- `Linux >= 4.9.216 < 4.10`\n- `Linux >= 4.14.173 < 4.15`\n- `Linux >= 4.19.109 < 4.20`\n- `Linux >= 5.4.25 < 5.5`\n- `Linux >= 5.5.9 < 5.6`\n- `Linux 5.6`\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":[]}