{"id":"CVE-2026-98839","revision":"fbd7df0608ff400cbdb5da11540af1a6","records":[{"revision":"fbd7df0608ff400cbdb5da11540af1a6","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-98839","aliases":[],"title":"vt: selection: Fix unsigned underflow and slab-out-of-bounds read in paste_selection()","description":"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 - 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 \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 \n ==================================================================","state":0,"publishedAt":"2026-10-18T15:50:11.869+00:00","modifiedAt":"2026-10-19T09:26:31.558+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/tty/vt/selection.c\"\n ],\n \"versions\": [\n {\n \"version\": \"e8c75a30a23c6ba63f4ef6895cbf41fd42f21aa2\",\n \"lessThan\": \"037d7e3ca5c593092f4b0d471eb869a85cbddde0\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"e8c75a30a23c6ba63f4ef6895cbf41fd42f21aa2\",\n \"lessThan\": \"619c6d7dd76fff15a9714fbf02ce299b737f01a2\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"e8c75a30a23c6ba63f4ef6895cbf41fd42f21aa2\",\n \"lessThan\": \"39495ef5d6f8019e62d65807f217a7ca8232727a\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"54c522782fd11a720f959ee9cb5a15bb9580343d\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"05c508edc9d0b44e4706d3c2cf14ee12aac210d2\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"e5be0e24ffc7f5783a3864b5b958088ed15be9e8\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"a4719f6d07b2c63223f7452c435c5f578f105cfe\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"b4492f1e7456bd162714c0ec2815c2749d930844\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"9a9c13ad21a8220cb70c9807a920f43520515f94\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"8c368d36878e2fc99285279fc5e14b3d3cb8947c\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"3.16.83\",\n \"lessThan\": \"3.17\",\n \"status\": \"affected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"4.4.216\",\n \"lessThan\": \"4.5\",\n \"status\": \"affected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"4.9.216\",\n \"lessThan\": \"4.10\",\n \"status\": \"affected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"4.14.173\",\n \"lessThan\": \"4.15\",\n \"status\": \"affected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"4.19.109\",\n \"lessThan\": \"4.20\",\n \"status\": \"affected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.4.25\",\n \"lessThan\": \"5.5\",\n \"status\": \"affected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.5.9\",\n \"lessThan\": \"5.6\",\n \"status\": \"affected\",\n \"versionType\": \"semver\"\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/tty/vt/selection.c\"\n ],\n \"versions\": [\n {\n \"version\": \"5.6\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"5.6\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.18.56\",\n \"lessThanOrEqual\": \"6.18.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.2.10\",\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/037d7e3ca5c593092f4b0d471eb869a85cbddde0","https://git.kernel.org/stable/c/619c6d7dd76fff15a9714fbf02ce299b737f01a2","https://git.kernel.org/stable/c/39495ef5d6f8019e62d65807f217a7ca8232727a"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98839","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-98839","identifiers":["CVE-2026-98839"]},"retained":false,"historicalAffected":[]}],"coverage":[]}