vt: selection: Fix unsigned underflow and slab-out-of-bounds read in paste_selection()
In the Linux kernel, the following vulnerability has been resolved: vt: selection: Fix unsigned underflow and slab-out-of-bounds read in paste_selection() In paste_selection(), the loop copies min_t(unsigned int, vc_sel.buf_len - pasted,tty->receive_room) bytes per iteration into tty_ldisc_receive_buf() and increments pasted += count. Because the selection mutex (vc_sel.lock) is dropped inside the loop Whenever the line discipline buffer fills up and paste_selection() sleeps on tty->write_wait, a concurrent TIOCLINUX (TIOCL_SETSEL) ioctl can replace vc_sel.buffer with a shorter selection and reduce vc_sel.buf_len below pasted. When paste_selection() resumes, vc_sel.buf_len - pasted underflows as an unsigned integer to a large positive value, causing tty_ldisc_receive_buf(ld, vc_sel.buffer + pasted, NULL, count) to read up to 4094 bytes out-of-bounds past the newly allocated vc_sel.buffer. Fix this by terminating the loop when pasted >= vc_sel.buf_len. Kernel stack trace (Linux 7.3.0-rc3): ================================================================== BUG: KASAN: slab-out-of-bounds in n_tty_receive_buf_common+0xa01/0x1650 Read of size 4094 at addr ffff888101c58010 by task kworker/u17:1/65 Workqueue: events_unbound flush_to_ldisc Call Trace: dump_stack_lvl+0x70/0xa0 print_report+0x153/0x4c6 kasan_report+0xf1/0x120 kasan_check_range+0x11c/0x200 __asan_memcpy+0x29/0x70 n_tty_receive_buf_common+0xa01/0x1650 tty_ldisc_receive_buf+0x66/0x110 tty_port_default_receive_buf+0x6b/0xb
CVE-2026-98839
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-98839
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "e8c75a30a23c6ba63f4ef6895cbf41fd42f21aa2",
"lessThan": "037d7e3ca5c593092f4b0d471eb869a85cbddde0",
"versionType": "git"
},
{
"status": "affected",
"version": "e8c75a30a23c6ba63f4ef6895cbf41fd42f21aa2",
"lessThan": "619c6d7dd76fff15a9714fbf02ce299b737f01a2",
"versionType": "git"
},
{
"status": "affected",
"version": "e8c75a30a23c6ba63f4ef6895cbf41fd42f21aa2",
"lessThan": "39495ef5d6f8019e62d65807f217a7ca8232727a",
"versionType": "git"
},
{
"status": "affected",
"version": "54c522782fd11a720f959ee9cb5a15bb9580343d",
"versionType": "git"
},
{
"status": "affected",
"version": "05c508edc9d0b44e4706d3c2cf14ee12aac210d2",
"versionType": "git"
},
{
"status": "affected",
"version": "e5be0e24ffc7f5783a3864b5b958088ed15be9e8",
"versionType": "git"
},
{
"status": "affected",
"version": "a4719f6d07b2c63223f7452c435c5f578f105cfe",
"versionType": "git"
},
{
"status": "affected",
"version": "b4492f1e7456bd162714c0ec2815c2749d930844",
"versionType": "git"
},
{
"status": "affected",
"version": "9a9c13ad21a8220cb70c9807a920f43520515f94",
"versionType": "git"
},
{
"status": "affected",
"version": "8c368d36878e2fc99285279fc5e14b3d3cb8947c",
"versionType": "git"
},
{
"status": "affected",
"version": "3.16.83",
"lessThan": "3.17",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.4.216",
"lessThan": "4.5",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.9.216",
"lessThan": "4.10",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.14.173",
"lessThan": "4.15",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.19.109",
"lessThan": "4.20",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.4.25",
"lessThan": "5.5",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.5.9",
"lessThan": "5.6",
"versionType": "semver"
}
],
"programFiles": [
"drivers/tty/vt/selection.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.6"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.6",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.18.56",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.10",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/tty/vt/selection.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-98839
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #38745 · Revision 1
- Added to Heist Feed
- Publisher date