CVE-2026-98969
In the Linux kernel, the following vulnerability has been resolved: net/sched: em_text: reject unterminated algo before autoload This is a
CVSS
—
No CVSS
EPSS
—
KEV
—
Exploit Today
—
0-100
Published: Oct 23, 2026 · Last modified: Oct 23, 2026
Not enough EPSS history yet.
In the Linux kernel, the following vulnerability has been resolved: net/sched: em_text: reject unterminated algo before autoload This is a follow-up to commit 9c572a83037a ("net/sched: fix potential stack infoleak in em_text_dump()"), which zero-initialised the dump-side struct. Sashiko pointed at a pre-existing bug that exposed the change-side input-validation gap open. em_text_change() casts the raw netlink attribute payload to struct tcf_em_text and passes conf->algo, a 16-byte array with no enforced NUL terminator, to textsearch_prepare(). On the TS_AUTOLOAD retry textsearch_prepare() calls request_module("ts_%s", algo); vsnprintf() walks %s until it finds a NUL, so an algo[] with no NUL reads past the array into the adjacent struct fields and payload and feeds those bytes to the usermode helper command line. This is an out-of-bounds read and a kernel memory disclosure. Reject the attribute when no NUL exists within TC_EM_TEXT_ALGOSIZ bytes, matching the check xt_string has had since 3ab720881b6e. Conditions to recreate the bug: - CAP_NET_ADMIN on the target netns (namespace-local via unshare -Urn is enough) - install clsact on an interface, then add a basic filter with one text ematch whose algo[] is 16 bytes with no NUL (e.g. "A"*16) and pattern_len at least 1 - the add fails with -ENOENT and the kernel invokes modprobe with a module name made of "ts_" plus the 16 bytes and the adjacent payload
- git.kernel.orghttps://git.kernel.org/stable/c/00bcc303000bac524d62eed054d77372b38ace0f
- git.kernel.orghttps://git.kernel.org/stable/c/22182f91c6703af6e9832cffe6d22b381031cb5a
- git.kernel.orghttps://git.kernel.org/stable/c/85e5512369d4fe6e5f2c43712d9f9e01d4ae8437
- git.kernel.orghttps://git.kernel.org/stable/c/b627c6ba20be20334338229b4820baacb9d96826
- git.kernel.orghttps://git.kernel.org/stable/c/c9728fcf2e7fb4a7a8d08ebd9524c3b02ae1a021
No related CVEs by CWE or product.