From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-74391: tracing: Bound synthetic-field strings with seq_buf
Date: Sat, 15 Aug 2026 15:11:58 +0900 [thread overview]
Message-ID: <2026081507-CVE-2026-74391-e5be@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
tracing: Bound synthetic-field strings with seq_buf
The synthetic field helpers build a prefixed synthetic variable name and
a generated hist command in fixed MAX_FILTER_STR_VAL buffers. The
current code appends those strings with raw strcat(), so long key lists,
field names, or saved filters can run past the end of the staging
buffers.
Build both strings with seq_buf and propagate -E2BIG if either the
synthetic variable name or the generated command exceeds
MAX_FILTER_STR_VAL. This keeps the existing tracing-side limit while
using the helper intended for bounded command construction.
[ sdr: Moved struct seq_buf *s for upside-down x-mas tree formatting ]
The Linux kernel CVE team has assigned CVE-2026-74391 to this issue.
Affected and fixed versions
===========================
Issue introduced in 4.17 with commit 02205a6752f223779a1b0e9e8ffacbea6e717851 and fixed in 6.6.145 with commit 0c584c27f6649a93ec12061cc779a4bd8f7c1434
Issue introduced in 4.17 with commit 02205a6752f223779a1b0e9e8ffacbea6e717851 and fixed in 6.12.97 with commit 88b901fdc1662b131ff908cbd017333b61e7acc8
Issue introduced in 4.17 with commit 02205a6752f223779a1b0e9e8ffacbea6e717851 and fixed in 6.18.40 with commit baa333b2700a7fa3529d504529c8c10060fd687c
Issue introduced in 4.17 with commit 02205a6752f223779a1b0e9e8ffacbea6e717851 and fixed in 7.1.5 with commit cf334620036ad2250e008c7e7bb6646a3938b7b0
Issue introduced in 4.17 with commit 02205a6752f223779a1b0e9e8ffacbea6e717851 and fixed in 7.2-rc1 with commit f07883450eb14d1cf020b55d9f3a7ec5683bcd26
Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.
Unaffected versions might change over time as fixes are backported to
older supported kernel versions. The official CVE entry at
https://cve.org/CVERecord/?id=CVE-2026-74391
will be updated if fixes are backported, please check that for the most
up to date information about this issue.
Affected files
==============
The file(s) affected by this issue are:
kernel/trace/trace_events_hist.c
Mitigation
==========
The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes. Individual
changes are never tested alone, but rather are part of a larger kernel
release. Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all. If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
https://git.kernel.org/stable/c/0c584c27f6649a93ec12061cc779a4bd8f7c1434
https://git.kernel.org/stable/c/88b901fdc1662b131ff908cbd017333b61e7acc8
https://git.kernel.org/stable/c/baa333b2700a7fa3529d504529c8c10060fd687c
https://git.kernel.org/stable/c/cf334620036ad2250e008c7e7bb6646a3938b7b0
https://git.kernel.org/stable/c/f07883450eb14d1cf020b55d9f3a7ec5683bcd26
reply other threads:[~2026-08-15 6:38 UTC|newest]
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