CVE-2025-38493
- Source
- https://nvd.nist.gov/vuln/detail/CVE-2025-38493
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-38493.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2025-38493
- Downstream
- Related
- Published
- 2025-07-28T11:22:02Z
- Modified
- 2025-10-22T14:49:39.934461Z
- Summary
- tracing/osnoise: Fix crash in timerlat_dump_stack()
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
tracing/osnoise: Fix crash in timerlatdumpstack()
We have observed kernel panics when using timerlat with stack saving, with the following dmesg output:
memcpy: detected buffer overflow: 88 byte write of buffer size 0 WARNING: CPU: 2 PID: 8153 at lib/stringhelpers.c:1032 _fortifyreport+0x55/0xa0 CPU: 2 UID: 0 PID: 8153 Comm: timerlatu/2 Kdump: loaded Not tainted 6.15.3-200.fc42.x8664 #1 PREEMPT(lazy) Call Trace: <TASK> ? tracebufferlockreserve+0x2a/0x60 _fortifypanic+0xd/0xf _timerlatdumpstack.cold+0xd/0xd timerlatdumpstack.part.0+0x47/0x80 timerlatfdread+0x36d/0x390 vfsread+0xe2/0x390 ? syscallexittousermode+0x1d5/0x210 ksysread+0x73/0xe0 dosyscall64+0x7b/0x160 ? excpagefault+0x7e/0x1a0 entrySYSCALL64afterhwframe+0x76/0x7e
_timerlatdump_stack() constructs the ftrace stack entry like this:
struct stackentry *entry; ... memcpy(&entry->caller, fstack->calls, size); entry->size = fstack->nrentries;
Since commit e7186af7fb26 ("tracing: Add back FORTIFYSOURCE logic to kernelstack event structure"), struct stackentry marks its caller field with _counted_by(size). At the time of the memcpy, entry->size contains garbage from the ringbuffer, which under some circumstances is zero, triggering a kernel panic by buffer overflow.
Populate the size field before the memcpy so that the out-of-bounds check knows the correct size. This is analogous to _ftracetrace_stack().
- References
-
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/7bb9ea515cda027c9e717e27fefcf34f092e7c41
- https://git.kernel.org/stable/c/823d798900481875ba6c68217af028c5ffd2976b
- https://git.kernel.org/stable/c/85a3bce695b361d85fc528e6fbb33e4c8089c806
- https://git.kernel.org/stable/c/fbf90f5aa7ac7cddc69148a71d58f12c8709ce2b
Affected packages
Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected ranges
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducede7186af7fb2609584a8bfb3da3c6ae09da5a5224Fixed823d798900481875ba6c68217af028c5ffd2976b
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducede7186af7fb2609584a8bfb3da3c6ae09da5a5224Fixed7bb9ea515cda027c9e717e27fefcf34f092e7c41
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducede7186af7fb2609584a8bfb3da3c6ae09da5a5224Fixedfbf90f5aa7ac7cddc69148a71d58f12c8709ce2b
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducede7186af7fb2609584a8bfb3da3c6ae09da5a5224Fixed85a3bce695b361d85fc528e6fbb33e4c8089c806