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From: Azeem Shaikh <azeemshaikh38@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: linux-hardening@vger.kernel.org,
	Azeem Shaikh <azeemshaikh38@gmail.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@kernel.org>, Namhyung Kim <namhyung@kernel.org>,
	Ian Rogers <irogers@google.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] perf: Replace strlcpy with strscpy
Date: Mon,  3 Jul 2023 16:58:16 +0000	[thread overview]
Message-ID: <20230703165817.2840457-1-azeemshaikh38@gmail.com> (raw)

strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
---
 kernel/events/core.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 78ae7b6f90fd..2554f5fc70dc 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -8249,7 +8249,7 @@ static void perf_event_comm_event(struct perf_comm_event *comm_event)
 	unsigned int size;
 
 	memset(comm, 0, sizeof(comm));
-	strlcpy(comm, comm_event->task->comm, sizeof(comm));
+	strscpy(comm, comm_event->task->comm, sizeof(comm));
 	size = ALIGN(strlen(comm)+1, sizeof(u64));
 
 	comm_event->comm = comm;
@@ -8704,7 +8704,7 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
 	}
 
 cpy_name:
-	strlcpy(tmp, name, sizeof(tmp));
+	strscpy(tmp, name, sizeof(tmp));
 	name = tmp;
 got_name:
 	/*
@@ -9128,7 +9128,7 @@ void perf_event_ksymbol(u16 ksym_type, u64 addr, u32 len, bool unregister,
 	    ksym_type == PERF_RECORD_KSYMBOL_TYPE_UNKNOWN)
 		goto err;
 
-	strlcpy(name, sym, KSYM_NAME_LEN);
+	strscpy(name, sym, KSYM_NAME_LEN);
 	name_len = strlen(name) + 1;
 	while (!IS_ALIGNED(name_len, sizeof(u64)))
 		name[name_len++] = '\0';
-- 
2.41.0.255.g8b1d071c50-goog



             reply	other threads:[~2023-07-03 16:58 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-03 16:58 Azeem Shaikh [this message]
2023-07-12 23:43 ` [PATCH] perf: Replace strlcpy with strscpy Kees Cook
2023-07-27 15:52 ` Kees Cook

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