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(109-252-120-31.nat.spd-mgts.ru. [109.252.120.31]) by smtp.gmail.com with ESMTPSA id 2adb3069b0e04-550e7017ea8sm1998021e87.113.2025.05.19.12.26.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 19 May 2025 12:26:01 -0700 (PDT) From: ant.v.moryakov@gmail.com To: trix@redhat.com Cc: linux-kernel@vger.kernel.org, Anton Moryakov Subject: [PATCH v2] tiny-printf: handle NULL pointer for %s format string Date: Mon, 19 May 2025 22:25:57 +0300 Message-Id: <20250519192557.1505924-1-ant.v.moryakov@gmail.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Anton Moryakov Avoid NULL pointer dereference in string formatting by printing "(null)" when a NULL pointer is passed to a %s format specifier. This change makes the behavior consistent with standard printf() implementations and prevents potential crashes in constrained environments. Signed-off-by: Anton Moryakov --- lib/tiny-printf.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/lib/tiny-printf.c b/lib/tiny-printf.c index 2a7a4d286c0..df5f6829db5 100644 --- a/lib/tiny-printf.c +++ b/lib/tiny-printf.c @@ -307,6 +307,8 @@ static int _vprintf(struct printf_info *info, const cha= r *fmt, va_list va) break; case 's': p =3D va_arg(va, char*); + if (!p) + p =3D "(null)"; break; case '%': out(info, '%'); --=20 2.34.1