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([2409:4080:204:a537:5da0:ac0c:6934:f07]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-306df4011f1sm3438980a91.41.2025.04.10.03.34.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Apr 2025 03:34:55 -0700 (PDT) From: Purva Yeshi To: peterhuewe@gmx.de, jarkko@kernel.org Cc: jgg@ziepe.ca, linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, Purva Yeshi Subject: [PATCH v2] char: tpm: tpm-buf: Add sanity check fallback in read helpers Date: Thu, 10 Apr 2025 16:04:42 +0530 Message-Id: <20250410103442.17746-1-purvayeshi550@gmail.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-integrity@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Fix Smatch-detected issue: drivers/char/tpm/tpm-buf.c:208 tpm_buf_read_u8() error: uninitialized symbol 'value'. drivers/char/tpm/tpm-buf.c:225 tpm_buf_read_u16() error: uninitialized symbol 'value'. drivers/char/tpm/tpm-buf.c:242 tpm_buf_read_u32() error: uninitialized symbol 'value'. Zero-initialize the return values in tpm_buf_read_u8(), tpm_buf_read_u16(), and tpm_buf_read_u32() to guard against uninitialized data in case of a boundary overflow. Add defensive initialization ensures the return values are always defined, preventing undefined behavior if the unexpected happens. Signed-off-by: Purva Yeshi Reviewed-by: Jarkko Sakkinen Reviewed-by: Stefano Garzarella --- V1 - https://lore.kernel.org/all/20250409205536.210202-1-purvayeshi550@gmail.com/ V2 - Update commit message to clarify patch adds a sanity check drivers/char/tpm/tpm-buf.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c index e49a19fea3bd..dc882fc9fa9e 100644 --- a/drivers/char/tpm/tpm-buf.c +++ b/drivers/char/tpm/tpm-buf.c @@ -201,7 +201,7 @@ static void tpm_buf_read(struct tpm_buf *buf, off_t *offset, size_t count, void */ u8 tpm_buf_read_u8(struct tpm_buf *buf, off_t *offset) { - u8 value; + u8 value = 0; tpm_buf_read(buf, offset, sizeof(value), &value); @@ -218,7 +218,7 @@ EXPORT_SYMBOL_GPL(tpm_buf_read_u8); */ u16 tpm_buf_read_u16(struct tpm_buf *buf, off_t *offset) { - u16 value; + u16 value = 0; tpm_buf_read(buf, offset, sizeof(value), &value); @@ -235,7 +235,7 @@ EXPORT_SYMBOL_GPL(tpm_buf_read_u16); */ u32 tpm_buf_read_u32(struct tpm_buf *buf, off_t *offset) { - u32 value; + u32 value = 0; tpm_buf_read(buf, offset, sizeof(value), &value);