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[198.0.35.241]) by smtp.gmail.com with ESMTPSA id e12-20020a170902744c00b001cfca7b8ec4sm1789326plt.101.2023.11.30.12.02.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 30 Nov 2023 12:02:08 -0800 (PST) From: Kees Cook To: Jim Cromie Cc: Kees Cook , Jean Delvare , Guenter Roeck , linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH] hwmon: (pc87360) Bounds check data->innr usage Date: Thu, 30 Nov 2023 12:02:07 -0800 Message-Id: <20231130200207.work.679-kees@kernel.org> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-hwmon@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1892; i=keescook@chromium.org; h=from:subject:message-id; bh=2B9+0DQZw8GSK0K6KON3uBQG8TgW64VHj87FAuDhq9g=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBlaOo/anwlkPtl+uLLxq5xr0ZdwKLNISHKDG96w JsEAMB67dWJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCZWjqPwAKCRCJcvTf3G3A Jo6+EACMBXK6p8YSOtaHkRDySUePU+sU54WkTgPH2eeXNI6H0Aui7fZzVUIWtEkmW99rsheV0uE 5KIjxPIx7cl9NCJPRDFnqNzGYaN/mYQcp4MRxZWaKptsctgR92uI/LRs/D1Kxz9TF31EWP2vFi1 JtD+ot1vOm3OMRXNzvVrLKZeR3m5JHyxUp2OdFD8U8zPhOSDYfhPCNV2sfRihbOddG4lz2N3X87 PF8ezB8Ny8LzShDAAx6UhMFhkrFVkF9VgauWfX5yawVy+9n1sshNKc03lMx+C9w7RFi+/iaOmcX HsZWRaQFgcOJ+eaA6CITLRznzGb9HEFNkxrrvUWpefLPZpJvf32RL7Fht8vrv+ejEWTdrQCThCM lZ4hlOwotCUW5fV0sBwx5DgyeVBvPv3ALfiRgVWsURI17i8baDgCvO6v3rfVy1Fc9CR92XiV8g8 opxDLkBFY2/r6dNGXLvxTSDQgwo9TXZiTHAZGJmrG0l86r8BKe9lf4YrTT/1WHFCoDK7W3GWL05 UohpynVgfX5JFZofROWoJ3jd68KhNjZ4yOrmHrObI4o8LOFBDm9p8AvyQAYvyjmZ/UdS5g/7Zb3 96fFDYw73pqMI0/Um4dCST2Q6Jpdxqhw1J/58dJ9VOT3rRzNj1kXRSZ3VisuH6JdoZZ0v8wgqHK R4hlteN XXHoHMww== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Without visibility into the initializers for data->innr, GCC suspects using it as an index could walk off the end of the various 14-element arrays in data. Perform an explicit clamp to the array size. Silences the following warning with GCC 12+: ../drivers/hwmon/pc87360.c: In function 'pc87360_update_device': ../drivers/hwmon/pc87360.c:341:49: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=] 341 | data->in_max[i] = pc87360_read_value(data, | ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~ 342 | LD_IN, i, | ~~~~~~~~~ 343 | PC87365_REG_IN_MAX); | ~~~~~~~~~~~~~~~~~~~ ../drivers/hwmon/pc87360.c:209:12: note: at offset 255 into destination object 'in_max' of size 14 209 | u8 in_max[14]; /* Register value */ | ^~~~~~ Cc: Jim Cromie Cc: Jean Delvare Cc: Guenter Roeck Cc: linux-hwmon@vger.kernel.org Signed-off-by: Kees Cook Reviewed-by: Gustavo A. R. Silva --- drivers/hwmon/pc87360.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/hwmon/pc87360.c b/drivers/hwmon/pc87360.c index 926ea1fe133c..db80394ba854 100644 --- a/drivers/hwmon/pc87360.c +++ b/drivers/hwmon/pc87360.c @@ -323,7 +323,7 @@ static struct pc87360_data *pc87360_update_device(struct device *dev) } /* Voltages */ - for (i = 0; i < data->innr; i++) { + for (i = 0; i < min(data->innr, ARRAY_SIZE(data->in)); i++) { data->in_status[i] = pc87360_read_value(data, LD_IN, i, PC87365_REG_IN_STATUS); /* Clear bits */