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On a I2C_SMBUS_I2C_BLOCK_DATA read request, if data->block[0] is greater than I2C_SMBUS_BLOCK_MAX + 1, the underlying I2C driver writes data out of the msgbuf1 array boundary. It is possible from a user application to run into that issue by calling the I2C_SMBUS ioctl with data.block[0] greater than I2C_SMBUS_BLOCK_MAX + 1. This patch makes the code compliant with Documentation/i2c/dev-interface by raising an error when the requested size is larger than 32 bytes. Call Trace: [<ffffffff8139f695>] dump_stack+0x67/0x92 [<ffffffff811802a4>] panic+0xc5/0x1eb [<ffffffff810ecb5f>] ? vprintk_default+0x1f/0x30 [<ffffffff817456d3>] ? i2cdev_ioctl_smbus+0x303/0x320 [<ffffffff8109a68b>] __stack_chk_fail+0x1b/0x20 [<ffffffff817456d3>] i2cdev_ioctl_smbus+0x303/0x320 [<ffffffff81745aed>] i2cdev_ioctl+0x4d/0x1e0 [<ffffffff811f761a>] do_vfs_ioctl+0x2ba/0x490 [<ffffffff81336e43>] ? security_file_ioctl+0x43/0x60 [<ffffffff811f7869>] SyS_ioctl+0x79/0x90 [<ffffffff81a22e97>] entry_SYSCALL_64_fastpath+0x12/0x6a Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Cc: stable@kernel.org
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.