There are multiple similar bugs implicitly introduced by the commit c0cfa2d8a788fcf4 ("vsock: add multi-transports support") and commit 6a2c0962105ae8ce ("vsock: prevent transport modules unloading"). The bug pattern: [1] vsock_sock.transport pointer is copied to a local variable, [2] lock_sock() is called, [3] the local variable is used. VSOCK multi-transport support introduced the race condition: vsock_sock.transport value may change between [1] and [2]. Let's copy vsock_sock.transport pointer to local variables after the lock_sock() call. Fixes: c0cfa2d8a788fcf4 ("vsock: add multi-transports support") Signed-off-by: Alexander Popov <alex.popov@linux.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Jorgen Hansen <jhansen@vmware.com> Link: https://lore.kernel.org/r/20210201084719.2257066-1-alex.popov@linux.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. 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.
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