On Tue, Mar 05, 2024 at 01:27:06PM +0100, Christian Brauner wrote: > The vfs_getxattr_alloc() interface is a special-purpose in-kernel api > that does a racy query-size+allocate-buffer+retrieve-data. It is used by > EVM, IMA, and fscaps to retrieve xattrs. Recently, we've seen issues > where 9p returned values that amount to allocating about 8000GB worth of > memory (cf. [1]). That's now fixed in 9p. But vfs_getxattr_alloc() has > no reason to allow getting xattr values that are larger than > XATTR_MAX_SIZE as that's the limit we use for setting and getting xattr > values and nothing currently goes beyond that limit afaict. Let it check > for that and reject requests that are larger than that. > > Link: https://lore.kernel.org/r/ZeXcQmHWcYvfCR93@do-x1extreme [1] > Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx> Makes sense. Reviewed-by: Seth Forshee (DigitalOcean) <sforshee@xxxxxxxxxx>
