On Fri, 2024-03-29 at 11:56 +0100, Roberto Sassu wrote: > From: Roberto Sassu <[email protected]> > > Commit 08abce60d63fi ("security: Introduce path_post_mknod hook") > introduced security_path_post_mknod(), to replace the IMA-specific call to > ima_post_path_mknod(). > > For symmetry with security_path_mknod(), security_path_post_mknod() is > called after a successful mknod operation, for any file type, rather than > only for regular files at the time there was the IMA call. > > However, as reported by VFS maintainers, successful mknod operation does > not mean that the dentry always has an inode attached to it (for example, > not for FIFOs on a SAMBA mount). > > If that condition happens, the kernel crashes when > security_path_post_mknod() attempts to verify if the inode associated to > the dentry is private. > > Add an extra check to first verify if there is an inode attached to the > dentry, before checking if the inode is private. Also add the same check to > the current users of the path_post_mknod hook, ima_post_path_mknod() and > evm_post_path_mknod(). > > Finally, use the proper helper, d_backing_inode(), to retrieve the inode > from the dentry in ima_post_path_mknod(). > > Cc: [email protected] # 6.8.x
Huh? It doesn't need to be backported. > Reported-by: Steve French <[email protected]> > Closes: > https://lore.kernel.org/linux-kernel/cah2r5msavzxcuhhg8vkrmpukqhmbpe6k9_vjhgda1uavwx4...@mail.gmail.com/ > Fixes: 08abce60d63fi ("security: Introduce path_post_mknod hook") -> 08abce60d63f > Signed-off-by: Roberto Sassu <[email protected]> Acked-by: Mimi Zohar <[email protected]>
