Re: [RFC PATCH v9 12/16] fsverity: consume builtin signature via LSM hook
From: Eric Biggers <ebiggers@kernel.org>
Date: 2023-02-09 03:31:33
Also in:
dm-devel, linux-block, linux-doc, linux-fscrypt, linux-integrity, lkml
So disregarding the fact that using the fsverity builtin signatures still seems like a bad idea to me, here's a few comments on the diff itself: On Mon, Jan 30, 2023 at 02:57:27PM -0800, Fan Wu wrote:
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diff --git a/fs/verity/open.c b/fs/verity/open.c index 81ff94442f7b..7e6fa52c0e9c 100644 --- a/fs/verity/open.c +++ b/fs/verity/open.c@@ -7,7 +7,9 @@ #include "fsverity_private.h" +#include <linux/security.h> #include <linux/slab.h> +#include <crypto/public_key.h>
There's no need to include <crypto/public_key.h>.
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static struct kmem_cache *fsverity_info_cachep;@@ -146,7 +148,7 @@ static int compute_file_digest(struct fsverity_hash_alg *hash_alg, * appended signature), and check the signature if present. The * fsverity_descriptor must have already undergone basic validation. */ -struct fsverity_info *fsverity_create_info(const struct inode *inode, +struct fsverity_info *fsverity_create_info(struct inode *inode, struct fsverity_descriptor *desc) { struct fsverity_info *vi;@@ -182,6 +184,15 @@ struct fsverity_info *fsverity_create_info(const struct inode *inode, err = fsverity_verify_signature(vi, desc->signature, le32_to_cpu(desc->sig_size)); + if (err) { + fsverity_err(inode, "Error %d verifying signature", err); + goto out; + }
The above error message is unnecessary because fsverity_verify_signature() already prints an error message on failure.
+ + err = security_inode_setsecurity(inode, FS_VERITY_INODE_SEC_NAME, desc->signature, + le32_to_cpu(desc->sig_size), 0);
This runs even if CONFIG_FS_VERITY_BUILTIN_SIGNATURES is disabled. Is that really the right behavior? Also a nit: please stick to the preferred line length of 80 characters. See Documentation/process/coding-style.rst
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diff --git a/fs/verity/signature.c b/fs/verity/signature.c index 143a530a8008..5d7b9496f9c4 100644 --- a/fs/verity/signature.c +++ b/fs/verity/signature.c@@ -9,6 +9,7 @@ #include <linux/cred.h> #include <linux/key.h> +#include <linux/security.h> #include <linux/slab.h> #include <linux/verification.h>
This change is unnecessary.
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diff --git a/include/linux/fsverity.h b/include/linux/fsverity.h index 40f14e5fed9d..29e9888287ba 100644 --- a/include/linux/fsverity.h +++ b/include/linux/fsverity.h@@ -254,4 +254,6 @@ static inline bool fsverity_active(const struct inode *inode) return fsverity_get_info(inode) != NULL; } +#define FS_VERITY_INODE_SEC_NAME "fsverity.inode-info"
"inode-info" is very vague. Shouldn't it be named "builtin-sig" or something? - Eric