On Jul 11, 2024 Xu Kuohai xukuohai@huaweicloud.com wrote:
To be consistent with most LSM hooks, convert the return value of hook inode_getsecurity to 0 or a negative error code.
Before:
- Hook inode_getsecurity returns size of buffer on success or a negative error code on failure.
After:
- Hook inode_getsecurity returns 0 on success or a negative error code on failure. An output parameter @len is introduced to hold the buffer size on success.
Signed-off-by: Xu Kuohai xukuohai@huawei.com
fs/xattr.c | 19 ++++++++++--------- include/linux/lsm_hook_defs.h | 3 ++- include/linux/security.h | 12 ++++++------ security/commoncap.c | 9 ++++++--- security/security.c | 11 ++++++----- security/selinux/hooks.c | 16 ++++++---------- security/smack/smack_lsm.c | 14 +++++++------- 7 files changed, 43 insertions(+), 41 deletions(-)
Aside from Simon's concern over variable types, I saw a few other issues when looking at this patch (below).
diff --git a/security/commoncap.c b/security/commoncap.c index 17d6188d22cf..ff82e2ab6f8f 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -485,7 +485,10 @@ int cap_inode_getsecurity(struct mnt_idmap *idmap, } out_free: kfree(tmpbuf);
- return size;
- if (size < 0)
return size;- *len = size;
- return 0;
}
We should do a better job converting cap_inode_getsecurity(), create a new local variable, e.g. 'int error', and use it to store and return the error code instead of reusing @size. I understand that what you've done is easier, but I'd prefer to see it done properly.
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 9cd5a8f1f6a3..70792bba24d9 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3407,7 +3407,7 @@ static int selinux_path_notify(const struct path *path, u64 mask, */ static int selinux_inode_getsecurity(struct mnt_idmap *idmap, struct inode *inode, const char *name,
void **buffer, bool alloc)
bool alloc, void **buffer, u32 *len){ u32 size; int error; @@ -3440,14 +3440,14 @@ static int selinux_inode_getsecurity(struct mnt_idmap *idmap, &context, &size); if (error) return error;
- error = size;
- *len = size;
Depending on how you choose to resolve the variable type issue, you may be able to pass @len directly to security_sid_to_context().
if (alloc) { *buffer = context; goto out_nofree; } kfree(context); out_nofree:
- return error;
- return 0;
}
-- paul-moore.com