From b68680e4731abbd78863063aaa0dca2a6d8cc723 Mon Sep 17 00:00:00 2001 From: "Serge E. Hallyn" Date: Sun, 21 Oct 2007 16:41:38 -0700 Subject: [PATCH] capabilities: clean up file capability reading Simplify the vfs_cap_data structure. Also fix get_file_caps which was declaring __le32 v1caps[XATTR_CAPS_SZ] on the stack, but XATTR_CAPS_SZ is already * sizeof(__le32). [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Serge E. Hallyn Cc: Andrew Morgan Cc: Chris Wright Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/capability.h | 6 ++---- security/commoncap.c | 23 +++++++++++++++-------- 2 files changed, 17 insertions(+), 12 deletions(-) diff --git a/include/linux/capability.h b/include/linux/capability.h index 7a8d7ade28a..bb017edffd5 100644 --- a/include/linux/capability.h +++ b/include/linux/capability.h @@ -56,10 +56,8 @@ typedef struct __user_cap_data_struct { struct vfs_cap_data { __u32 magic_etc; /* Little endian */ - struct { - __u32 permitted; /* Little endian */ - __u32 inheritable; /* Little endian */ - } data[1]; + __u32 permitted; /* Little endian */ + __u32 inheritable; /* Little endian */ }; #ifdef __KERNEL__ diff --git a/security/commoncap.c b/security/commoncap.c index 43f902750a1..bf67871173e 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -190,7 +190,8 @@ int cap_inode_killpriv(struct dentry *dentry) return inode->i_op->removexattr(dentry, XATTR_NAME_CAPS); } -static inline int cap_from_disk(__le32 *caps, struct linux_binprm *bprm, +static inline int cap_from_disk(struct vfs_cap_data *caps, + struct linux_binprm *bprm, int size) { __u32 magic_etc; @@ -198,7 +199,7 @@ static inline int cap_from_disk(__le32 *caps, struct linux_binprm *bprm, if (size != XATTR_CAPS_SZ) return -EINVAL; - magic_etc = le32_to_cpu(caps[0]); + magic_etc = le32_to_cpu(caps->magic_etc); switch ((magic_etc & VFS_CAP_REVISION_MASK)) { case VFS_CAP_REVISION: @@ -206,8 +207,8 @@ static inline int cap_from_disk(__le32 *caps, struct linux_binprm *bprm, bprm->cap_effective = true; else bprm->cap_effective = false; - bprm->cap_permitted = to_cap_t( le32_to_cpu(caps[1]) ); - bprm->cap_inheritable = to_cap_t( le32_to_cpu(caps[2]) ); + bprm->cap_permitted = to_cap_t(le32_to_cpu(caps->permitted)); + bprm->cap_inheritable = to_cap_t(le32_to_cpu(caps->inheritable)); return 0; default: return -EINVAL; @@ -219,7 +220,7 @@ static int get_file_caps(struct linux_binprm *bprm) { struct dentry *dentry; int rc = 0; - __le32 v1caps[XATTR_CAPS_SZ]; + struct vfs_cap_data incaps; struct inode *inode; if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID) { @@ -232,8 +233,14 @@ static int get_file_caps(struct linux_binprm *bprm) if (!inode->i_op || !inode->i_op->getxattr) goto out; - rc = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, &v1caps, - XATTR_CAPS_SZ); + rc = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, NULL, 0); + if (rc > 0) { + if (rc == XATTR_CAPS_SZ) + rc = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, + &incaps, XATTR_CAPS_SZ); + else + rc = -EINVAL; + } if (rc == -ENODATA || rc == -EOPNOTSUPP) { /* no data, that's ok */ rc = 0; @@ -242,7 +249,7 @@ static int get_file_caps(struct linux_binprm *bprm) if (rc < 0) goto out; - rc = cap_from_disk(v1caps, bprm, rc); + rc = cap_from_disk(&incaps, bprm, rc); if (rc) printk(KERN_NOTICE "%s: cap_from_disk returned %d for %s\n", __FUNCTION__, rc, bprm->filename); -- 2.41.1