From 9cfcac810e8993fa7a5bfd24b1a21f1dbbb03a7b Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Fri, 23 Jul 2010 11:43:51 -0400 Subject: [PATCH] vfs: re-introduce MAY_CHDIR Currently MAY_ACCESS means that filesystems must check the permissions right then and not rely on cached results or the results of future operations on the object. This can be because of a call to sys_access() or because of a call to chdir() which needs to check search without relying on any future operations inside that dir. I plan to use MAY_ACCESS for other purposes in the security system, so I split the MAY_ACCESS and the MAY_CHDIR cases. Signed-off-by: Eric Paris Acked-by: Stephen D. Smalley Signed-off-by: James Morris --- fs/fuse/dir.c | 2 +- fs/nfs/dir.c | 2 +- fs/open.c | 6 +++--- include/linux/fs.h | 1 + 4 files changed, 6 insertions(+), 5 deletions(-) diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index 3cdc5f78a406..431be0795b6b 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -1016,7 +1016,7 @@ static int fuse_permission(struct inode *inode, int mask) exist. So if permissions are revoked this won't be noticed immediately, only after the attribute timeout has expired */ - } else if (mask & MAY_ACCESS) { + } else if (mask & (MAY_ACCESS | MAY_CHDIR)) { err = fuse_access(inode, mask); } else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) { if (!(inode->i_mode & S_IXUGO)) { diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index e60416d3f818..832e9e239324 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -1953,7 +1953,7 @@ int nfs_permission(struct inode *inode, int mask) if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0) goto out; /* Is this sys_access() ? */ - if (mask & MAY_ACCESS) + if (mask & (MAY_ACCESS | MAY_CHDIR)) goto force_lookup; switch (inode->i_mode & S_IFMT) { diff --git a/fs/open.c b/fs/open.c index a54ed85209c1..0d1fa3dc0efb 100644 --- a/fs/open.c +++ b/fs/open.c @@ -366,7 +366,7 @@ SYSCALL_DEFINE1(chdir, const char __user *, filename) if (error) goto out; - error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_ACCESS); + error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR); if (error) goto dput_and_out; @@ -395,7 +395,7 @@ SYSCALL_DEFINE1(fchdir, unsigned int, fd) if (!S_ISDIR(inode->i_mode)) goto out_putf; - error = inode_permission(inode, MAY_EXEC | MAY_ACCESS); + error = inode_permission(inode, MAY_EXEC | MAY_CHDIR); if (!error) set_fs_pwd(current->fs, &file->f_path); out_putf: @@ -413,7 +413,7 @@ SYSCALL_DEFINE1(chroot, const char __user *, filename) if (error) goto out; - error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_ACCESS); + error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR); if (error) goto dput_and_out; diff --git a/include/linux/fs.h b/include/linux/fs.h index 68ca1b0491af..7d94b72f0346 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -53,6 +53,7 @@ struct inodes_stat_t { #define MAY_APPEND 8 #define MAY_ACCESS 16 #define MAY_OPEN 32 +#define MAY_CHDIR 64 /* * flags in file.f_mode. Note that FMODE_READ and FMODE_WRITE must correspond -- 2.34.1