diff options
| author | Linus Torvalds <torvalds@evo.osdl.org> | 2006-07-15 12:26:45 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@evo.osdl.org> | 2006-07-15 12:26:45 -0700 |
| commit | 6d76fa58b050044994fe25f8753b8023f2b36737 (patch) | |
| tree | 86964d8aeb297fe4346f73d812519646c7fdca20 | |
| parent | 92d032855e64834283de5acfb0463232e0ab128e (diff) | |
| download | linux-6d76fa58b050044994fe25f8753b8023f2b36737.tar.gz | |
Don't allow chmod() on the /proc/<pid>/ files
This just turns off chmod() on the /proc/<pid>/ files, since there is no
good reason to allow it, and had we disallowed it originally, the nasty
/proc race exploit wouldn't have been possible.
The other patches already fixed the problem chmod() could cause, so this
is really just some final mop-up..
This particular version is based off a patch by Eugene and Marcel which
had much better naming than my original equivalent one.
Signed-off-by: Eugene Teo <eteo@redhat.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | fs/proc/base.c | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index 474eae34506833..fe8d55fb17cc37 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -551,6 +551,27 @@ static int proc_fd_access_allowed(struct inode *inode) return allowed; } +static int proc_setattr(struct dentry *dentry, struct iattr *attr) +{ + int error; + struct inode *inode = dentry->d_inode; + + if (attr->ia_valid & ATTR_MODE) + return -EPERM; + + error = inode_change_ok(inode, attr); + if (!error) { + error = security_inode_setattr(dentry, attr); + if (!error) + error = inode_setattr(inode, attr); + } + return error; +} + +static struct inode_operations proc_def_inode_operations = { + .setattr = proc_setattr, +}; + extern struct seq_operations mounts_op; struct proc_mounts { struct seq_file m; @@ -1111,7 +1132,8 @@ out: static struct inode_operations proc_pid_link_inode_operations = { .readlink = proc_pid_readlink, - .follow_link = proc_pid_follow_link + .follow_link = proc_pid_follow_link, + .setattr = proc_setattr, }; static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir) @@ -1285,6 +1307,7 @@ static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_st ei = PROC_I(inode); inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; inode->i_ino = fake_ino(task->pid, ino); + inode->i_op = &proc_def_inode_operations; /* * grab the reference to task. @@ -1529,11 +1552,13 @@ static struct file_operations proc_task_operations = { */ static struct inode_operations proc_fd_inode_operations = { .lookup = proc_lookupfd, + .setattr = proc_setattr, }; static struct inode_operations proc_task_inode_operations = { .lookup = proc_task_lookup, .getattr = proc_task_getattr, + .setattr = proc_setattr, }; #ifdef CONFIG_SECURITY @@ -1847,11 +1872,13 @@ static struct file_operations proc_tid_base_operations = { static struct inode_operations proc_tgid_base_inode_operations = { .lookup = proc_tgid_base_lookup, .getattr = pid_getattr, + .setattr = proc_setattr, }; static struct inode_operations proc_tid_base_inode_operations = { .lookup = proc_tid_base_lookup, .getattr = pid_getattr, + .setattr = proc_setattr, }; #ifdef CONFIG_SECURITY @@ -1894,11 +1921,13 @@ static struct dentry *proc_tid_attr_lookup(struct inode *dir, static struct inode_operations proc_tgid_attr_inode_operations = { .lookup = proc_tgid_attr_lookup, .getattr = pid_getattr, + .setattr = proc_setattr, }; static struct inode_operations proc_tid_attr_inode_operations = { .lookup = proc_tid_attr_lookup, .getattr = pid_getattr, + .setattr = proc_setattr, }; #endif |