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authorLinus Torvalds <torvalds@evo.osdl.org>2006-07-15 12:26:45 -0700
committerLinus Torvalds <torvalds@evo.osdl.org>2006-07-15 12:26:45 -0700
commit6d76fa58b050044994fe25f8753b8023f2b36737 (patch)
tree86964d8aeb297fe4346f73d812519646c7fdca20 /fs
parent92d032855e64834283de5acfb0463232e0ab128e (diff)
downloadlwn-6d76fa58b050044994fe25f8753b8023f2b36737.tar.gz
lwn-6d76fa58b050044994fe25f8753b8023f2b36737.zip
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>
Diffstat (limited to 'fs')
-rw-r--r--fs/proc/base.c31
1 files changed, 30 insertions, 1 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 474eae345068..fe8d55fb17cc 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