This patch solves CVE-2007-3104 - sysfs_readdir oops.
More can be found here:
http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.22.y.git;a=commit;h=dc35125...
Signed-off-by: Miloslav Semler
---
diff -uprN linux-2.6.16.53/fs/sysfs/dir.c linux-2.6.16.53-new/fs/sysfs/dir.c
--- linux-2.6.16.53/fs/sysfs/dir.c 2007-07-25 23:05:45.000000000 +0200
+++ linux-2.6.16.53-new/fs/sysfs/dir.c 2007-09-23 18:18:09.000000000 +0200
@@ -29,6 +29,14 @@ static struct dentry_operations sysfs_de
.d_iput = sysfs_d_iput,
};
+static unsigned int sysfs_inode_counter;
+ino_t sysfs_get_inum(void)
+{
+ if (unlikely(sysfs_inode_counter < 3))
+ sysfs_inode_counter = 3;
+ return sysfs_inode_counter++;
+}
+
/*
* Allocates a new sysfs_dirent and links it to the parent sysfs_dirent
*/
@@ -40,8 +48,10 @@ static struct sysfs_dirent * sysfs_new_d
sd = kmem_cache_alloc(sysfs_dir_cachep, GFP_KERNEL);
if (!sd)
return NULL;
+
memset(sd, 0, sizeof(*sd));
+ sd->s_ino = sysfs_get_inum();
atomic_set(&sd->s_count, 1);
INIT_LIST_HEAD(&sd->s_children);
list_add(&sd->s_sibling, &parent_sd->s_children);
@@ -385,7 +395,7 @@ static int sysfs_readdir(struct file * f
switch (i) {
case 0:
- ino = dentry->d_inode->i_ino;
+ ino = parent_sd->s_ino;
if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
break;
filp->f_pos++;
@@ -415,10 +425,7 @@ static int sysfs_readdir(struct file * f
name = sysfs_get_name(next);
len = strlen(name);
- if (next->s_dentry)
- ino =
next->s_dentry->d_inode->i_ino;
- else
- ino = iunique(sysfs_sb, 2);
+ ino = next->s_ino;
if (filldir(dirent, name, len,
filp->f_pos, ino,
dt_type(next)) < 0)
diff -uprN linux-2.6.16.53/fs/sysfs/inode.c
linux-2.6.16.53-new/fs/sysfs/inode.c
--- linux-2.6.16.53/fs/sysfs/inode.c 2007-07-25 23:05:45.000000000 +0200
+++ linux-2.6.16.53-new/fs/sysfs/inode.c 2007-09-23
18:18:09.000000000 +0200
@@ -119,6 +119,7 @@ struct inode * sysfs_new_inode(mode_t mo
inode->i_mapping->a_ops = &sysfs_aops;
inode->i_mapping->backing_dev_info =
&sysfs_backing_dev_info;
inode->i_op = &sysfs_inode_operations;
+ inode->i_ino = sd->s_ino;
if (sd->s_iattr) {
/* sysfs_dirent has non-default attributes
diff -uprN linux-2.6.16.53/fs/sysfs/mount.c
linux-2.6.16.53-new/fs/sysfs/mount.c
--- linux-2.6.16.53/fs/sysfs/mount.c 2007-07-25 23:05:45.000000000 +0200
+++ linux-2.6.16.53-new/fs/sysfs/mount.c 2007-09-23
18:18:09.000000000 +0200
@@ -29,6 +29,7 @@ static struct sysfs_dirent sysfs_root =
.s_element = NULL,
.s_type = SYSFS_ROOT,
.s_iattr = NULL,
+ .s_ino = 1,
};
static int sysfs_fill_super(struct super_block *sb, void *data, int silent)
diff -uprN linux-2.6.16.53/include/linux/sysfs.h
linux-2.6.16.53-new/include/linux/sysfs.h
--- linux-2.6.16.53/include/linux/sysfs.h 2007-07-25
23:05:45.000000000 +0200
+++ linux-2.6.16.53-new/include/linux/sysfs.h 2007-09-23
18:18:09.000000000 +0200
@@ -72,6 +72,7 @@ struct sysfs_dirent {
void * s_element;
int s_type;
umode_t s_mode;
+ ino_t s_ino;
struct dentry * s_dentry;
struct iattr * s_iattr;
};
-
