> Trying to read the overlong target of a /proc/*/fd/N file descriptor
> leads with the current BK kernel to a segfault in the kernel.
Yes. Below a patch.
Andries
diff -u --recursive --new-file -X /linux/dontdiff a/fs/proc/base.c b/fs/proc/base.c
--- a/fs/proc/base.c Sun Feb 23 22:47:55 2003
+++ b/fs/proc/base.c Sun Mar 30 14:32:35 2003
@@ -565,10 +565,10 @@
}
static int do_proc_readlink(struct dentry *dentry, struct vfsmount *mnt,
- char * buffer, int buflen)
+ char *buffer, int buflen)
{
struct inode * inode;
- char * tmp = (char*)__get_free_page(GFP_KERNEL), *path;
+ char *tmp = (char*)__get_free_page(GFP_KERNEL), *path;
int len;
if (!tmp)
@@ -576,13 +576,17 @@
inode = dentry->d_inode;
path = d_path(dentry, mnt, tmp, PAGE_SIZE);
+ len = PTR_ERR(path);
+ if (IS_ERR(path))
+ goto out;
len = tmp + PAGE_SIZE - 1 - path;
- if (len < buflen)
- buflen = len;
- copy_to_user(buffer, path, buflen);
+ if (len > buflen)
+ len = buflen;
+ copy_to_user(buffer, path, len);
+ out:
free_page((unsigned long)tmp);
- return buflen;
+ return len;
}
static int proc_pid_readlink(struct dentry * dentry, char * buffer, int buflen)