lkml.org 
[lkml]   [2007]   [Jun]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH 1/1] fs-sysfs bugfix of sysfs_hash_and_remove dereferencing before checking for NULL
From:	Douglas Thompson <dougthompson@xmission.com>

In tracking down one of my bugs in using sysfs, I found the kernel doing a NULL de-reference
in function fs/sysfs/inode.c:sysfs_hash_and_remove(), when I (incorrectly) passed
in a dentry value of NULL.

The check for NULL should occur BEFORE the dereference of 'dir'.
This patch modifies the sequence and does the check FIRST


Signed-off-by: Douglas Thompson <dougthompson@xmission.com>
---

Index: linux-2.6.22-rc4-mm2/fs/sysfs/inode.c
===================================================================
--- linux-2.6.22-rc4-mm2.orig/fs/sysfs/inode.c
+++ linux-2.6.22-rc4-mm2/fs/sysfs/inode.c
@@ -285,7 +285,7 @@ void sysfs_drop_dentry(struct sysfs_dire
int sysfs_hash_and_remove(struct dentry * dir, const char * name)
{
struct sysfs_dirent **pos, *sd;
- struct sysfs_dirent *parent_sd = dir->d_fsdata;
+ struct sysfs_dirent *parent_sd;
int found = 0;

if (!dir)
@@ -295,6 +295,8 @@ int sysfs_hash_and_remove(struct dentry
/* no inode means this hasn't been made visible yet */
return -ENOENT;

+ parent_sd = dir->d_fsdata;
+
mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
for (pos = &parent_sd->s_children; *pos; pos = &(*pos)->s_sibling) {
sd = *pos;
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2007-06-22 19:17    [W:0.029 / U:1.704 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site