A-Team_Digital_Solutions/android_kernel_motorola_sm6375
Watch
2
0
Fork
You've already forked android_kernel_motorola_sm6375
 0
mirror of https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git synced 2026-10-29 03:01:39 -04:00
Code Issues Projects Releases Packages Wiki Activity

sysfs: fix race between readdir and lseek

Browse source 
While readdir() is running, lseek() may set filp->f_pos as zero,
then may leave filp->private_data pointing to one sysfs_dirent
object without holding its reference counter, so the sysfs_dirent
object may be used after free in next readdir().

This patch holds inode->i_mutex to avoid the problem since
the lock is always held in readdir path.

Reported-by: Dave Jones <[email protected]>
Tested-by: Sasha Levin <[email protected]>
Cc: <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
This commit is contained in:
Ming Lei 2013-03-20 23:25:24 +08:00 • committed by Greg Kroah-Hartman
commit 991f76f837
1 changed files with 12 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

13
fs/sysfs/dir.c
View file

@ -1058,10 +1058,21 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
return 0;
}
static loff_t sysfs_dir_llseek(struct file *file, loff_t offset, int whence)
{
struct inode *inode = file_inode(file);
loff_t ret;
mutex_lock(&inode->i_mutex);
ret = generic_file_llseek(file, offset, whence);
mutex_unlock(&inode->i_mutex);
return ret;
}
const struct file_operations sysfs_dir_operations = {
.read = generic_read_dir,
.readdir = sysfs_readdir,
.release = sysfs_dir_release,
.llseek = generic_file_llseek,
.llseek = sysfs_dir_llseek,
};