aboutsummaryrefslogtreecommitdiff
path: root/fs
diff options
context:
space:
mode:
authorMing Lei <ming.lei@canonical.com>2013-03-20 23:25:25 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-03-20 16:53:42 -0700
commite5110f411d2ee35bf8d202ccca2e89c633060dca (patch)
tree9fe7297901679cca05b459f9e7e524e99c534a7d /fs
parent991f76f837bf22c5bb07261cfd86525a0a96650c (diff)
downloadvexpress-lsk-e5110f411d2ee35bf8d202ccca2e89c633060dca.tar.gz
sysfs: handle failure path correctly for readdir()
In case of 'if (filp->f_pos == 0 or 1)' of sysfs_readdir(), the failure from filldir() isn't handled, and the reference counter of the sysfs_dirent object pointed by filp->private_data will be released without clearing filp->private_data, so use after free bug will be triggered later. This patch returns immeadiately under the situation for fixing the bug, and it is reasonable to return from readdir() when filldir() fails. Reported-by: Dave Jones <davej@redhat.com> Tested-by: Sasha Levin <levinsasha928@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/sysfs/dir.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index c9e16608f48..e14512678c9 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -1020,6 +1020,8 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
ino = parent_sd->s_ino;
if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) == 0)
filp->f_pos++;
+ else
+ return 0;
}
if (filp->f_pos == 1) {
if (parent_sd->s_parent)
@@ -1028,6 +1030,8 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
ino = parent_sd->s_ino;
if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) == 0)
filp->f_pos++;
+ else
+ return 0;
}
mutex_lock(&sysfs_mutex);
for (pos = sysfs_dir_pos(ns, parent_sd, filp->f_pos, pos);