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authorLi Zefan <lizf@cn.fujitsu.com>2008-11-19 15:36:48 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2008-11-19 18:50:00 -0800
commit33d283bef23132c48195eafc21449f8ba88fce6b (patch)
treee4a04851127f2f46122cb96fc13e8da71a7bcf10 /kernel/cgroup.c
parentea7e743e49b94749fc739baaf160809ed279aeda (diff)
downloadlinux-33d283bef23132c48195eafc21449f8ba88fce6b.tar.bz2
cgroups: fix a serious bug in cgroupstats
Try this, and you'll get oops immediately: # cd Documentation/accounting/ # gcc -o getdelays getdelays.c # mount -t cgroup -o debug xxx /mnt # ./getdelays -C /mnt/tasks Because a normal file's dentry->d_fsdata is a pointer to struct cftype, not struct cgroup. After the patch, it returns EINVAL if we try to get cgroupstats from a normal file. Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x, 2.6.27.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/cgroup.c')
-rw-r--r--kernel/cgroup.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 1a06be61dcd0..fe00b3b983a8 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2039,10 +2039,13 @@ int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry)
struct cgroup *cgrp;
struct cgroup_iter it;
struct task_struct *tsk;
+
/*
- * Validate dentry by checking the superblock operations
+ * Validate dentry by checking the superblock operations,
+ * and make sure it's a directory.
*/
- if (dentry->d_sb->s_op != &cgroup_ops)
+ if (dentry->d_sb->s_op != &cgroup_ops ||
+ !S_ISDIR(dentry->d_inode->i_mode))
goto err;
ret = 0;