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author | Li Zefan <lizefan@huawei.com> | 2013-04-19 06:09:52 (GMT) |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-05-08 03:08:22 (GMT) |
commit | fdb2b6f6dfc7b5a1c741a677eb990070690958f7 (patch) | |
tree | 1b2c2f5a8af166416387ee346b54f8b370d1f423 /kernel | |
parent | 1ef527a1111b2a206d39d2e23cf13819e329f8b4 (diff) | |
download | linux-fsl-qoriq-fdb2b6f6dfc7b5a1c741a677eb990070690958f7.tar.xz |
cgroup: fix broken file xattrs
commit 712317ad97f41e738e1a19aa0a6392a78a84094e upstream.
We should store file xattrs in struct cfent instead of struct cftype,
because cftype is a type while cfent is object instance of cftype.
For example each cgroup has a tasks file, and each tasks file is
associated with a uniq cfent, but all those files share the same
struct cftype.
Alexey Kodanev reported a crash, which can be reproduced:
# mount -t cgroup -o xattr /sys/fs/cgroup
# mkdir /sys/fs/cgroup/test
# setfattr -n trusted.value -v test_value /sys/fs/cgroup/tasks
# rmdir /sys/fs/cgroup/test
# umount /sys/fs/cgroup
oops!
In this case, simple_xattrs_free() will free the same struct simple_xattrs
twice.
tj: Dropped unused local variable @cft from cgroup_diput().
Reported-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/cgroup.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 5fb0942..cddf1d9 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -162,6 +162,9 @@ struct cfent { struct list_head node; struct dentry *dentry; struct cftype *type; + + /* file xattrs */ + struct simple_xattrs xattrs; }; /* @@ -908,13 +911,12 @@ static void cgroup_diput(struct dentry *dentry, struct inode *inode) } else { struct cfent *cfe = __d_cfe(dentry); struct cgroup *cgrp = dentry->d_parent->d_fsdata; - struct cftype *cft = cfe->type; WARN_ONCE(!list_empty(&cfe->node) && cgrp != &cgrp->root->top_cgroup, "cfe still linked for %s\n", cfe->type->name); + simple_xattrs_free(&cfe->xattrs); kfree(cfe); - simple_xattrs_free(&cft->xattrs); } iput(inode); } @@ -2553,7 +2555,7 @@ static struct simple_xattrs *__d_xattrs(struct dentry *dentry) if (S_ISDIR(dentry->d_inode->i_mode)) return &__d_cgrp(dentry)->xattrs; else - return &__d_cft(dentry)->xattrs; + return &__d_cfe(dentry)->xattrs; } static inline int xattr_enabled(struct dentry *dentry) @@ -2729,8 +2731,6 @@ static int cgroup_add_file(struct cgroup *cgrp, struct cgroup_subsys *subsys, umode_t mode; char name[MAX_CGROUP_TYPE_NAMELEN + MAX_CFTYPE_NAME + 2] = { 0 }; - simple_xattrs_init(&cft->xattrs); - if (subsys && !test_bit(ROOT_NOPREFIX, &cgrp->root->flags)) { strcpy(name, subsys->name); strcat(name, "."); @@ -2755,6 +2755,7 @@ static int cgroup_add_file(struct cgroup *cgrp, struct cgroup_subsys *subsys, cfe->type = (void *)cft; cfe->dentry = dentry; dentry->d_fsdata = cfe; + simple_xattrs_init(&cfe->xattrs); list_add_tail(&cfe->node, &parent->files); cfe = NULL; } |