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authorAlexey Dobriyan <adobriyan@gmail.com>2014-08-08 14:21:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-08 15:57:22 -0700
commitdbcdb504417ae108a20454ef89776a614b948571 (patch)
tree397a024e382d28f09ccb020d4a2daedd2d251e9d
parentccf94f1b4a8560ffdc221840535bae5e5a91a53c (diff)
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proc: add and remove /proc entry create checks
* remove proc_create(NULL, ...) check, let it oops * warn about proc_create("", ...) and proc_create("very very long name", ...) proc code keeps length as u8, no 256+ name length possible * warn about proc_create("123", ...) /proc/$PID and /proc/misc namespaces are separate things, but dumb module might create funky a-la $PID entry. * remove post mortem strchr('/') check Triggering it implies either strchr() is buggy or memory corruption. It should be VFS check anyway. In reality, none of these checks will ever trigger, it is preparation for the next patch. Based on patch from Al Viro. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/proc/base.c4
-rw-r--r--fs/proc/fd.c2
-rw-r--r--fs/proc/generic.c30
-rw-r--r--fs/proc/internal.h6
4 files changed, 21 insertions, 21 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 79df9ff71afd..11375216b493 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2785,7 +2785,7 @@ struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsign
unsigned tgid;
struct pid_namespace *ns;
- tgid = name_to_int(dentry);
+ tgid = name_to_int(&dentry->d_name);
if (tgid == ~0U)
goto out;
@@ -3033,7 +3033,7 @@ static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry
if (!leader)
goto out_no_task;
- tid = name_to_int(dentry);
+ tid = name_to_int(&dentry->d_name);
if (tid == ~0U)
goto out;
diff --git a/fs/proc/fd.c b/fs/proc/fd.c
index 0788d093f5d8..955bb55fab8c 100644
--- a/fs/proc/fd.c
+++ b/fs/proc/fd.c
@@ -206,7 +206,7 @@ static struct dentry *proc_lookupfd_common(struct inode *dir,
{
struct task_struct *task = get_proc_task(dir);
int result = -ENOENT;
- unsigned fd = name_to_int(dentry);
+ unsigned fd = name_to_int(&dentry->d_name);
if (!task)
goto out_no_task;
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index b7f268eb5f45..190862e89880 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -330,28 +330,28 @@ static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent,
nlink_t nlink)
{
struct proc_dir_entry *ent = NULL;
- const char *fn = name;
- unsigned int len;
-
- /* make sure name is valid */
- if (!name || !strlen(name))
- goto out;
+ const char *fn;
+ struct qstr qstr;
if (xlate_proc_name(name, parent, &fn) != 0)
goto out;
+ qstr.name = fn;
+ qstr.len = strlen(fn);
+ if (qstr.len == 0 || qstr.len >= 256) {
+ WARN(1, "name len %u\n", qstr.len);
+ return NULL;
+ }
+ if (*parent == &proc_root && name_to_int(&qstr) != ~0U) {
+ WARN(1, "create '/proc/%s' by hand\n", qstr.name);
+ return NULL;
+ }
- /* At this point there must not be any '/' characters beyond *fn */
- if (strchr(fn, '/'))
- goto out;
-
- len = strlen(fn);
-
- ent = kzalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL);
+ ent = kzalloc(sizeof(struct proc_dir_entry) + qstr.len + 1, GFP_KERNEL);
if (!ent)
goto out;
- memcpy(ent->name, fn, len + 1);
- ent->namelen = len;
+ memcpy(ent->name, fn, qstr.len + 1);
+ ent->namelen = qstr.len;
ent->mode = mode;
ent->nlink = nlink;
atomic_set(&ent->count, 1);
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 3ab6d14e71c5..a38408a1dd84 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -112,10 +112,10 @@ static inline int task_dumpable(struct task_struct *task)
return 0;
}
-static inline unsigned name_to_int(struct dentry *dentry)
+static inline unsigned name_to_int(const struct qstr *qstr)
{
- const char *name = dentry->d_name.name;
- int len = dentry->d_name.len;
+ const char *name = qstr->name;
+ int len = qstr->len;
unsigned n = 0;
if (len > 1 && *name == '0')