Hi Andrew,
Could you please take a look at this patchset? Or should I ping
Alexey Dobriyan?
Thanks,
On 2023/1/31 23:55, Chao Yu wrote:
__proc_create() has limited dirent's max name length with 255, let's
add this limitation in proc_lookup_de(), so that it can return
-ENAMETOOLONG correctly instead of -ENOENT when stating a file which
has out-of-range name length.
Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
---
fs/proc/generic.c | 5 ++++-
fs/proc/internal.h | 3 +++
2 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 878d7c6db919..f547e9593a77 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -245,6 +245,9 @@ struct dentry *proc_lookup_de(struct inode *dir, struct dentry *dentry,
{
struct inode *inode;
+ if (dentry->d_name.len > PROC_NAME_LEN)
+ return ERR_PTR(-ENAMETOOLONG);
+
read_lock(&proc_subdir_lock);
de = pde_subdir_find(de, dentry->d_name.name, dentry->d_name.len);
if (de) {
@@ -401,7 +404,7 @@ static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent,
goto out;
qstr.name = fn;
qstr.len = strlen(fn);
- if (qstr.len == 0 || qstr.len >= 256) {
+ if (qstr.len == 0 || qstr.len > PROC_NAME_LEN) {
WARN(1, "name len %u\n", qstr.len);
return NULL;
}
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index b701d0207edf..7611bc684d9e 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -142,6 +142,9 @@ unsigned name_to_int(const struct qstr *qstr);
/* Worst case buffer size needed for holding an integer. */
#define PROC_NUMBUF 13
+/* Max name length of procfs dirent */
+#define PROC_NAME_LEN 255
+
/*
* array.c
*/
