From 57a5c24856fbbcb70a9aa90e55eed4e5e136d171 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Tue, 22 Apr 2008 01:32:44 -0400
Subject: [PATCH] [PATCH] proc_readfd_common() race fix
Since we drop the rcu_read_lock inside the loop, we can't assume
that files->fdt will remain unchanged (and not freed) between
iterations.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/proc/base.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 81d7d145292a6..7313c62e3e9dd 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1626,7 +1626,6 @@ static int proc_readfd_common(struct file * filp, void * dirent,
unsigned int fd, ino;
int retval;
struct files_struct * files;
- struct fdtable *fdt;
retval = -ENOENT;
if (!p)
@@ -1649,9 +1648,8 @@ static int proc_readfd_common(struct file * filp, void * dirent,
if (!files)
goto out;
rcu_read_lock();
- fdt = files_fdtable(files);
for (fd = filp->f_pos-2;
- fd < fdt->max_fds;
+ fd < files_fdtable(files)->max_fds;
fd++, filp->f_pos++) {
char name[PROC_NUMBUF];
int len;
--
2.39.5