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authorLinus Torvalds <torvalds@linux-foundation.org>2011-04-18 10:36:54 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-04-18 10:36:54 -0700
commitd8bdc59f215e62098bc5b4256fd9928bf27053a1 (patch)
tree2f6e233afaf1b7f970e2f0ef0786dff4596dbd0a /fs/proc
parentc78193e9c7bcbf25b8237ad0dec82f805c4ea69b (diff)
downloadlwn-d8bdc59f215e62098bc5b4256fd9928bf27053a1.tar.gz
lwn-d8bdc59f215e62098bc5b4256fd9928bf27053a1.zip
proc: do proper range check on readdir offset
Rather than pass in some random truncated offset to the pid-related functions, check that the offset is in range up-front. This is just cleanup, the previous commit fixed the real problem. Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc')
-rw-r--r--fs/proc/base.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index dd6628d3ba42..dfa532730e55 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -3124,11 +3124,16 @@ static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldi
/* for the /proc/ directory itself, after non-process stuff has been done */
int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
{
- unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
- struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode);
+ unsigned int nr;
+ struct task_struct *reaper;
struct tgid_iter iter;
struct pid_namespace *ns;
+ if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET)
+ goto out_no_task;
+ nr = filp->f_pos - FIRST_PROCESS_ENTRY;
+
+ reaper = get_proc_task(filp->f_path.dentry->d_inode);
if (!reaper)
goto out_no_task;