From: Linus Torvalds Date: Mon, 18 Apr 2011 17:36:54 +0000 (-0700) Subject: proc: do proper range check on readdir offset X-Git-Tag: firefly_0821_release~7613^2~1596 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=d8bdc59f215e62098bc5b4256fd9928bf27053a1;p=firefly-linux-kernel-4.4.55.git 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 --- 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;