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: v2.6.27.59~5 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2a0c421ba95bb341035cd41a4ded4f75376d3763;p=thirdparty%2Fkernel%2Fstable.git proc: do proper range check on readdir offset commit d8bdc59f215e62098bc5b4256fd9928bf27053a1 upstream. 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. Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/proc/base.c b/fs/proc/base.c index 76f9ffc6bdde5..1a38d90cf70bd 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2734,11 +2734,16 @@ 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;