| From | Paul Gortmaker <> | Subject | [34-longterm 081/196] proc: do proper range check on readdir offset | Date | Mon, 12 Mar 2012 20:19:54 -0400 |
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From: Linus Torvalds <torvalds@linux-foundation.org>
------------------- This is a commit scheduled for the next v2.6.34 longterm release. If you see a problem with using this for longterm, please comment. -------------------
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 <torvalds@linux-foundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> --- fs/proc/base.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/fs/proc/base.c b/fs/proc/base.c index 8418fcc..268f00d 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2871,11 +2871,16 @@ 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; -- 1.7.9.3
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