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| author | Vincent Li <macli@brc.ubc.ca> | 2009-09-22 16:45:36 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-09-23 07:39:40 -0700 |
| commit | fb92a4b068be96799da3748c11cbd69760e44d7b (patch) | |
| tree | da10040b94e5a0b83de42008c369aa7c3242c333 /fs/proc/task_mmu.c | |
| parent | acef82b873b6899d80e639317228f2104dae79a2 (diff) | |
| download | lwn-fb92a4b068be96799da3748c11cbd69760e44d7b.tar.gz lwn-fb92a4b068be96799da3748c11cbd69760e44d7b.zip | |
fs/proc/task_mmu.c v1: fix clear_refs_write() input sanity check
Andrew Morton pointed out similar string hacking and obfuscated check for
zero-length input at the end of the function, David Rientjes suggested to
use strict_strtol to replace simple_strtol, this patch cover above
suggestions, add removing of leading and trailing whitespace from user
input. It does not change function behavious.
Signed-off-by: Vincent Li <macli@brc.ubc.ca>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Amerigo Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc/task_mmu.c')
| -rw-r--r-- | fs/proc/task_mmu.c | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 59e98fea34a4..366b1017a4f1 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -473,21 +473,20 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { struct task_struct *task; - char buffer[PROC_NUMBUF], *end; + char buffer[PROC_NUMBUF]; struct mm_struct *mm; struct vm_area_struct *vma; - int type; + long type; memset(buffer, 0, sizeof(buffer)); if (count > sizeof(buffer) - 1) count = sizeof(buffer) - 1; if (copy_from_user(buffer, buf, count)) return -EFAULT; - type = simple_strtol(buffer, &end, 0); + if (strict_strtol(strstrip(buffer), 10, &type)) + return -EINVAL; if (type < CLEAR_REFS_ALL || type > CLEAR_REFS_MAPPED) return -EINVAL; - if (*end == '\n') - end++; task = get_proc_task(file->f_path.dentry->d_inode); if (!task) return -ESRCH; @@ -523,9 +522,8 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, mmput(mm); } put_task_struct(task); - if (end - buffer == 0) - return -EIO; - return end - buffer; + + return count; } const struct file_operations proc_clear_refs_operations = { |