Messages in this thread Patch in this message | | | From | Vincent Li <> | Subject | [PATCH] fs/proc/task_mmu.c v1: fix clear_refs_write() input sanity check | Date | Wed, 12 Aug 2009 16:29:54 -0700 |
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v1 fix the compiling errors and keep the type variable name.
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.
This patch is rebased on mmotm-2009-08-04-14-22.
Signed-off-by: Vincent Li <macli@brc.ubc.ca> --- 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 2079969..c7cf8f3 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -491,21 +491,20 @@ 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; @@ -541,9 +540,8 @@ 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 = { -- 1.6.0.4
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