pagemap: close races with suid execve
just use mm_for_maps() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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26ec3c646e
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@ -2797,7 +2797,7 @@ static const struct pid_entry tgid_base_stuff[] = {
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#ifdef CONFIG_PROC_PAGE_MONITOR
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REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
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REG("smaps", S_IRUGO, proc_smaps_operations),
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REG("pagemap", S_IRUSR, proc_pagemap_operations),
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REG("pagemap", S_IRUGO, proc_pagemap_operations),
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#endif
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#ifdef CONFIG_SECURITY
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DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
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@ -3133,7 +3133,7 @@ static const struct pid_entry tid_base_stuff[] = {
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#ifdef CONFIG_PROC_PAGE_MONITOR
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REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
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REG("smaps", S_IRUGO, proc_smaps_operations),
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REG("pagemap", S_IRUSR, proc_pagemap_operations),
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REG("pagemap", S_IRUGO, proc_pagemap_operations),
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#endif
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#ifdef CONFIG_SECURITY
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DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
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@ -729,7 +729,8 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
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goto out;
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ret = -EACCES;
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if (!ptrace_may_access(task, PTRACE_MODE_READ))
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mm = mm_for_maps(task);
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if (!mm)
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goto out_task;
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ret = -EINVAL;
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@ -742,10 +743,6 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
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if (!count)
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goto out_task;
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mm = get_task_mm(task);
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if (!mm)
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goto out_task;
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pm.len = PM_ENTRY_BYTES * (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
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pm.buffer = kmalloc(pm.len, GFP_TEMPORARY);
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ret = -ENOMEM;
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