[natty,natty/ti-omap4 CVE 1/5] pagemap: close races with suid execve
Andy Whitcroft
apw at canonical.com
Thu Jul 21 13:13:42 UTC 2011
From: Al Viro <viro at zeniv.linux.org.uk>
just use mm_for_maps()
Signed-off-by: Al Viro <viro at zeniv.linux.org.uk>
(cherry picked from commit ca6b0bf0e086513b9ee5efc0aa5770ecb57778af)
CVE-2011-1020
BugLink: http://bugs.launchpad.net/bugs/813026
Signed-off-by: Andy Whitcroft <apw at canonical.com>
---
fs/proc/base.c | 4 ++--
fs/proc/task_mmu.c | 7 ++-----
2 files changed, 4 insertions(+), 7 deletions(-)
diff --git a/fs/proc/base.c b/fs/proc/base.c
index f1b3b19..a86bfd3 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2797,7 +2797,7 @@ static const struct pid_entry tgid_base_stuff[] = {
#ifdef CONFIG_PROC_PAGE_MONITOR
REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
REG("smaps", S_IRUGO, proc_smaps_operations),
- REG("pagemap", S_IRUSR, proc_pagemap_operations),
+ REG("pagemap", S_IRUGO, proc_pagemap_operations),
#endif
#ifdef CONFIG_SECURITY
DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
@@ -3138,7 +3138,7 @@ static const struct pid_entry tid_base_stuff[] = {
#ifdef CONFIG_PROC_PAGE_MONITOR
REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
REG("smaps", S_IRUGO, proc_smaps_operations),
- REG("pagemap", S_IRUSR, proc_pagemap_operations),
+ REG("pagemap", S_IRUGO, proc_pagemap_operations),
#endif
#ifdef CONFIG_SECURITY
DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index c4bec29..3fe21d5 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -731,7 +731,8 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
goto out;
ret = -EACCES;
- if (!ptrace_may_access(task, PTRACE_MODE_READ))
+ mm = mm_for_maps(task);
+ if (!mm)
goto out_task;
ret = -EINVAL;
@@ -744,10 +745,6 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
if (!count)
goto out_task;
- mm = get_task_mm(task);
- if (!mm)
- goto out_task;
-
pm.len = PM_ENTRY_BYTES * (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
pm.buffer = kmalloc(pm.len, GFP_TEMPORARY);
ret = -ENOMEM;
--
1.7.4.1
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