Commit bc452b4b authored by Djalal Harouni's avatar Djalal Harouni Committed by Linus Torvalds

proc: do not allow negative offsets on /proc/<pid>/environ

__mem_open() which is called by both /proc/<pid>/environ and
/proc/<pid>/mem ->open() handlers will allow the use of negative offsets.
/proc/<pid>/mem has negative offsets but not /proc/<pid>/environ.

Clean this by moving the 'force FMODE_UNSIGNED_OFFSET flag' to mem_open()
to allow negative offsets only on /proc/<pid>/mem.
Signed-off-by: default avatarDjalal Harouni <tixxdz@opendz.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Brad Spengler <spender@grsecurity.net>
Acked-by: default avatarKees Cook <keescook@chromium.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e8905ec2
...@@ -695,8 +695,6 @@ static int __mem_open(struct inode *inode, struct file *file, unsigned int mode) ...@@ -695,8 +695,6 @@ static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
mmput(mm); mmput(mm);
} }
/* OK to pass negative loff_t, we can catch out-of-range */
file->f_mode |= FMODE_UNSIGNED_OFFSET;
file->private_data = mm; file->private_data = mm;
return 0; return 0;
...@@ -704,7 +702,12 @@ static int __mem_open(struct inode *inode, struct file *file, unsigned int mode) ...@@ -704,7 +702,12 @@ static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
static int mem_open(struct inode *inode, struct file *file) static int mem_open(struct inode *inode, struct file *file)
{ {
return __mem_open(inode, file, PTRACE_MODE_ATTACH); int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
/* OK to pass negative loff_t, we can catch out-of-range */
file->f_mode |= FMODE_UNSIGNED_OFFSET;
return ret;
} }
static ssize_t mem_rw(struct file *file, char __user *buf, static ssize_t mem_rw(struct file *file, char __user *buf,
......
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