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authorAlexey Dobriyan <adobriyan@sw.ru>2007-07-15 23:40:21 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-16 09:05:44 -0700
commitda58a1617343e345d435953a0f32024997a95164 (patch)
tree12a0ad4a92221d38dd8846f63063a8414c44655d /fs
parent7126dd0562c78fa393a53120155e9b265cc68f9d (diff)
/proc/*/environ: wrong placing of ptrace_may_attach() check
It's a bit dopey-looking and can permit a task to cause a pagefault in an mm which it doesn't have permission to read from. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/proc/base.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 46ea5d56e1b..d0921944e68 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -204,12 +204,17 @@ static int proc_pid_environ(struct task_struct *task, char * buffer)
int res = 0;
struct mm_struct *mm = get_task_mm(task);
if (mm) {
- unsigned int len = mm->env_end - mm->env_start;
+ unsigned int len;
+
+ res = -ESRCH;
+ if (!ptrace_may_attach(task))
+ goto out;
+
+ len = mm->env_end - mm->env_start;
if (len > PAGE_SIZE)
len = PAGE_SIZE;
res = access_process_vm(task, mm->env_start, buffer, len, 0);
- if (!ptrace_may_attach(task))
- res = -ESRCH;
+out:
mmput(mm);
}
return res;