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| author | Al Viro <viro@ZenIV.linux.org.uk> | 2008-01-02 14:09:57 +0000 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-01-02 13:13:27 -0800 |
| commit | 831830b5a2b5d413407adf380ef62fe17d6fcbf2 (patch) | |
| tree | b08f54f15374b5b98b0b3bea20a1d2ea8d1f50e0 /fs/proc/task_nommu.c | |
| parent | ac40532ef0b8649e6f7f83859ea0de1c4ed08a19 (diff) | |
| download | linux-831830b5a2b5d413407adf380ef62fe17d6fcbf2.tar.bz2 | |
restrict reading from /proc/<pid>/maps to those who share ->mm or can ptrace pid
Contents of /proc/*/maps is sensitive and may become sensitive after
open() (e.g. if target originally shares our ->mm and later does exec
on suid-root binary).
Check at read() (actually, ->start() of iterator) time that mm_struct
we'd grabbed and locked is
- still the ->mm of target
- equal to reader's ->mm or the target is ptracable by reader.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc/task_nommu.c')
| -rw-r--r-- | fs/proc/task_nommu.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c index d8b8c7183c24..1932c2ca3457 100644 --- a/fs/proc/task_nommu.c +++ b/fs/proc/task_nommu.c @@ -165,15 +165,13 @@ static void *m_start(struct seq_file *m, loff_t *pos) if (!priv->task) return NULL; - mm = get_task_mm(priv->task); + mm = mm_for_maps(priv->task); if (!mm) { put_task_struct(priv->task); priv->task = NULL; return NULL; } - down_read(&mm->mmap_sem); - /* start from the Nth VMA */ for (vml = mm->context.vmlist; vml; vml = vml->next) if (n-- == 0) |