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authorAl Viro <viro@ZenIV.linux.org.uk>2008-01-02 14:09:57 +0000
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-01-02 13:13:27 -0800
commit831830b5a2b5d413407adf380ef62fe17d6fcbf2 (patch)
treeb08f54f15374b5b98b0b3bea20a1d2ea8d1f50e0 /fs/proc/task_mmu.c
parentac40532ef0b8649e6f7f83859ea0de1c4ed08a19 (diff)
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_mmu.c')
-rw-r--r--fs/proc/task_mmu.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index c24d81a5a040..8043a3eab52c 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -397,12 +397,11 @@ 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)
return NULL;
priv->tail_vma = tail_vma = get_gate_vma(priv->task);
- down_read(&mm->mmap_sem);
/* Start with last addr hint */
if (last_addr && (vma = find_vma(mm, last_addr))) {