* [PATCH] mm/nommu.c: add additional check for vread() just like vwrite() has done.
@ 2013-05-17 12:25 ` Chen Gang
0 siblings, 0 replies; 2+ messages in thread
From: Chen Gang @ 2013-05-17 12:25 UTC (permalink / raw)
To: Al Viro, walken, riel, khlebnikov
Cc: Andrew Morton, linux-mm, linux-kernel@vger.kernel.org
Since vwrite() has already check whether overflow, as a pair function,
vread() also need do the same thing.
Since vwrite() check the source buffer address, vread() should check
the destination buffer address.
Signed-off-by: Chen Gang <gang.chen@asianux.com>
---
mm/nommu.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/mm/nommu.c b/mm/nommu.c
index 886e07c..0614ee1 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -282,6 +282,10 @@ EXPORT_SYMBOL(vmalloc_to_pfn);
long vread(char *buf, char *addr, unsigned long count)
{
+ /* Don't allow overflow */
+ if ((unsigned long) buf + count < count)
+ count = -(unsigned long) buf;
+
memcpy(buf, addr, count);
return count;
}
--
1.7.7.6
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^ permalink raw reply related [flat|nested] 2+ messages in thread* [PATCH] mm/nommu.c: add additional check for vread() just like vwrite() has done.
@ 2013-05-17 12:25 ` Chen Gang
0 siblings, 0 replies; 2+ messages in thread
From: Chen Gang @ 2013-05-17 12:25 UTC (permalink / raw)
To: Al Viro, walken, riel, khlebnikov
Cc: Andrew Morton, linux-mm, linux-kernel@vger.kernel.org
Since vwrite() has already check whether overflow, as a pair function,
vread() also need do the same thing.
Since vwrite() check the source buffer address, vread() should check
the destination buffer address.
Signed-off-by: Chen Gang <gang.chen@asianux.com>
---
mm/nommu.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/mm/nommu.c b/mm/nommu.c
index 886e07c..0614ee1 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -282,6 +282,10 @@ EXPORT_SYMBOL(vmalloc_to_pfn);
long vread(char *buf, char *addr, unsigned long count)
{
+ /* Don't allow overflow */
+ if ((unsigned long) buf + count < count)
+ count = -(unsigned long) buf;
+
memcpy(buf, addr, count);
return count;
}
--
1.7.7.6
^ permalink raw reply related [flat|nested] 2+ messages in thread
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2013-05-17 12:25 [PATCH] mm/nommu.c: add additional check for vread() just like vwrite() has done Chen Gang
2013-05-17 12:25 ` Chen Gang
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