Re: [PATCH v2 1/2] btrfs-progs: dump-super: check array_size in print_sys_chunk_array

2017-04-20 Thread David Sterba
On Thu, Apr 20, 2017 at 04:07:56PM +0800, Lu Fengqi wrote:
> Without validation of array_size, the dump-super may lead to a bad
> memory access.
> 
> Signed-off-by: Lu Fengqi 

1-2 applied, thanks.
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[PATCH v2 1/2] btrfs-progs: dump-super: check array_size in print_sys_chunk_array

2017-04-20 Thread Lu Fengqi
Without validation of array_size, the dump-super may lead to a bad
memory access.

Signed-off-by: Lu Fengqi 
---
v2:
Accept David's advice, no longer use BTRFS_SUPER_INFO_SIZE instead of 
sizeof(*sb).
---
 cmds-inspect-dump-super.c | 11 +--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/cmds-inspect-dump-super.c b/cmds-inspect-dump-super.c
index ee2c8e3a..b65bd2d9 100644
--- a/cmds-inspect-dump-super.c
+++ b/cmds-inspect-dump-super.c
@@ -65,13 +65,20 @@ static void print_sys_chunk_array(struct btrfs_super_block 
*sb)
buf = malloc(sizeof(*buf) + sizeof(*sb));
if (!buf) {
error("not enough memory");
-   goto out;
+   return;
}
write_extent_buffer(buf, sb, 0, sizeof(*sb));
array_size = btrfs_super_sys_array_size(sb);
 
array_ptr = sb->sys_chunk_array;
sb_array_offset = offsetof(struct btrfs_super_block, sys_chunk_array);
+
+   if (array_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
+   error("sys_array_size %u shouldn't exceed %u bytes",
+   array_size, BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
+   goto out;
+   }
+
cur_offset = 0;
item = 0;
 
@@ -124,8 +131,8 @@ static void print_sys_chunk_array(struct btrfs_super_block 
*sb)
item++;
}
 
-   free(buf);
 out:
+   free(buf);
return;
 
 out_short_read:
-- 
2.12.2



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