diff options
| author | Minchan Kim <minchan@kernel.org> | 2012-06-08 15:39:26 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-06-11 08:59:47 -0700 |
| commit | 374a69191d12a0525b7ffe1197abc30c4795a230 (patch) | |
| tree | 40e0a7ae2e48ded4cd5eeeb8316ccb8348f7a72d /drivers/staging/zram/zram_drv.c | |
| parent | c234434835b1f4bad9bdbae6710044cba387c9e5 (diff) | |
staging: zram: fix random data read
fd1a30de makes a bug that it uses (struct page *) as zsmalloc's handle
although it's a uncompressed page so that it can access random page,
return random data or even crashed by get_first_page in zs_map_object.
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/zram/zram_drv.c')
| -rw-r--r-- | drivers/staging/zram/zram_drv.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c index abd69d13d0a1..0cdc303ad565 100644 --- a/drivers/staging/zram/zram_drv.c +++ b/drivers/staging/zram/zram_drv.c @@ -280,26 +280,27 @@ static int zram_read_before_write(struct zram *zram, char *mem, u32 index) size_t clen = PAGE_SIZE; struct zobj_header *zheader; unsigned char *cmem; + unsigned long handle = zram->table[index].handle; - if (zram_test_flag(zram, index, ZRAM_ZERO) || - !zram->table[index].handle) { + if (zram_test_flag(zram, index, ZRAM_ZERO) || !handle) { memset(mem, 0, PAGE_SIZE); return 0; } - cmem = zs_map_object(zram->mem_pool, zram->table[index].handle); - /* Page is stored uncompressed since it's incompressible */ if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED))) { - memcpy(mem, cmem, PAGE_SIZE); - kunmap_atomic(cmem); + char *src = kmap_atomic((struct page *)handle); + memcpy(mem, src, PAGE_SIZE); + kunmap_atomic(src); return 0; } + cmem = zs_map_object(zram->mem_pool, handle); + ret = lzo1x_decompress_safe(cmem + sizeof(*zheader), zram->table[index].size, mem, &clen); - zs_unmap_object(zram->mem_pool, zram->table[index].handle); + zs_unmap_object(zram->mem_pool, handle); /* Should NEVER happen. Return bio error if it does. */ if (unlikely(ret != LZO_E_OK)) { |