diff options
| author |   Xiubo Li <lixiubo@cmss.chinamobile.com> | 2017-07-12 15:51:17 +0800 |
|---|---|---|
| committer |   Nicholas Bellinger <nab@linux-iscsi.org> | 2017-07-30 15:12:32 -0700 |
| commit | c542942cb42186f99b6d715a833c7afad359f48f (patch) | |
| tree | 935be87483fc8dcd9029bae5cc61f322fe505121 | |
| parent | Linux 4.13-rc2 (diff) | |
| download | linux-dev-c542942cb42186f99b6d715a833c7afad359f48f.tar.xz linux-dev-c542942cb42186f99b6d715a833c7afad359f48f.zip | |
tcmu: Fix possible to/from address overflow when doing the memcpy
For most case the sg->length equals to PAGE_SIZE, so this bug won't
be triggered. Otherwise this will crash the kernel, for example when
all segments' sg->length equal to 1K.
Signed-off-by: Xiubo Li <lixiubo@cmss.chinamobile.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
| -rw-r--r-- | drivers/target/target_core_user.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index 80ee130f8253..db29b5cd0b95 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -563,8 +563,6 @@ static int scatter_data_area(struct tcmu_dev *udev, block_remaining); to_offset = get_block_offset_user(udev, dbi, block_remaining); - offset = DATA_BLOCK_SIZE - block_remaining; - to += offset; if (*iov_cnt != 0 && to_offset == iov_tail(*iov)) { @@ -575,8 +573,10 @@ static int scatter_data_area(struct tcmu_dev *udev, (*iov)->iov_len = copy_bytes; } if (copy_data) { - memcpy(to, from + sg->length - sg_remaining, - copy_bytes); + offset = DATA_BLOCK_SIZE - block_remaining; + memcpy(to + offset, + from + sg->length - sg_remaining, + copy_bytes); tcmu_flush_dcache_range(to, copy_bytes); } sg_remaining -= copy_bytes; @@ -637,9 +637,8 @@ static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd, copy_bytes = min_t(size_t, sg_remaining, block_remaining); offset = DATA_BLOCK_SIZE - block_remaining; - from += offset; tcmu_flush_dcache_range(from, copy_bytes); - memcpy(to + sg->length - sg_remaining, from, + memcpy(to + sg->length - sg_remaining, from + offset, copy_bytes); sg_remaining -= copy_bytes; |