aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/target/target_core_user.c
diff options
context:
space:
mode:
authorXiubo Li <lixiubo@cmss.chinamobile.com>2017-07-12 15:51:17 +0800
committerNicholas Bellinger <nab@linux-iscsi.org>2017-07-30 15:12:32 -0700
commitc542942cb42186f99b6d715a833c7afad359f48f (patch)
tree935be87483fc8dcd9029bae5cc61f322fe505121 /drivers/target/target_core_user.c
parent520eccdfe187591a51ea9ab4c1a024ae4d0f68d9 (diff)
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>
Diffstat (limited to 'drivers/target/target_core_user.c')
-rw-r--r--drivers/target/target_core_user.c11
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;

Privacy Policy