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Subject[PATCH AUTOSEL 5.2 22/44] btrfs: trim: Check the range passed into to prevent overflow
Date
From: Qu Wenruo <wqu@suse.com>

[ Upstream commit 07301df7d2fc220d3de5f7ad804dcb941400cb00 ]

Normally the range->len is set to default value (U64_MAX), but when it's
not default value, we should check if the range overflows.

And if it overflows, return -EINVAL before doing anything.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/btrfs/extent-tree.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 5faf057f6f37f..b8f4720879021 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -11226,6 +11226,7 @@ int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range)
struct btrfs_device *device;
struct list_head *devices;
u64 group_trimmed;
+ u64 range_end = U64_MAX;
u64 start;
u64 end;
u64 trimmed = 0;
@@ -11235,16 +11236,23 @@ int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range)
int dev_ret = 0;
int ret = 0;

+ /*
+ * Check range overflow if range->len is set.
+ * The default range->len is U64_MAX.
+ */
+ if (range->len != U64_MAX &&
+ check_add_overflow(range->start, range->len, &range_end))
+ return -EINVAL;
+
cache = btrfs_lookup_first_block_group(fs_info, range->start);
for (; cache; cache = next_block_group(cache)) {
- if (cache->key.objectid >= (range->start + range->len)) {
+ if (cache->key.objectid >= range_end) {
btrfs_put_block_group(cache);
break;
}

start = max(range->start, cache->key.objectid);
- end = min(range->start + range->len,
- cache->key.objectid + cache->key.offset);
+ end = min(range_end, cache->key.objectid + cache->key.offset);

if (end - start >= range->minlen) {
if (!block_group_cache_done(cache)) {
--
2.20.1
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