[PATCH 4.19 5.4 5.15] btrfs: defrag: fix memory leak in btrfs_ioctl_defrag

[Maximilian Heyne <mheyne@amazon.de>]

Prior to commit c853a5783ebe ("btrfs: allocate
btrfs_ioctl_defrag_range_args on stack") range is allocated on the heap
and must be freed. However, commit 173431b274a9 ("btrfs: defrag: reject
unknown flags of btrfs_ioctl_defrag_range_args") didn't take care of
this when it was backported to kernel < 5.15.

Add a kfree on the error path for stable kernels that lack
commit c853a5783ebe ("btrfs: allocate btrfs_ioctl_defrag_range_args on
stack").

This bug was discovered and resolved using Coverity Static Analysis
Security Testing (SAST) by Synopsys, Inc.

Fixes: 173431b274a9 ("btrfs: defrag: reject unknown flags of btrfs_ioctl_defrag_range_args")
CC: stable@vger.kernel.org
Signed-off-by: Maximilian Heyne <mheyne@amazon.de>
---
 fs/btrfs/ioctl.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 049b837934e5..adc6c4f2b53c 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3195,6 +3195,7 @@ static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
 			}
 			if (range->flags & ~BTRFS_DEFRAG_RANGE_FLAGS_SUPP) {
 				ret = -EOPNOTSUPP;
+				kfree(range);
 				goto out;
 			}
 			/* compression requires us to start the IO */
-- 
2.40.1




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