[PATCH][next] btrfs: inode: Fix uninitialized variable bug

[PATCH][next] btrfs: inode: Fix uninitialized variable bug

[Gustavo A. R. Silva]

geom.len is being used without being properly initialized, previously.

Fix this by placing ASSERT(geom.len <= INT_MAX); after geom.len has been
initialized.

Addresses-Coverity-ID: 1491912 ("Uninitialized scalar variable")
Fixes: 1eb52c8bd8d6 ("btrfs: get rid of one layer of bios in direct I/O")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 fs/btrfs/inode.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index fce94591e092..00ea02268f54 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7637,7 +7637,6 @@ static void btrfs_submit_direct_hook(struct btrfs_dio_private *dip)
 	else
 		async_submit = 1;
 
-	ASSERT(geom.len <= INT_MAX);
 	do {
 		ret = btrfs_get_io_geometry(fs_info, btrfs_op(dio_bio),
 					    start_sector << 9, submit_len,
@@ -7647,6 +7646,8 @@ static void btrfs_submit_direct_hook(struct btrfs_dio_private *dip)
 			goto out_err;
 		}
 
+		ASSERT(geom.len <= INT_MAX);
+
 		clone_len = min_t(int, submit_len, geom.len);
 
 		/*
-- 
2.26.0

Re: [PATCH][next] btrfs: inode: Fix uninitialized variable bug

[David Sterba]

On Fri, Mar 27, 2020 at 03:01:35PM -0500, Gustavo A. R. Silva wrote:
> geom.len is being used without being properly initialized, previously.
> 
> Fix this by placing ASSERT(geom.len <= INT_MAX); after geom.len has been
> initialized.
> 
> Addresses-Coverity-ID: 1491912 ("Uninitialized scalar variable")
> Fixes: 1eb52c8bd8d6 ("btrfs: get rid of one layer of bios in direct I/O")

Thanks.  This is in a development branch so the fixup can be folded in,
we're expecting more revisions of the patchset anyway. CCing Omar.