Re: [PATCH 2/2] xfs_io: Fix do not loop through uninitialized var

["Darrick J. Wong" <djwong@kernel.org>]

On Fri, May 31, 2024 at 12:38:19AM +0200, Pavel Reichl wrote:
> Red Hat's covscan checker found the following issue:
> 
> xfsprogs-6.4.0/io/parent.c:115:2: var_decl: Declaring variable "count" without initializer.
> xfsprogs-6.4.0/io/parent.c:134:2: uninit_use: Using uninitialized value "count".
> 
> Currently, jdm_parentpaths() returns EOPNOTSUPP and does not initialize
> the count variable. The count variable is subsequently used in a for
> loop, which leads to undefined behavior. Fix this by returning from the
> check_parents() function immediately after checking the return value of
> the jdm_parentpaths() function.
> 
> Signed-off-by: Pavel Reichl <preichl@redhat.com>

I'm waiting on Carlos to take the xfsprogs 6.9 stuff so that I can
resend the new parent pointer code[1] for 6.10 which blows away the last
of the old SGI pptr code.

--D

[1] https://lore.kernel.org/linux-xfs/170405006341.1804688.11009892277015794783.stgit@frogsfrogsfrogs/

> ---
>  io/parent.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/io/parent.c b/io/parent.c
> index 8f63607f..93f40997 100644
> --- a/io/parent.c
> +++ b/io/parent.c
> @@ -112,7 +112,7 @@ check_parents(parent_t *parentbuf, size_t *parentbuf_size,
>  	     jdm_fshandle_t *fshandlep, struct xfs_bstat *statp)
>  {
>  	int error, i;
> -	__u32 count;
> +	__u32 count = 0;
>  	parent_t *entryp;
>  
>  	do {
> @@ -126,7 +126,7 @@ check_parents(parent_t *parentbuf, size_t *parentbuf_size,
>  			       (unsigned long long) statp->bs_ino,
>  				strerror(errno));
>  			err_status++;
> -			break;
> +			return;
>  		}
>  	} while (error == ERANGE);
>  
> -- 
> 2.45.1
> 
>