2007-02-10 02:14:43

by Brian Behlendorf

[permalink] [raw]
Subject: e2fsprogs coverity patch <cid-41.diff>

Lawrence Livermore National Labs recently ran the source code
analysis tool Coverity over the e2fsprogs-1.39 source to see
if it would identify any significant bugs. The analysis
turned up 38 mostly minor issues which are enumerated here
with patches. We went through and resolved these issues
but would love to see these mostly minor changes reviewed
and commited upstream.

Brian Behlendorf <[email protected]>, and
Herb Wartens <[email protected]>

Coverity ID: 41: Resource Leak

Went through call paths pretty carefully. Looks like it is safe to free
block_buf on an early return. The call paths that I found to use block_buf all
seem to be done with block_buf after they complete. One example is calling
swap_inode_blocks() which gets all the way to ext2fs_block_iterate2(). This
function uses block_buf to set ctx_ind_buf, but is done with it once the
function is complete.

Index: e2fsprogs+chaos/e2fsck/swapfs.c
--- e2fsprogs+chaos.orig/e2fsck/swapfs.c
+++ e2fsprogs+chaos/e2fsck/swapfs.c
@@ -113,7 +113,7 @@ static void swap_inodes(e2fsck_t ctx)
dgrp_t group;
unsigned int i;
ext2_ino_t ino = 1;
- char *buf, *block_buf;
+ char *buf, *block_buf = NULL;
errcode_t retval;
struct ext2_inode * inode;

@@ -138,6 +138,8 @@ static void swap_inodes(e2fsck_t ctx)
_("while reading inode table (group %d)"),
ctx->flags |= E2F_FLAG_ABORT;
+ if (block_buf)
+ free(block_buf);
inode = (struct ext2_inode *) buf;
@@ -162,11 +164,14 @@ static void swap_inodes(e2fsck_t ctx)
swap_inode_blocks(ctx, ino, block_buf, inode);

- if (ctx->flags & E2F_FLAG_SIGNAL_MASK)
+ if (ctx->flags & E2F_FLAG_SIGNAL_MASK) {
+ if (block_buf)
+ free(block_buf);
+ }

if (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE)
- ext2fs_swap_inode(fs, inode, inode, 1);
+ ext2fs_swap_inode(fs, inode,inode, 1);
retval = io_channel_write_blk(fs->io,
@@ -176,6 +181,8 @@ static void swap_inodes(e2fsck_t ctx)
_("while writing inode table (group %d)"),
ctx->flags |= E2F_FLAG_ABORT;
+ if (block_buf)
+ free(block_buf);