[PATCH v4] xfs_db: release ip resource before returning from get_next_unlinked()

Bill O'Donnell
2024-08-09T16:20:04Z

Fix potential memory leak in function get_next_unlinked(). Call
libxfs_irele(ip) before exiting.

Details:
Error: RESOURCE_LEAK (CWE-772):
xfsprogs-6.5.0/db/iunlink.c:51:2: alloc_arg: "libxfs_iget" allocates memory that is stored into "ip".
xfsprogs-6.5.0/db/iunlink.c:68:2: noescape: Resource "&ip->i_imap" is not freed or pointed-to in "libxfs_imap_to_bp".
xfsprogs-6.5.0/db/iunlink.c:76:2: leaked_storage: Variable "ip" going out of scope leaks the storage it points to.
# 74| libxfs_buf_relse(ino_bp);
# 75|
# 76|-> return ret;
# 77| bad:
# 78| dbprintf(_("AG %u agino %u: %s\n"), agno, agino, strerror(error));

Signed-off-by: Bill O'Donnell <bodonnel@redhat.com>
---
v2: cover error case.
v3: fix coverage to not release unitialized variable.
v4: add logic to cover error case when ip is not attained.
---
db/iunlink.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/db/iunlink.c b/db/iunlink.c
index d87562e3..98d1effc 100644
--- a/db/iunlink.c
+++ b/db/iunlink.c
@@ -49,8 +49,12 @@ get_next_unlinked(

ino = XFS_AGINO_TO_INO(mp, agno, agino);
error = -libxfs_iget(mp, NULL, ino, 0, &ip);
- if (error)
- goto bad;
+ if (error) {
+ if (ip)
+ goto bad_rele;
+ else
+ goto bad;
+ }

if (verbose) {
xfs_filblks_t blocks, rtblks = 0;
@@ -67,13 +71,16 @@ get_next_unlinked(

error = -libxfs_imap_to_bp(mp, NULL, &ip->i_imap, &ino_bp);
if (error)
- goto bad;
+ goto bad_rele;

dip = xfs_buf_offset(ino_bp, ip->i_imap.im_boffset);
ret = be32_to_cpu(dip->di_next_unlinked);
libxfs_buf_relse(ino_bp);
+ libxfs_irele(ip);

return ret;
+bad_rele:
+ libxfs_irele(ip);
bad:
dbprintf(_("AG %u agino %u: %s\n"), agno, agino, strerror(error));
return NULLAGINO;
--
2.46.0