diff options
author | Bill O'Donnell <billodo@redhat.com> | 2017-02-07 12:59:33 -0800 |
---|---|---|
committer | Darrick J. Wong <darrick.wong@oracle.com> | 2017-02-09 10:50:25 -0800 |
commit | b20fe4730ea5c037c16631fb0df659c7b6d4b3b1 (patch) | |
tree | e397e683169623414400ea7ea900109710105d12 /fs/xfs/xfs_mount.c | |
parent | c5ecb42342852892f978572ddc6dca703460f25a (diff) | |
download | op-kernel-dev-b20fe4730ea5c037c16631fb0df659c7b6d4b3b1.zip op-kernel-dev-b20fe4730ea5c037c16631fb0df659c7b6d4b3b1.tar.gz |
xfs: correct null checks and error processing in xfs_initialize_perag
If pag cannot be allocated, the current error exit path will trip
a null pointer deference error when calling xfs_buf_hash_destroy
with a null pag. Fix this by adding a new error exit labels and
jumping to those accordingly, avoiding the hash destroy and
unnecessary kmem_free on pag.
Up to three things need to be properly unwound:
1) pag memory allocation
2) xfs_buf_hash_init
3) radix_tree_insert
For any given iteration through the loop, any of the above which
succeed must be unwound for /this/ pag, and then all prior
initialized pags must be unwound.
Addresses-Coverity-Id: 1397628 ("Dereference after null check")
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Bill O'Donnell <billodo@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'fs/xfs/xfs_mount.c')
-rw-r--r-- | fs/xfs/xfs_mount.c | 24 |
1 files changed, 15 insertions, 9 deletions
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c index 9b9540d..1f1e4ae 100644 --- a/fs/xfs/xfs_mount.c +++ b/fs/xfs/xfs_mount.c @@ -187,7 +187,7 @@ xfs_initialize_perag( xfs_agnumber_t *maxagi) { xfs_agnumber_t index; - xfs_agnumber_t first_initialised = 0; + xfs_agnumber_t first_initialised = NULLAGNUMBER; xfs_perag_t *pag; int error = -ENOMEM; @@ -202,22 +202,20 @@ xfs_initialize_perag( xfs_perag_put(pag); continue; } - if (!first_initialised) - first_initialised = index; pag = kmem_zalloc(sizeof(*pag), KM_MAYFAIL); if (!pag) - goto out_unwind; + goto out_unwind_new_pags; pag->pag_agno = index; pag->pag_mount = mp; spin_lock_init(&pag->pag_ici_lock); mutex_init(&pag->pag_ici_reclaim_lock); INIT_RADIX_TREE(&pag->pag_ici_root, GFP_ATOMIC); if (xfs_buf_hash_init(pag)) - goto out_unwind; + goto out_free_pag; if (radix_tree_preload(GFP_NOFS)) - goto out_unwind; + goto out_hash_destroy; spin_lock(&mp->m_perag_lock); if (radix_tree_insert(&mp->m_perag_tree, index, pag)) { @@ -225,10 +223,13 @@ xfs_initialize_perag( spin_unlock(&mp->m_perag_lock); radix_tree_preload_end(); error = -EEXIST; - goto out_unwind; + goto out_hash_destroy; } spin_unlock(&mp->m_perag_lock); radix_tree_preload_end(); + /* first new pag is fully initialized */ + if (first_initialised == NULLAGNUMBER) + first_initialised = index; } index = xfs_set_inode_alloc(mp, agcount); @@ -239,11 +240,16 @@ xfs_initialize_perag( mp->m_ag_prealloc_blocks = xfs_prealloc_blocks(mp); return 0; -out_unwind: +out_hash_destroy: xfs_buf_hash_destroy(pag); +out_free_pag: kmem_free(pag); - for (; index > first_initialised; index--) { +out_unwind_new_pags: + /* unwind any prior newly initialized pags */ + for (index = first_initialised; index < agcount; index++) { pag = radix_tree_delete(&mp->m_perag_tree, index); + if (!pag) + break; xfs_buf_hash_destroy(pag); kmem_free(pag); } |