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| author | Dan Carpenter <dan.carpenter@oracle.com> | 2012-05-28 14:16:57 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2012-05-28 14:16:57 -0400 |
| commit | bb3d132a24cd8bf5e7773b2d9f9baa58b07a7dae (patch) | |
| tree | c88fbbdb6464bfa35c047b207dd6097f3b447375 /fs/ext4/ialloc.c | |
| parent | e93376c20b70d1e62bb3246acd1bbe21fe58859f (diff) | |
| download | linux-bb3d132a24cd8bf5e7773b2d9f9baa58b07a7dae.tar.bz2 | |
ext4: fix potential NULL dereference in ext4_free_inodes_counts()
The ext4_get_group_desc() function returns NULL on error, and
ext4_free_inodes_count() function dereferences it without checking.
There is a check on the next line, but it's too late.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
Diffstat (limited to 'fs/ext4/ialloc.c')
| -rw-r--r-- | fs/ext4/ialloc.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index a044a9b77491..ea32d7e1d6e3 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -508,10 +508,12 @@ fallback_retry: for (i = 0; i < ngroups; i++) { grp = (parent_group + i) % ngroups; desc = ext4_get_group_desc(sb, grp, NULL); - grp_free = ext4_free_inodes_count(sb, desc); - if (desc && grp_free && grp_free >= avefreei) { - *group = grp; - return 0; + if (desc) { + grp_free = ext4_free_inodes_count(sb, desc); + if (grp_free && grp_free >= avefreei) { + *group = grp; + return 0; + } } } |